• Journal of Radiation Protection and Research
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• v.24 no.4
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• pp.195-203
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• 1999

It is difficult to determine dosimetric characteristics for small field photon beams since such small fields do not achieve complete lateral electronic equilibrium and have steep dose gradients. Dosimetric characteristics of small field 4, 6, and 10 MeV photon beams have been measured in water with a diamond detector and compared to measurements using small volume cylindrical and plane parallel ionization chambers. Percent depth dose (PDD) and beam profiles for 6 and 10 MeV photon beams were measured with diamond detector and cylindrical ion chamber for small fields ranging from $1{\times}1\;to\;4{\times}4cm^2$. Total scatter factors($S_{c,p}$) for 4, 6, and 10 MeV photon beams were measured with diamond detector, cylindrical and plane parallel ion chambers for small fields ranging from $1{\times}1\;to\;4{\times}4cm^2$. The $S_{c,p}$ factors obtained with three detectors for 4, 6, and 10 MeV photon beams agreed well ($\pm1.2%$) for field sizes greater than $2{\times}2,\;2.5{\times}2.5,\;and\;3{\times}3\;cm^2$, respectively. For smaller field sizes, the cylindrical and plane parallel ionization chambers measure a smaller $S_{c,p}$ factor, as a result of the steep dose gradients across their sensitive volumes. The PDD values obtained with diamond detector and cylindrical ionization chamber for 6 and 10MeV photon beams agreed well ($\pm1.5%$) for field sizes greater than $4{\times}4\;cm^2$. For smaller field sizes, diamond detector produced a depth-dose curve which had a significantly shallower falloff than that obtained from the measurements of relative depth-dose with a cylindrical ionization chamber. For the measurements of beam profiles, a distortion in terms of broadened penumbra was observed with a cylindrical ionization chamber since diamond detector exhibited higher spatial resolution. The diamond detector with small sensitive volume, near water equivalent, and high spatial resolution is suitable detector compared to ionization chambers for the measurements of small field photon beams.

• Journal of Aquaculture
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• v.15 no.3
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• pp.145-155
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• 2002

Effect of density (30, 40, 65, 90 or 120/cage) of lantern and bottom cages on growth of the ark shell, Scapharca satowi was studied in the Korean west coast from April 2000 to October 2001, when the following range of environmental conditions prevailed : temperature : 4.2 -25.5 $^{\circ}C, salinity : 30.23-32.$15\textperthousand, dissolved oxygen : 5.12-7.16 $ml$/l, pH : 7.84-8.17, phosphate : 0.22-0.56 $\mu $M, dissolved inorganic nitrogen : 3.16-9.10 $\mu $M, suspended solid : 7.6-17.9 mg/l, chemical oxygen demand: 0.46-1.61 mg/l and chlorophyll-a : 0.92-5.93 $\mug/l. Daily growth rate of shell length ranged from 0.066 to 0.071 mm/day for the lantern net cages, and from 0.079 to 0.082 mm/day for the bottom cages. Total weight also ranged from 0.067 to 0.082 g/day in the lantern net cages, as against 0.099 to 0.114 g/day in the bottom cages. Hemoglobin content of S. satowi (55 mm shell length), which was about 3.9 g/dl during february, 2001, increased to 6.0 and 7.0 g/dl during October, 2001 in animals culture in the lantern and bottom cages, respectively. ANOVA test of the growth rate showed that the growth rate of S. satowi, was significantly dependent on rearing density and the tested culture methods (P < 0.0001). The daily growth rate of the shell length was more significantly correlated with water temperature; the growth rate of shell length and total weight showed a tendency decrease with decreasing temperature. In cages suspended at the bottom, not only the increase shell weight but also the meat obtainable from comparable sized S. satowi was greater. Survival decreased with increasing density and was optimal at the density of 30 individual/cage.

