• Journal of the Korean Society of Visualization
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• v.21 no.2
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• pp.14-23
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• 2023

The pressure difference across stenotic blood vessels is a commonly used clinical metric for diagnosing many cardiovascular diseases. At present, most clinical pressure measurements rely solely on invasive catheterization. In this study, we propose a novel method for non-invasive pressure estimation using the incompressible Navier-Stokes equations and a 3D multi-path integration approach. We verify spatio-temporal convergence on an in-silico dataset of a cylindrical straight pipe phantom with steady and pulsatile flow fields. We then evaluate the proposed method on an in vitro dataset of reconstructed control, pre-operative, and post-operative carotid artery cases acquired from 4D flow MRI. The performance of our method is compared to existing approaches based on the pressure Poisson equation and work-energy relative pressure. The results demonstrate the proposed method's high accuracy, robustness to spatio-temporal subsampling, and reduced sensitivity to noise, highlighting its great potential for non-invasive pressure estimation.

• Journal of Korean Public Health Nursing
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• v.18 no.2
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• pp.312-329
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• 2004

This study was examined 718 workers who had consistent blood pressure results in 2001 and 2002 general health examinations that were held at a work places managed by a health care agency in Seoul. Significant results are found as follows by analysing SPSS 11.0 on the result of self-recorded questionnaires investigated from Mar 1, 2003 to April 30, 2003. 1. A sampled healthy group and a sampled unhealthy group had significant differences in four variables out of possible nineteens that are sex, age, marriage and occupation. The unhealthy group had more males than females, more aged (over 50 years old) than youngers (under 50 years old), more married than singles, more manufacturing workers than non-manufacturing workers. In the case of systolic blood pressure, as the healthy group had 16.52mmHg while that of the other group had 149. 58mmHg, 33.06mmHg of difference between those groups were detected. In the case of diastolic blood pressure, 74.93mmHg of the healthy group and 96.53mmHg of the unhealthy group yielded 21.60mmHg of difference between them. This result implies that a guidance of health care is required to be aware of 20-30mmHg volatility in blood pressure rate or to understand and treat properly own blood pressure. as it is difficult to detect hypertension in early stage due to no initial symptom. According to the result. an establishment of management system of workers, companies and health care agencies is required for consist health care. 2. In terms of risky habits to health, the unhealthy group had more proportion of past smokers, over-twice-a-week drinkers, people with higher obesity rate. However, in terms of excercise, the proportion of regularly exercising people is higher in the unhealthy group while that of non-exercising people is higher in the healthy group. On the other hand. the average grade of health practicing behaviour in two groups are not significantly different as the health group had 3.00 out of possible 6.00 while the other had 3.10. This result means that as workers are not interested in health practicing behaviour. health promoting programmes must be developed in such a way of various method of motivations and incentives. Particularly this implies that distortional objectives of exercises should be readjusted through health guidance. 3. Systolic blood pressure in the healthy group can be explained by sex and the obesity rate while that in the unhealthy group can be explained by subjective health awareness and the obesity. Diastolic blood pressure in the healthy group can be explained by sex and the obesity rate like the former. The obesity rate was significant variable affecting the blood pressure of both groups, and particularly the effect to the unhealthy group was remarkably higher than that to the healthy group. Therefore, this research identified that the health care on the blood pressure of workers is not only limited to hypertension patients, but also extended to all workers. In order for consistent care, an establishment of management system of workers, companies and health care agencies is required.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.682-687
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• 1999

The destruction of tissues by volume increase at food freezing is accepted as one of the factor responsible for quality damage. For this reason, the internal pressure developed in meats were investigated with a pressure transducer during freezing, frozen storage and thawing. Increasement of 6.33% for volume and $942.17\;kg/cm^2$ for density at $-20^{\circ}C$ for beef were shown. In quick and slow freezing of beef, internal pressure reached to highest point after reached to the lowest point at initial of the zone of ice crystal formation. The internal pressure was approximately $8{\sim}10\;psig$ and pressure difference was about 1 psig, which was bigger in immersion freezing than that of still-air freezing. During frozen storage of pork, internal pressure of $1.84{\sim}2.32\;psig$ occurred repeatedly as a function of sample weight at material temperature difference of ${\pm}1^{\circ}C$. The internal pressure during thawing of pork was decreased slowly after rapid increase to the maximum for less than 5min at the beginning of thawing. Internal pressure value at thawing was higher than that at freezing in most cases. Internal pressure of beef with thermal equalized freezing was about $1{\sim}4\;psig$, which was lower than that of non-thermal equalized freezing. Also, freezing time was shortened to $10{\sim}20%$.

