• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.4
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• pp.223-233
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• 2010

Spatio-temporal variations of long-term water qualities (COD, SS, $Chl-{\alpha}$, N-related nutrients (TN, TDN, $NO_3^-$, $NH_4^+$), P-related nutrients (TP, TDP, $PO_4^{3-}$)) at two stations (St. SD, St. GG) in the Geumgang Reservoir were investigated from August 2001 to July 2008. Statistical methods such as t-test, factor analysis, and multi-regression analysis were applied to the water quality data in the reservoir as well as mass balances on TP. From the temporal comparisons of the water qualities between 2002 and 2007, average concentrations of $NH_4^+$, $PO_4^{3-}$, and TDP gradually decreased down by 60%, 24%, 52% in 2007. However, those of TP and $Chl-{\alpha}$ increased to 99% and 423% during the period. From the spatial comparisons between the two stations, St. GG showed higher concentrations for all of the N- and P-related nutrients than in St. SD, while opposite result for the $Chl-{\alpha}$. The factor analysis showed that "the seasonal variations of N- and P-related nutrients" were the two dominant factors occupying 49% of total variances of water qualities. Based on this result, multi-regression analysis executed for the two most influential parameters (TP and $Chl-{\alpha}$) focusing on the seasonal variations of these parameters: SS and $Chl-{\alpha}$ has contributed decisively to the concentrations of TP during the wet and dry season, respectively. On the other hand, COD and TP has been important for the $Chl-{\alpha}$ during the wet and dry season, respectively. From the established mass balances of TP loadings in the Geumgang Reservoir, Other Sources (60%) occupied the greatest contribution and Fluvial Input (38%) and Sediment (1%) during the wet season. However, both Fluvial Water (48%) and Other Sources (47%) supplied comparable amount of inputs and Sediment (5%) showed significantly increased input during the dry seasons. Recently especially during the dry winter seasons, migrating bird's excretion was estimated to contribute up to 8% of total TP input and 21% of Other Sources.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.269-278
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• 1986

The purpose of this study was to know the effect of shourt termed fasting on the usage of metabolic energy sources and the metabolic differences between non-athletic and athletic subjects. Subjects were divided into non-athletic and athletic group and exercise was loaded on both groups after feeding and fasting. Exercise was loaded by a treadmill running at the speed of 8km/hour for 30 minutes in both groups. The experiment yielded following results. In the fed state, the level of plasma FFA increased markedly after 15 and 30 minutes of exercise compared with it's level of pre-exercise period in both groups. In the fasted state, the level of plasma FFA in non-athletic group increased steadily according to the duration of exercise, while it's level in athletic group showed no changes. At pre-exercise period, the level of plasma FFA was higher in fasted state than fed state. Immediately before the exercise and 15 and 30 minutes after the exercise, blood for the determination of plasma free fatty acid(FFA), glucose, triglyceride(TG)and cholesterol was sampled from antecubital vein, and simultaneously heart rate was measured. In the fed state, the level of plasma glucose was increased mildly according to exercise, and in the fasted state it's level increased according to exercise in both groups also. In the fasted state, the level of plasma TG was lower than that in the fed state. The level of plasma TG and cholesterol in the fed state was no changed by the exercise from the pre-exercise period. The level of plasma cholesterol in athletic group had tendency to lower than that in non-athletic group. Heart rate increased markedly according to exercise in both groups, but the athletic group's increasing rate of heart rate was lower than the non-athletic group's heart rate increased according to exercise and athletic groups heart rate increased early period of exercise, but did not change during lates post-period of exercise.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.4
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• pp.32-41
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• 2001