• Progress in Medical Physics
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• v.16 no.4
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• pp.166-175
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• 2005

The purpose of this study is to develop the optimization method for adjusting the film isocenter shift and to suggest the quantitative acceptable criteria for film dosimetry after optimization In the dynamic conformal arc radiation therapy (DCAR). The DCAR planning was peformed In 7 patients with brain metastasis. Both absolute dosimetry with ion chamber and relative film dosimetry were peformed throughout the DCAR using BrainLab's micro-multileaf collimator. An optimization method for obtaining the global minimum was used to adjust for the error in the film isocenter shift, which is the largest pan of systemic errors. The mean of point dose difference between measured value using ion chamber and calculated value acquired from planning system was $0.51{\pm}0.43\%$ and maximum was $1.14\%$ with absolute dosimetry These results were within the AAPM criteria of below $5\%$. The translation values of film isocenter shift with optimization were within ${\pm}$1 mm in all patients. The mean of average dose difference before and after optimization was $1.70{\pm}0.35\%$ and $1.34{\pm}0.20\%$, respectively, and the mean ratios over $5\%$ dose difference was $4.54{\pm}3.94\%$ and $0.11{\pm}0.12\%$, respectively. After optimization, the dose differences decreased dramatically and a ratio over $5\%$ dose difference and average dose difference was less than $2\%$. This optimization method is effective in adjusting the error of the film isocenter shift, which Is the largest part of systemic errors, and the results of this research suggested the quantitative acceptable criteria could be accurate and useful in clinical application of dosimetric verification using film dosimetry as follows; film isocenter shift with optimization should be within ${\pm}$1 mm, and a ratio over $5\%$ dose difference and average dose difference were less than $2\%$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1065-1070
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• 2002

The purpose of this study was investigated the effects of YK-209 mulberry leaves on antioxidative defense system of liver in diabetic rats induced with streptozotocin (STZ). Male Sprague-Dawley rats weighing 100$\pm$10 g were randomly assigned to one normal and four STZ-induced diabetic groups; YK-209 mulberry leaves free diet (DM group),0.1% YK-209 mulberry leaves diet (DM-0.1Y group),0.2% YK-209 mulberry leaves diet (DM-0.2Y group) and 0.4% YK-209 mulberry leaves diet (DM-0.4Y group). Diabetes was induced by intravenous Injection of 55 mg/kg body weight of STZ in sodium citrate buffer (pH 4.3) via tail vein after 4 weeks feeding of experimental diets. Rats were sacrificed at the 9th day of diabetic states. Liver weight in all four diabetic groups were higher than normal group, but YK-209 mulberry supplementation groups were lower than DM group. Hepatic superoxide dismutase (SOD) activity was significantly decreased in all diabetic groups, compared with normal group. Hepatic glutathione peroxidase (GSHpx) activity was 7.3% decreased in DM group, compared with normal group, but those of DM-0.1Y and DM-0.2Y groups were maintained the normal level. The hepatic thiobarbituric acid reactive substances was markedly increased by 144% in DM group, compared with normal group, but those of DM-0. 1Y, DM-0.2Y groups were maintained the normal level. The contents of lipofuscin in liver were increased by 100% in DM group compared with normal group, but those of DM-0. 1Y, DM-0.2Y and DM-0.4Y groups were decreased to 42% 43% and 44%, respectively, compared with DM group. The hepatic superoxide radical (0$^2$-) contents in DM group were increased to 81%, compared with normal group, but those of DM-0.1Y and DM-0.4Y groups were similar to those of normal group. The present result indicate that YK-209 mulberry leaves regarded to suppress lipid peroxidation as an free radical scavenger system by the inhibition of oxidative stress.

