• Journal of Sport and Applied Science
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• v.3 no.2
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• pp.1-10
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• 2019

Purpose: With an increase of concerns towards leisure activities, water sport participation is constantly increasing. The purpose of this study is to examine the effects of exercise commitment on leisure satisfaction. Research design, data, and methodology: To accomplish the purpose, the study collected data from undergraduate students who participated water sports class in University. The sample was extracted by purposive sampling of nonprobability sampling. 281 students participated in the survey. Data were computed via correlation test, factor analysis, Cronbach's α test, one way ANOVA, and regression. Significance of all results was set to p<.05. Results: The results are like below. Frist, in terms of differences by demographics, the results indicated that significant difference between exercise commitment and leisure satisfaction by gender was shown only in psychological factor in leisure satisfaction. Second, in terms of the relationship between commitment and satisfaction, the findings pointed out that significant difference between exercise commitment and leisure satisfaction by grade was observed only in leisure satisfaction, especially on the educational part. Third, the study revealed that no significant difference by participation level was shown. Conclusions: In conclusion, the study posits that exercise commitment play a function in increasing the leisure satisfaction. Further implications were discussed.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.2
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• pp.10-21
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• 2022

A water source heat pump (WSHP) system is regarded as an energy-efficiency heating and cooling supply system for buildings due to its high energy efficiency and low greenhouse gas emissions. Recently, water sources such as river water, lake water, and raw water are attracting attention as heat sources for a heat pump system in Korea. This paper analyzed the applicability of a river water source heat pump system (RSHP). The river water temperature level was compared with the outdoor air and ground temperature levels to present applicability. In addition, the cooling and heating performance were compared through a simulation approach for the RSHP and a ground source heat pump (GSHP) applied to a large-scale office building. To compare the temperature level, the actual data were applied to the river water and the outdoor air, while the simulation results were applied to the ground circulation water. The results showed that the change in river water temperature throughout the year was similar to the change in outdoor air temperature. However, unlike the outdoor air temperature, the difference between the hourly and daily average river water temperatures was not large. The temperature level of river water was lower during the heating season and somewhat higher during the cooling season than that of the ground circulation water. Finally, the performance of the RSHP system was 13.4% lower than that of the GSHP system on an annual-based.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.515-518
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• 2003

Groundwater recharge rate can be estimated from groundwater head rebound due to rainfall. Groundwater level changes are monitored for 10 months at Yugu area. Difference between two recharge rates calculated by rainfall and by effective rainfall is 1.1%~1.6%. Since this method ignores soil water percolation during groundwater level regression, the actual recharge rate may be higher than estimated one by cumulative rainfall and groundwater level change.

• The Journal of the Korea Contents Association
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• v.17 no.2
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• pp.535-542
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• 2017

There is a big difference of discharge rate between drought and flood period in Korea since the importance of water resources management has come to the fore. To know a river characteristics, it needs to estimate river discharge accurately. River discharge is calculated using the measured velocity of cross section and the estimated area of watercourse as input parameters into continuity equation. Generally, flow rate over a river is estimated from the relation equation between level and discharge, in this case, there are weakness for only the equal depths and the equal discharge estimated. In the present study, therefore, water surface slope was estimated using measured water level of Seongseo water level observation station and measured water level using ADVM at Gangchang Bridge. And then, we developed the discharge calculation equation using water surface slope. A method to easily calculated flow rate from the measured depth of the two points that are suggested by reflecting water surface slope because natural stream is unsteady flow, not uniform flow or not steady flow.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.119-126
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• 2018

In this study, In this study, the Datum Level-based hydrography surveying system and the ellipsoid-based system were analyzed to acquire more consistent depth data. For the study, the ellipsoid-based surveying for hydrography was conducted twice for the same track line. And the depth was calculated by correcting rise and fall of water level (water level change by tidal energy and other marine environmental energies) respectively by the traditional water level correction method and ellipsoidally referenced water level correction method. there is able to check that Ellipsoid-based hydrographic surveying data is more improved than Datum Level-based hydrographic surveying data in aspect of level difference phenomenon in the same area (surveying line). This result shows that if the Ellipsoid-based hydrographic surveying is performed, the sea level change (tidal energy and other marine environmental energy) of the survey area in real time could be reflected to more consistent generating bathymetric data.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1227-1233
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• 2004

Air handling unit (AHU)'s air filter pressure difference is important for energy consumption and indoor air quality. Both energy Performance data and air filter differential pressure of AHU in real office buildings were monitored and analyzed to investigate quantitatively energy impact as dust buildup level on air filter grows. We also modeled and simulated CAV system using HVACSIM＋ program to examine the energy effect of dust buildup on filters. Through analysis of time series pressure drop data, the filter pressure difference rate has been increased due to cumulative supply air flow rate increase. As filter pressure drop increased to 1 inch water column, it is found that the supply air flow rate was decreased by 10%, the chilled water flow rate was increased by 5.9% and the pump energy consumption was increased to 5.9%.