We measured the fluxes of COD, TN and 55 in addition to composition and quality of sediment in Komso Bay, West Coast of Korea. The fluxes of TN, SS and COD were measured during flood tide and ebb tide in April and August, 2000. Denitrification rates in the sediments was also measured by direct produced $N_2$ gas technique on April and August from 1999 to 2000 in the same sea area. The composition of the sediments were 0.33~5.67 % of sand, 20.2~25.6 of gravel and 68.7~77.0 % of silt. Ignition loss of the sediments were 6.58~7.50 %. The concentration of hydrogen sulfide in the sediments were 0.028~0.326 mg/gㆍdry and oxidation reduction potential of the sediments were -28~-15 mV Diurnal fluxes of COD, total nitrogen, and suspended solids with tidal current and denitrification rate in the tidal flat have been determined in Komso Bay The diurnal net flux of COD was same in April. While 14.4 ton COD/hr of net influx into the tidal flat was recorded in August. The diurnal net influx of total nitrogen was 0.16 ton N/hr in April and 1.13 ton N/hr in August. The diurnal net influx of suspended solids was 0.05 ton SS/hr in April, and also net influx of suspended solids was 0.29 ton SS/hr in August. The overall purification ability of the tidal flat were estimated 0.00~5.69 g COD/$m^2/day$, 0.06~0.45 g N/m²/day and 0.02~0.12 g SS/$m^2/day$ for COD, TN and SS, respectively. Denitrification rate was 0.009~1.720 m mole ${N_2}/m^2/day$ (average 0.702 m mole ${N_2}/m^2/day$) in April and 0.033~0.133 m mole ${N_2}/m^2/day$ (average 0.077 m mole ${N_2}/m^2/day$) in August, 1999. 0.000~l.909 m mole ${N_2}/m^2/day$ (average 0.756 m mole ${N_2}/m^2/day$) in April, 0.000~1.691 m mole ${N_2}/m^2/day$ (average 0.392 m mole ${N_2}/m^2/day$) in August, 2000. Even with a wide range of denitrification rate depending on the sampling location and studied periods, the average denitrification rate was estimated 0.482 m mole ${N_2}/m^2/day$ in the tidal flat of Komso Bay.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.2
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• pp.133-141
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• 2012

Effects of temperature and salinity on the growth of the toxic dinoflagellate $Alexandrium$ $tamarense$ and $A.$ $catenella$ isolated from the southern coast of Korea were examined in the laboratory. Growth experiment was conducted under the following combinations of temperature and salinity; 10, 15, 20, 25 and $30^{\circ}C$, 10, 15, 20, 25, 30 and 35 psu at a constant irradiance of 300 ${\mu}mol$ photons $m^{-2}s^{-1}$. Temperature and salinity conditions for maximum growth rate were indicated as follows: temperature $15^{\circ}C$ and salinity 30 psu (0.31 $d^{-1}$) in $A.$ $tamarense$, temperature $25^{\circ}C$ and salinity 30 psu (0.36 $d^{-1}$) in A. catenella. Temperature and salinity ranges for optimum growth condition of two species were $10{\sim}20^{\circ}C$, 25~35 psu and $120{\sim}30^{\circ}C$, 25~35 psu, respectively. The result of two-factor ANOVA indicated significant effects (P<0.001) of temperature and salinity on the growth rate, and two species were more effected by a temperature than a salinity on the growth. In addition, prediction equations were obtained through the multiple regressions of the specific growth rates as ${\mu}=0.04+0.0193T-0.0339S- 0.0005T^2+0.0021S^2+0.00073TS-0.000022T^3-0.000038S^3+0.00000086TS^2-0.0000255T^2S$ in $A.$ $tamarense$ and ${\mu}=1.01-0.1288T-0.0778S+0.0067T^2+0.0038S^2+0.00204TS-0.0001T^3-0.000059S^3-0.0000131TS^2-0.0000392T^2S$ in $A.$ $catenella$. Correlation coefficient between experimental values and simulated values was highly indicated. These results seem to provide information for understanding the spreading mechanism of $A.$ $tamarense$ and $A.$ $catenella$.

• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1061-1066
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• 2003

Purpose : The rising prevalence of childhood obesity may be due to an energy imbalance between food intake and energy expenditure. Recently, consumption of beverages in children has increased. The aim of this study is to provide useful information for the prevention and the control of childhood obesity by assessment of variable beverage consumption. Methods : Fight hundred seventy seven children(M : F=1 : 1.02, mean age; 9.7 years) from two primary schools in Seoul in May 2003 were enrolled. Body mass index(BMI) was calculated and the degree of obesity was classified into normal, overweight and obese groups by BMI percentile. Parental BMI, socio-economic factor, 3-day dietary intake, calory intake and beverage intake were examined by questionnaires. We researched beverages and classified them into six categories, milk, other milk products, soda, sports beverage, other beverage. Results : The prevalence of obesity was 7.2%. The parental BMI of the obese group were higher than those of the other groups. There was no significant difference in birth weight, or parents' intellectual and economic levels between the obese group and the other groups. There was no significant difference in daily total calory intake between the obese group and the other groups. The obese group of 7-9 year-old-males was higher than the other groups in sodas, and sports beverages intake. The obese group of 10-12 year-old-males was higher than the other groups in total beverage intake and other beverage intakes. The obese group of 10-12 year-old-females was higher than the other groups in other milk products. Conclusion : Excessive intake of beverages is associated with childhood obesity. Efforts to decrease intake of beverages may be important approaches to counter the rise in the prevalence of obesity.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.308-316
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• 2015

This study was conducted to investigate the situation of ICT apply to plastic greenhouse, and the results be apply to design of new one. A CFD analysis were conducted to monitering the ventilation and energy saving of the single span greenhouse newly designed. The causes of delay to apply ICT to plastic greenhouse are the high cost for installation(24%), insufficiency of after services(19%), often disorder(16%), unskillful management of soft ware(15%), insufficient ICT efficiency(13%) and unsatisfying of income increase(12%). The parts of problem occurred in ICT plastic greenhouse are the structure, actuator, environmental control system and sensor(approximate 14%, respectively), remote control technique(13%), plant management technique(12%), energy saving technique(10%) and utilization of software(8%). In the condition of lateral window closed, the average wind speed changed to slow, but it was faster in the condition of leeward side window opened than in the condition of lee and winward side window opened. The air movement in the condition of lateral window closed occur by air moving fan not by out air. It is not affect the room temperature but effective the uniformity of room temperature. The average temperature of low height greenhouse was uniform than high height one. The average temperature in condition of 3rd curtain opened become same with outside temperature after 2 hours, but take more 5 hours in condition of 3rd curtain closed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.100-112
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• 2005

Soil temperature was measured from the surface to 40 cm depth at three stations with different heights in tidal flat of Gomso Bay, west coast of Korea, for one month in every season 2004 to examine the thermal structure and the variation. Mean temperature in surface layer was higher in summer and lower in winter than in lower layer, reflecting the seasonal variation of vertically propagating structure of temperature by heating and cooling from the tidal flat surface. Standard deviation of temperature decreased from the surface to lower layer. Periodic variations of solar radiation energy and tide mainly caused short term variation of soil temperature, which was also intermittently influenced by precipitation and wind. Time series analysis showed the power spectral energy peaks at the periods of 24, 12 and 8 hours, and the strongest peak appeared at 24 hour period. These peaks can be interpreted as temperature waves forced by variations of solar radiation, diurnal tide and interaction of both variations, respectively. EOF analysis showed that the first and the second modes resolved 96% of variation of vertical temperature structure. The first mode was interpreted as the heating antl cooling from tidal flat surface and the second mode as the effect of phase lag produced by temperature wave propagation in the soil. The phase of heat transfer by 24 hour period wave, analyzed by cross spectrum, showed that mean phase difference of the temperature wave increased almost linearly with the soil depth. The time lags by the phase difference from surface to 10, 20 and 40cm were 3.2,6.5 and 9.8 hours, respectively. Vertical thermal diffusivity of temperature wave of 24 hour period was estimated using one dimensional thermal diffusion model. Average diffusivity over the soil depths and seasons resulted in $0.70{\times}10^{-6}m^2/s$ at the middle station and $0.57{\times}10^{-6}m^2/s$ at the lowest station. The depth-averaged diffusivity was large in spring and small in summer and the seasonal mean diffusivity vertically increased from 2 cm to 10 cm and decreased from 10 cm to 40 cm. Thermal propagation speeds were estimated by $8.75{\times}10^{-4}cm/s,\;3.8{\times}10{-4}cm/s,\;and\;1.7{\times}10^{-4}cm/s$ from 2 cm to 10 cm, 20 cm and 40 cm, respectively, indicating the speed reduction with depth increasing from the surface.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.703-710
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• 2010