• Journal of Korean Medical classics
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• v.4
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• pp.101-126
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• 1990

At early Cheong (淸) dynasty, in medical aspect by dependent on practical studying attitude that must found a theory only by an evidence, there had been a tendancy that hoped direct research of sages' mind-eye by escaping the theory of individual classes since Geum-Won (金-元) dynasty. Yoo Chang (喩昌), born in Man-Ryeok (萬曆) 12th year of Myung (明) dynasty (A.D.1583) and dead in Gang-Hee (康熙) 3rd year of Cheong (淸) dynasty (A.D.1664). The results were as follows after studying his practical idea of medicine. 1. Yoo Chang, by recognizing the ${\ll}$Sang-Han-Ro${\gg}$ has lost its true meaning after commented by Wang Hee (王熙), Lim Eog (林億), Seong Moo-I (成無巳), etc. according to Bang Yoo-Jip's (方有執) Chak-Gan-Jung-Jeong (錯簡重訂) theory, he diversified the protocal of ${\ll}$Sang-Han-Ro${\gg}$ 397 method and arranged under Six Meridian part. (六經) 2. The theory of Sam-Gang-Jeong-Rip (三綱鼎立) can be summerized Gye-Ji (桂枝) syndrome which is the case of Wind (風) has injured Wi (衛) stage, Ma-hwang (麻黃) syndrome which is the case of Cold (寒) has injured Yeong (榮) stage, Dae-Cheong-Ryong (大靑龍) syndrome which is the case both of Wind-Cold (風寒) has injured Yeong-Wi (榮衛) stage, and there has been Sam-Gang-Jeong-Rip theory by anterior medical practitioners already but the person who formally used its Sam-Gang-Jeong-Rip term is Yoo Chang. 3. Yoo Chang seized the On Byeng (溫病) by dividing three category and in Byon-Jeung-Si-Chi (辨證施治) he influenced to many aspect of establishment of later Byon-Jeung system On-Byong (溫病의 辨證體系) pertaining to Triple-Warmer by O-Dang (吳瑭) introducing Triple-Wanner Theory. (三焦理論) 4. At Chu-Jo-Ron (秋燥論) of ${\ll}$EUi-Moon-Beop-Ryo${\gg}$, while ${\ll}$Nae-Gyeong${\gg}$ describing if humidity injury Lung, then occur a disorder in it, Yoo Chang recognized that of au tuam when dryness injure Lung there occure a disorder is it so he insisted that at this case, must use Cheong-Joe-Goo-Pye method (淸操救肺法) withherbs, pertaing to Gam-Yoo-Ja-Yoon(甘柔滋潤性) property and he invented Cheong-Joe-Goo-Pye-Tang. (淸操救肺湯) 5. Yoo Chang', so called, Dae-Gi (大氣) indicates Yang-Gi (陽氣) of chest, he insisted that man's creation and every physiological activity depends on maintainence of Dae-Gi, and it integrate Yeong-Gi (榮氣), Wea-Gi (衛氣), Jong-Gi (宗氣), Jang-Boo-Ji-Gi (臟腑之氣), Gyeong-Rak-Ji-Gi. (經絡之氣) 6. Yoo Chang's expression about partical function and character of stomach, not only bolster its theory of historical physician's expression, that is stomach is. foundatness of postnatal period, but also it has corresponding aspect with modern medicine and clinic. 7. Yoo Chang emphasized "if one cure a disease, be must understood the character of disease first and use drugs later" (先議病 後用藥) phrase about of drug usage, and his theory of Geup-Rew-Man-Joo method (急流挽舟) and three therapy of Simple Ascite (單腹腸) are all unique opinion based upon this phrase mentioned above. 8. Yoo Chang's practical idea of medicine greatly influenced to Jang Ro (張璐), Hwang Won-A (黃元御), Oh Eui-Rak (吳儀洛), Joo Yang-Joon (周揚俊), etc. and theory of Sam-Gang-Jeng-Rip (三綱鼎立), Triple Warmer Theory of On Byong (溫疫의 三焦論治), Chu-Jo-Ron (秋燥論), Dae-Gi-Ron (大氣論) etc. became important object to student of Sang-Han (傷寒) and On-Byeng. (溫病) 9. Yoo Chang's Writings has more practical meaning than other physician's, especially, later the idea of Sang-Han (傷寒) and On-Byong (溫病) greatly contributed to development of Sang-Han theory and formation of On-Byong theory.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.79-87
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• 2012