• KCID journal
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• v.18 no.2
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• pp.15-24
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• 2011

This study was carried out to analyze characteristics of water quality and correlation among water quality parameters in Idong reservoir used for agricultural water. The pH and concentrations of DO, SS, BOD, COD, TP, Chl-a in Idong reservoir almost met the water quality standards for agricultural water, but TN concentration exceeded the water quality standards for agricultural water. All of water quality items had no significant difference between horizontal points at 95% confidence level and the Idong reservoir was possible to be treated as the single water body. As NIP ratio of the Idong reservoir is 52, TP is a limiting nutrient salt. As TN exceeds the water quality standards, it is required to preserve TP below current state to prevent water bloom by eutrophication. Therefore, reduction of phosphorus from the watershed is necessary for controlling the eutrophication of Idong reservoir.

• The Korean Journal of Community Living Science
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• v.15 no.1
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• pp.105-113
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• 2004

This study investigated the synergy effects of hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine on the lipid metabolism and antioxidant defense system of rats on hypercholesterol diets. Sprague-Dawley male rats were fed either a hypercholesterol diet with water or a hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine. The experimental groups consisted of the control group (CO), the group supplied with hot water soluble extract from Eleutherococcus senticosus(ES), and the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine(ESC). Eleutherococcus senticosus was extracted, made into 0.5% solution, and fed to the ES and ESC groups. A 3% carnitine diet was supplied to the ESC group. Hypercholesterol diets contained 18% beef tallow and 5% cholesterol. After 4 weeks of administering these diets, serum and liver were obtained and the level of serum lipid and the activities of GOT and GPT were measured. In addition, the level of liver lipid and TBARS and the activity of GSH-Px were measured. The results were as follows: 1) Weight gain and FER in the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine(ESC) was low significantly(P<0.05). 2) In the groups supplied with hot water soluble extract from Eleutherococcus senticosus(ES) and the group supplied with hot water soluble extract from Eleutherocorcus senticosus and dietarty carnitine(ESC), total serum cholesterol levels were both significantly low (P<0.05,P.0.01). 3) Serum GOT activity was significantly low(P<0.05) in the group supplied with hot water soluble extract from Eleutherococcus senticosus(ES) and in the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietary carnitine(ESC). There was no difference between serum GPT activity in the control group and the groups supplied with hot water soluble extract from Eleutherococcus senticosus or dietary carnitine. 4) Liver triglyceride was low (P.0.05) in the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine(ESC). No difference was observed in other lipid composition, TBARS level, and GSH-px activity in liver between the control group and the experimental groups. In summary, the effects of hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine on the lipid metabolism and antioxidant defense system (such as weight gain, FER, total serum cholesterol and liver triglyceride) were low when Eleutherococcus senticosus and dietarty carnitine were supplied simultaneously.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.23 no.1
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• pp.34-38
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• 1995

A diagnostic study on the summertime air mass thunderstorms occurring in the middle region of South Korea was made by analyzing the data of surface and upper air observations as well as the surface and upper level weather charts. The key parameters used in the present study are the amount of precipitable water below 850 hPa level, the vertical profiles of water vapor content and wind, and both the temperature difference and the equivalent potential temperature difference between 850 hPa and 700 hPa levels. It is found from this study that the summertime air mass thunderstorms in the middle region of South Korea can be classified into two distinct types, type I and type II. The thunderstorms of type I occur under the atmospheric conditions of high moisture content, low vertical wind shear in low levels, and conditional instability between 850 hPa and 700 hPa levels. On the other hand, the thunderstorms of type II occur under the atmospheric conditions of less moisture content, higher wind shear and conditional instability. Furthermore, our study suggests that atmospheric instability and the amount of water vapor below 850 hPa level are complementary in the development of air mass thunderstorms. The complementary nature between these two parameters may be an explanation for the thunderstorm development in the areas of low atmospheric water vapor content such as the plains of eastern Colorado.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.363-375
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• 2001

The purpose of this study is to analyse the effects of obesity management program in food attitude and food habit, body composition(body fat ratio, body fat weight, lean body mass, total body water), abdominal girth(waist, hip, thigh), and serum lipid level(cholesterol, low density lipoprotein, triglyceride, phospholipid, NE fatty acid, high density lipoprotein) of middle aged women. Data for the study were collected from July 4 to August 25, 2000. The study objects were 20 middle aged women(10 controls and 10 experimental objects) from 40 to 50 years old who had body fat ratio more than $30\%$ and waist girth more than 80cm. The results were as follows: 1. Similarity test between experimental group and control group processed by serum HDL level showed the significant difference(t=3.25, p=0.004), but that processed by age, body weight, body fat ratio, body fat weight, lean body mass, total body water, waist girth, hip girth, thigh girth, cholesterol level, LDL level, triglyceride level, NE fatty acid level, food attitude and food habit score showed no significant difference(p>0.05). These findings imply that the two groups are similar in the sample distribution. 2. The effects of the abdominal obesity management program The obtained results indicate that the abdominal obesity management program in middle aged women changes the food attitude & the food habit. decreases the body fat ratio & the body fat weight and increases the lean body mass, and decreases the girth of waist & hip and the serum level of cholesterol & LDL. Therefore, it is concluded that the abdominal obesity management program can be applied for nursing intervention to decrease the body fat weight and abdominal obesity.