In this study, a tactile stimulator was developed to resolve some problems from the previous version of the system such as system configuration, inappropriate stimulation control and additional problems. The developed tactile stimulator consists of control unit, drive unit and vibrator unit. The control unit was controlled by E-Prime software to generate appropriate vibration pulses. The drive unit supplies enough energy to the vibrator to generate effective stimulation pulses. The vibrator unit consists of small coin type vibrator and velcro, and was made to be attached at the hand easily. The developed tactile stimulator was designed by small-size, light-weight, low-power, simple-fabrication, max 35 channels and little delay time from instruction signal of E-Prime software to vibrator. The duration and magnitude of stimulation was controlled by 10 grades and the problems concerning stimulation control were compensated by wideband frequency ranges. Additionally, the electrical safety was ensured by low voltage operation. Vibrator was made to be attached on finger as well as on any part of the subject. Since this tactile stimulator is developed based on E-Prime software which is widely used in cognitive science, it is believed that this stimulator be suitable for the wide application of cognitive science study.

• Journal of Radiation Protection and Research
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• v.35 no.3
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• pp.111-116
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• 2010

Ionizing radiation is most widely used for X-Ray examination among all artificial radiation exposure, it takes up the largest proportion. Even in Korea, the medical exposure by diagnostic X-Ray examination takes up 17.4% of all radiation exposure. It takes up 92% even in artificial radiation exposure. There were 111,567 cases X-Ray radiography for skull diagnosis in 2007, which is 3% annual increase since 2004. Thus, It is need to establish the diagnostic reference level and the medical facilities as a diagnostic reference level to optimize radiation protection of the patients and to reduce the doses of X-ray. In this paper, we survey patient dose on skull radiography - collected from 114 medical facilities nationwide by using human phantom and glass dosimeter. When the patient dose for the skull radiography was measured and evaluated to establish the diagnostic reference level, 2.23 mGy was established for posterior-anterior imaging and 1.87 mGy for lateral imaging was established. The posterior-anterior skull radiography entrance surface dose of 2.23 is less than the guidance level of 5 mGy from the global organizations such as World Health Organization (WHO) and International Atomic Energy Agency (IAEA), and 1.87 mGy for the lateral skull imaging is less than the guidance level of 3 mGy, which is guided by the global organizations such as World Health Organization (WHO) and International Atomic Energy Agency (IAEA).

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.51-63
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• 2015

In order to investigation long-term variations of water qualities in the Saemangeum Salt-Water Lake formed after the sea-dike construction, the survey has carried out over 40 time from 2002 to 2010. The decreased salinity in surface water immediately after the dike construction has maintained on equal terms for years. After the dike construction, the early concentration of SPM in surface water has decreased but then it showed the tendency to move up and down due to the changes of water level in the lake. The elevated concentration of Chl-a in surface water initially after the dike construction was kept at the same conditions for years. The concentration of DIN in surface water has not changed before and shortly after the dike construction. However, the concentration of $NH_4-N$ in surface water has increased steadily after the dike construction. Consequently the concentration of DIN in the lake water after years has raised compared to pre-dike construction. The reduced concentration of DIP in surface water soon after the dike construction has increased after years as well as $NH_4-N$ due to the accumulation of organic matter to inside lake. Unlike with the unvaried $NO_3-N$, the concentration of DISi in surface water after the dike construction has immediately increased and maintained the enhanced level indicating the supply from other sources except the freshwater. Since the dike construction, the spatial characteristics of water quality was divided river sides and rest of the lake markedly. Stratification of river sides was more strong than the dike sides. In the warm seasons, hypoxia causing the release of nutrients and metals from sediment was observed downward about 1 m from surface of river sides. We strongly suggest to make some urgent measure to prevent low dissolved oxygen condition in the bottom layer of the river sides.