This research was conducted to obtain basic data with regard to the heating performance that would be produced by installing an aluminum hot water pipe inside the greenhouse with the goal of reducing the heating energy in greenhouse. The research results are summarized as follows. The degree of difference in relation to the temperature by height within the greenhouse during the entire experiment was significant - within the range of 4.0~$7.0^{\circ}C$. The temperature difference between incoming and outgoing water was about $3.3^{\circ}C$ greater when FCU was activated compared to when it was not activated. Meanwhile, the amount of energy consumed increased about 36.2~40.1%. The amount of pyrexia per hour also increased by 44.6~52.0%. During the experiment period, circulated flux was within the range of 0.48~$0.49L{\cdot}s^{-1}$ while average fluid speed was 1.53~$1.56m{\cdot}s^{-1}$. The average temperature difference between incoming and outgoing water was 6.24~$11.50^{\circ}C$. The amount of heating value by each set temperature within the minimum outdoor temperature range of -14.0~$-0.6^{\circ}C$ was 135,930~307,150 kcal, and the range was within the 9,610~$19,630kcal{\cdot}h^{-1}$ per hour. This demonstrated that about 23~53% heating energy of the maximum heating load could be supplied. Total radiating value and amount of energy consumed were 2,548,306 kcal and 3,075.7 kWh, respectively. When heating takes place using oil, which is a fossil fuel, the total amount of light oil consumed was 281.6 L while the cost was 321,000 won. When the electricity cost for farms is applied, the total cost was about 110,730 won, which is about 33.5% of the cost required compared to oil consumption. The temperature at in the experiment area was about 8.3~$14.6^{\circ}C$ higher compared to that of the control area.

• Membrane Journal
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• v.24 no.3
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• pp.213-222
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• 2014

In this study, 2-stage recirculation membrane process was developed for purification of high purity bio-methane for the vehicle fuel application. Pure gas permeation and mixture gas permeation test were done as a function of methane content and pressure in the feed using polysulfone membrane modules. 2-stage membrane plant was designed, constructed in a food waste treatment cite. Dehumidification, dry desulfurization, and desiloxane plants are installed for the removal of $H_2O$, $H_2S$ and siloxane in the biogas. Permeation test were done with the pre-treated methane mixture in terms of methane purity and recovery by adjusting the ratio of membrane area (1:1, 1:3, 2:2) in the first and second membrane modules in the plant. When membrane area of 2 stage increased to $3m^2$ from $1m^2$ at 1-stage membrane area of $1m^2$, the feed rate and $CH_4$ recovery at 95% methane purity were increased from 47.1% to 92.5% respectively. When the membrane area increased two-fold (1:1 to 2:2), $CH_4$ recovery increased from 47.1% to 88.3%. When the feed flow rate was increased, in 1:3 ratio, final purity of the methane is reduced, the methane recovery is increased. When operating pressure was increased, the feed rate was increased and recovery was slightly decreased. From this result, membrane area, feed pressure and feed rate could be the important factor to the performance of the membrane process.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.119-125
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• 2009

