• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.7-11
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• 1992

Body water compartments in vivo were determined in Holstein cattle with age ranging from 5 to 521 days to obtain an equation to estimate volumes of body water. Live weight ranged from 47 to 480 kg. Compartments were determined as antipyrine space for total body water (TBW), thiocyanate space for extracellular water (ECW) and Evans blue dye space for plasma water (PW). Body water compartments expressed as a percentage of live weight decreased as age in days increased and significantly correlated with age in days. Regression analyses revealed that prediction equations had low accuracy. Regression equations of body water compartments on live weight (WT, kg) were useful for the prediction of body fluid with a high accuracy. Live weight significantly regressed on age in days (Day), which was inferred to be utilized for estimation of standardized live weight in case animals were emaciated by certain causes such as severe diarrhea or dehydration. In conclusion, following equations were presented to estimate body water compartments of cattle in vivo : TBW in liters = $0.556({\pm}0.007)WT+10$, r = 0.993, $SE{\pm}0.7$ ECW in liters = $0.321({\pm}0.008)WT+10$, r = 0.978, $SE{\pm}0.8$ PW in liters = $0.0502({\pm}0.0012)WT+1.6$, r = 0.0983, $SE{\pm}0.1$ WT (kg) = $0.772({\pm}0.018)Day+24$, r = 0.982, $SE{\pm}2.3$.

• 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.

• Childhood Kidney Diseases
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• v.14 no.2
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• pp.111-119
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• 2010

The maintenance of the osmolality of body fluids within a very narrow physiologic range is possible by water balance mechanisms that control the intake and excretion of water. Main factors of this process are the thirst and antidiuretic hormon arginine vasopressin (AVP), secretion regulated by osmoreceptors in the hypothalamus. Body water is the primary determinant of the osmolality of the extracellular fluid (ECF), disorders of body water homeostasis can be divided into hypo-osmolar disorders, in which there is an excess of body water relative to body solute, and hyperosmolar disorders, in which there is a deficiency of body water relative to body solute. The sodium is the predominant cation in ECF and the volume of ECF is directly proportional to the content of sodium in the body. Disorders of sodium balance, therefore, may be viewed as disorders of ECF volume. This reviews addresses the regulatory mechanisms underlying water and sodium metabolism, the two major determinants of body fluid homeostasis for a good understanding of the pathophysiology and proper management of disorders with disruption of water and sodium balance.

• Journal of Chest Surgery
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• v.28 no.11
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• pp.973-976
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• 1995

The assessment method of human body composion by bioelectrical impedance is very simple, safe, rapid and noninvasive. Based on prediction formulas for total body water from bioelectrical impedance, the observed weight loss should be associated with an increase in impedance. However in edematous patients for dialysis, the calculated total body water loss as calculated from impedance were overestimated and significantly higher than the weight loss after dialysis. So determination of impedance were made in 50 edematous patients before, during and after dialysis. Mean weight loss, which was assumed to be only loss of water was 1719$\pm$ 866 gr and mean impedance change was 71.0 $\pm$ 23.0 Ohm under 50kHz. Body weight loss was highly correlated [r>0.81 with the increase in body impedance under variable frequencies[1, 10, 20, 30, 40, 50 kHz . But there were no differences between frequences. In conclusion, clinical application of bioelectrical impedance method is useful for individual edematous patients with new correlation equation[Y=230+26.8X, X;Impedance change, Y;Calculated total body water loss .

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1371-1388
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• 2023

Floods are becoming more severe and frequent due to global warming-induced climate change. Water disasters are rising in Korea due to severe rainfall and wet seasons. This makes preventive climate change measures and efficient water catastrophe responses crucial, and synthetic aperture radar satellite imagery can help. This research created 1,423 water body learning datasets for individual water body regions along the Han and Nakdong waterways to reflect domestic water body properties discovered by Sentinel-1 satellite radar imagery. We created a document with exact data annotation criteria for many situations. After the dataset was processed, U-Net, a deep learning model, analyzed water body detection results. The results from applying the learned model to water body locations not involved in the learning process were studied to validate soil water body monitoring on a national scale. The analysis showed that the created water body area detected water bodies accurately (F1-Score: 0.987, Intersection over Union [IoU]: 0.955). Other domestic water body regions not used for training and evaluation showed similar accuracy (F1-Score: 0.941, IoU: 0.89). Both outcomes showed that the computer accurately spotted water bodies in most areas, however tiny streams and gloomy areas had problems. This work should improve water resource change and disaster damage surveillance. Future studies will likely include more water body attribute datasets. Such databases could help manage and monitor water bodies nationwide and shed light on misclassified regions.