• Food Science and Preservation
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• v.10 no.4
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• pp.459-465
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• 2003

This study was carried out to investigate the changes in internal pressure according to various freezing methods, as basic research to protect the destruction of tissues when fruits and vegetables are frozen. The rate of weight loss, caused by the freezing of fruits and vegetables, was found to be the least (0.44∼1.38％) when the immersion freezing method was applied. The difference in the rate of weight loss was the highest when freezing methods were applied to watermelon, and the freezing rate of watermelon whose moisture contents were greater have relatively greater influence on the weight loss. The difference in internal pressures was the least and caused by the volume increase and decrease, when pear, apple, and melon were frozen using the immersion freezing method, while the diffeyence the greatest when the air-blast freezing method was used. As the freezing rate was greater, the internal pressure was less. However, the internal pressure of strawberry and watermelon was the greatest when the immersion freezing method was applied. Frozen without using the thermal equalizing method, the change in internal pressure of fruits was about 2 psig. In contrast, the internal pressure of watermelon applied with the thermal equalizing method was changed in a way similar to that of watermelon not applied with the method, but the former generated a certain level of internal pressure and maintained a significantly low level of internal pressure (about 1.3 psig). When thawed, the internal pressure of samples to which the thermal equalizing method was applied was less than that of what the thermal equalizing method was not applied to. In comparison with the application of multi-step thermal equalizing method, 3∼4 times of application of the thermal equalizing method to the freezing resulted in the decrease of fluctuation range of internal pressure.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.299-311
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• 2020

This paper analyzes the distribution of water vapor pressure and relative humidity in complex terrains by collecting weather observation data at 6 locations in the valley in Jungdae-ri, Ganjeon-myeon, Gurye-gun, Jeolla South Province and 14 locations in Akyang-myeon, Hadong-gun, Gyeongsang South Province, which form a single drainage basin in rural and mountainous regions. Previously estimated water vapor pressure used in the early warning system for agrometeorological hazard and actual water vapor pressure arrived at using the temperature and humidity that were measured at the highest density (1.5 m above ground) at every hour in the valley of Jungdae-ri between 19 December 2014 and 23 November 2015 and in the valley of Akyang between 15 August 2012 and 18 August 2013 were compared. The altitude-specific gradient of the observed water vapor pressure varied with different hours of the day and the difference in water vapor pressure between high and low altitudes increased in the night. The hourly variations in the water vapor pressure in the weather stations of the valley of Akyang with various topographic and ground conditions were caused by factors other than altitude. From the observed data of the study area, a coefficient that adj usts the variation in the water vapor pressure according to the specific difference in altitude and estimates it closer to the actual measured level was derived. Relative humidity was simulated as water vapor pressure estimated against the saturated water vapor pressure, thus, confirming that errors were further reduced using the derived coefficient than with the previous method that was used in the early warning system.

• Journal of Preventive Medicine and Public Health
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• v.22 no.3 s.27
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• pp.303-312
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• 1989

To show the distribution and change of blood pressure according to age and to find factors affecting the level of blood pressure in primary school children, a follow-up study was conducted from 1986 to 1989 on 401 first grade children attending primary school in Kangwha County in 1986 and their parents. The blood pressure of the children was significantly increased according to age. The average annual increase was 1.8mmHg in systolic blood pressure and 2.5mmHg in diastolic blood pressure. The level of blood pressure did not show any significant difference in both sexes. Among children who were at or above the 80th percentile of blood pressure in the first grade, 35 and 30% of them have remained at the same level of systolic and diastolic blood pressure respectively in the fourth grade. But we could not find any significance in the tracking of blood pressure of children who were at or above the 90th percentile of blood pressure in the first grade. Weight and pulse rate were shown to be significant factors affecting systolic blood pressure in children of both sexes and mother's blood pressure and skinfold thickness were also affected systolic blood pressure in girls. The variables significantly affecting diastolic blood pressure were arm circumference and pulse rate for boys and height and pulse rate for girls.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.604-609
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• 2008

Purpose : Obesity in children and adolescence is highly correlated with adult obesity, which can provoke hypertension. Therefore, it is important to evaluate the blood pressure of obese children regularly. In this study, the results of ambulatory blood pressure monitoring (ABPM) in obese children and adolescents were evaluated. Methods : ABPM was conducted for selected patients who visited Handong University Sunlin Hospital from Feb. 1, 2006 to Dec. 1, 2007. The patients were classified into 3 groups: group 1 was normal, group 2 had normal casual blood pressure and a body mass index over the 95th percentile, and group 3 had high casual blood pressure over 120/80 mm Hg and a body mass index over the 95th percentile. Systolic and diastolic 24-hour blood pressure was measured, including both day and night. Results : There were 49 patients in the study. The results showed a significant difference for average systolic blood pressure between the three groups ($105.1{\pm}4.7$, $111.0{\pm}7.1$, $117.8{\pm}6.6mmHg$, P<0.001), but for average diastolic blood pressure only between groups 1 and 3 ($69.1{\pm}5.3$, $77.9{\pm}6.3mmHg$, P=0.001). In the daytime, only groups 1 and 3 showed a statistically significant difference for systolic and diastolic blood pressure. During the night the systolic pressure of group 3 was significantly higher than the other groups, but the diastolic pressure of group 3 was only higher than that group 1. No statistical difference was found in night dips among the groups. Conclusion : Ambulatory blood pressure monitoring in children and adolescents showed statistically higher blood pressure in obese patients with high casual blood pressure.