To understand the ecological function of heterotrophic bacterial community in water column of large freshwater lakes in the permafrost zone, we investigated the structure and function of bacterial community in Lake Khuvsgul, Mongolia. Species composition of overall bacterial community was analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments, and bacteria that can be cultured at 10oC were isolated and characterized. Based on the depth profile of environmental parameters, thermocline and chemocline were recognized at the 5~10 m zone of the water column. The stratified DGGE profile indicated that the discontinuity of water properties might influence the structure of bacterial community: band profiles in the 0~5 m zone were diverse with large change by depth, but the profile was relatively stable at the $\geq$10 m zone, with predominance of the band identified as Acidovorax facilis. Bacterial cultures were screened for protease, cellulase, amylase and lipase activity, and 23 isolates were selected for high activity of the hydrolytic enzymes. The isolates were identified based on their 16S rRNA gene sequences. In the surface water (zero meter depth), Acidovorax defluvii and Sphingobacterium faecium with high cellulase activity were present. Flavobacterium succinicans, Mycoplana bullata and A. facilis were stably predominant isolates at 2 m, 5 m, and $\geq$10 m depths, respectively. F. succinicans isolates showed high protease activity while M. bullata isolates showed moderate levels of protease and celluase activity. A. facilis isolates showed either cellulase or lipase activity, exclusively to each other. According to the profile of growth rates of the isolates in the temperature range of $0\sim42^{\circ}C$, the surface-zone (0~5 m) isolates were facultative psychrophiles while isolates from $\geq$10 m depth were typical mesophiles. This stratification is believed to be due to stratified availability of organic materials to the bacterial decomposers. In the water column below the chemoline, the environment is extremely oligotrophic so that the trait of rapid growth in low temperature might not be demanded by deep-lake decomposers. The stratified distribution of community composition and decomposer activity in Lake Khuvsgul implies that ecological functions of bacterial community in lakes of cold region are sharply divided by water column stratification.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.139-144
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• 2006

In this study, we investigated the antioxidant activity of solvent extracts from Sargassum thunbergii by measuring electron-donating ability (EDA), nitrite- scavenging ability, superoxide dismutase (SOD)-like activity, reducing power and antioxidant activity in $\beta-carotene-linoleate$ model system. Total phenolic compound contents of chloroform and methanol extracts from Sargassum thunbergii were $22.5{\pm}0.8$ mg/100 mL and $20.1{\pm}0.6$ mg/100 mL, respectively. The EDA were proportionally increased with concentration of the extracts except hexane extract. The EDAs were $70.4\%\;and\;63.2\%$ in methanol and water at concentration of $1000{\mu}g/mL$, respectively. The nitrite-scavenging ability of methanol extract (pH 2.5, $1000{\mu}g/mL$) was $89.4{\pm}0.9\%$ that was higher than those of other extracts. SOD-like ability of chloroform extract was stronger than other extracts. Reducing power of chloroform extracts at $1000{\mu}g/mL$ were 0.75 as O.D. value of 700 nm and antioxidant activities measured with $\beta-carotene-linoleate$ model system were in order of methanol $(78.4\%)>BHT\;(72.1\%)>chloroform\;(62.2\%)>water\;(51.4\%)>hexane\;(43.2\%)$. These results indicated that methanol extract from Sargassum thunbergii showed the highest activities on the EDA, nitrate- scavenging ability and antioxidant activities while the chloroform extract had the highest effect on the SOD-like activity and reducing power.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.5
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• pp.492-501
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• 2007

Coastal disasters have become one of the most important issues in every coastal country. In Korea, coastal disasters such as storm surge, sea level rise and extreme weather have placed many coastal regions in danger of being exposed or damaged during subsequent storms and gradual shoreline retreat. A storm surge is an onshore gush of water associated with a tow pressure weather system, typically in typhoon season. However, it is very difficult to predict storm surge height and inundation due to the irregularity of the course and intensity of a typhoon. To provide a new scheme of typhoon damage prediction model, the scenario which changes the central pressure, the maximum wind radius, the track and the proceeding speed by corresponding previous typhoon database, was composed. The virtual typhoon scenario database was constructed with individual scenario simulation and evaluation, in which it extracted the result from the scenario database of information of the hereafter typhoon and information due to climate change. This virtual typhoon scenario database will apply damage prediction information about a typhoon. This study performed construction and analysis of the simulation system with the storm surge/coastal inundation model at Masan coastal areas, and applied method for predicting using the scenario of the storm surge.