• 한국노년학
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• v.38 no.3
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• pp.537-550
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• 2018

The purpose of this study was to investigate the status of total body water and it's influencing factors in community elderly. In this descriptive study, data were collected from 135 elderly at senior citizen center, from October 4 2016 to February 28 2017. Surveys using questionnaire and anthropometric measurements for BMI and total body water were done for data collection. The results of the study showed that while most of the subjects of the study showed total body water within the appropriate range, some elderly especially elderly women show a degraded total body water. Total body water showed significant difference according to sex, body mass index, number of chronic illness, number of medication and urinary incontinence levels. Significant influencing factors were BMI(${\beta}=-0.51$, p=<.001), sex(${\beta}=-0.47$, p=<.001) and this regression model explained 51% of the variance in total body water. In the future, attention needs to be paid to the total body water of the elderly in the local community, especially to the elderly women with risk factors.

• The Journal of Korean Medicine
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• v.24 no.3
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• pp.130-137
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• 2003

Water, in a living being, is as essential as the essence derived from food is in maintaining one's life. The concepts are expressed in forms of "food and drink" and "drink-food" in the ${\mathbb{\ulcorner}}Hwangjenakyoung{\mathbb{\lrcorner}}$ and most of the other oriental medicine related references. Following the steps of the human body's metabolism, the water source builds up characteristic formations, such as bodily fluids (blood/perspiration/urine/essence), in each transforming phase according to the nature of the Ki that propels the transformation. Furthermore, each characteristic formations has its' own suitable duties, distinctive features and its field of activation. The vital energy of life is identified as a positive property due its fluidity and its formless nature. In order for this vital energy to come into its own, it needs to weld into one with the material-natured body of the negative property which will embrace the positive property and transform it into body fluid. Water taken into a body will undergo the first activation of Ki, dissolving the Wigi and the Wongi and transforming into the primary body fluid. The delicates among the dissolved Ki will once again go through a transformation in the Jungcho. It will turn into red blood, with influence of the vital function. When the vital energy completes its duties in all parts of the body, it combines with water again and transforms into the secondary bodily fluid. This is when the Takgi gets filtered and the new enriched essence is created.

• Korean Journal of Oriental Medicine
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• v.9 no.1
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• pp.65-79
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• 2003

Many of the diseases that occur in a life being are either closely related to water, or they occur by loss or deterioration of water metabolism. There are six parts of study on this subject in ${\ulcorner}$Dongeubogam${\lrcorner}$. The parts are, the part of Jinaek the part of Dameum the part of Sobyeon the part of Bujong the part of Changman and the part of Seub. In these parts, it mentions loss of perspiration, abnormal urination, edema, abdominal dropsy, formation of abnormal body fluid and intrusion of dampness into the body and etc as the abnormal water metabolism. Loss of perspiration and urination is a process of eliminating the dampness in the body. Perspiration would be the abnormality of yanghwa[陽化]. Urination would be the loss of eumhwa[陰化]. Eum[飮] is the fluid accumulated in the body that failed to go through the process of Cihwa[氣化]. Dam[痰] is formed when the body fluid is heated by the smoking-fire. Meanwhile, the dampness occurs when the water penetrates into the bones, muscles and joints. Edema and abdominal dropsy are both outcomes of accumulated body fluid. Edema is the liquified body fluid congested on the surface or the peripheral ends of the body. Abdominal dropsy is congestion of fluid, that lost the characteristic of blood due to blood deterioration, in the abdominal part.