• Biomedical Science Letters
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• v.26 no.1
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• pp.28-36
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• 2020

High blood pressure (HTN) is a condition in which blood pressure is kept higher than normal. Blood pressure trait measures systolic blood pressure (SBP) which is the highest pressure and diastolic blood pressure (DBP) which is the lowest blood pressure. Pulse pressure (PP) is the difference between systolic and diastolic blood pressure. Hypertension is known as a disease caused by the interaction of the environment and genetic factors. To date, studies have been conducted to find genes associated with hypertension. Genome-Wide Association Study (GWAS) analysis using European data from the UK Biobank reported new 535 loci were associated with blood pressure trait. Among them, 12 genes have been reported to have a significant correlation with SBP, DBP and PP. In the study, 12 genes polymorphisms were extracted based on KARE (Korean association resource) and then we performed linear regression of blood pressure trait. As a result, 6 SNPs of the 3 genes (rs12355413 and rs11006736 of ARMC4, rs2290883, rs2290884 and rs11039014 of LRP4, rs7234941 of BCL2) showed statistically significant correlation (P<0.05) with blood pressure trait. Of the 3 genes, 6 SNPs in 2 genes (rs9651357, rs12355413, rs11006736, rs1889522 of ARMC4 and rs4987774, rs7234941 of BCL2) showed significant correlation with hypertension. These results suggest that genetic polymorphisms of ARMC4, LRP4 and BCL2 genes are associated with blood pressure traits and hypertension in Korean population. Moreover, we expected to help understand the pathogenesis of hypertension.

• PNF and Movement
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• v.21 no.2
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• pp.185-192
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• 2023

Purpose: This study aimed to confirm the effectiveness of the diaphragm stretching technique as a treatment method for low back pain by evaluating maximum inspiratory pressure, maximum expiratory pressure, and changes in back mobility in patients with low back pain. Methods: Thirty-four patients with low back pain were randomly divided into two groups: an experimental group and a control group. The diaphragm stretching technique was conducted in the experimental group, and the placebo intervention was conducted in the control group. The diaphragm stretching technique was conducted once, maintaining tension for 7 min. The placebo intervention was conducted in the same position as the diaphragm stretching technique, but with only light contact maintained without pressure. Maximum inspiratory pressure, maximum expiratory pressure, and back mobility were measured before and after the intervention, and the changes were compared and analyzed. A paired sample t-test was used to compare measurements within the group before and after the intervention. An independent t-test was used to compare the experimental and control groups. Statistical significance (α) was set at 0.05. Results: In the experimental group, maximum inspiratory pressure, maximum expiratory pressure, and back mobility increased significantly after the intervention (p < 0.05). However, there was no significant difference in the changes in all areas of the control (p > 0.05). As a result of comparative analysis of changes before and after the intervention, there were significant differences in maximum inspiratory pressure, maximum expiratory pressure, and back mobility only in the experimental group (p < 0.05). Conclusion: The diaphragm stretching technique improved maximum inspiratory pressure, maximum expiratory pressure, and back mobility compared to the placebo intervention. Therefore, the diaphragm stretching technique can be recommended as a physical therapy intervention to improve pain in patients with LBP.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.70-75
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• 2016

Recently, coastal erosion has been widely in progress and the erosion level becomes also serious in the world wide, espeically in East Sea in Korea. Since it would threaten the life, economics and security risk, it is necessary to much comprehend the reason why coastal erosion has occurred according to the geographical characteristics. Meanwhile, analysis about hydrodynamics of the solitary wave such as tunami in swash zone is needed for the best management practice of coastal erosion. Solitary wave is nonlinear wave and can be reproduced in the laboratoy scale by openning suddenly a sluice gate with water head difference, of which methodology was found in the literature, since it could be simply determined by a significant wave height. Thus, in this sutdy the generation of solitary wave was experimentalized using the sluice gate. Experimental conditions were classified by angles of a beach slope, a water level in a beach slope and a difference of water level between in a headtank and a channel bed. Two kinds of dimensionless analyses based from experimental results in this study were presented; the first analysis indicates nondimensionalization between the wave height and the water level in a beach slope in order to investigate characteristics of solitary wave approaching the beach. The second shows the other nondimensionalization between dynamic pressure and static pressure on a beach slope to investigate the relationship between wave breaking and wave pressure. Under the same conditions as laboratory experiments, the numerical results computed with a SWAN model embedded in FLOW 3D were compared in terms of wave height, and pressure on the beach slope, which shows good agreement with each other. Overall results from this study could provide fundamental hydraulic data for the reliabile verification of numerical simulation results about coastal erosion in swash zone caused by solitary waves.