• Investigative Magnetic Resonance Imaging
• /
• v.9 no.1
• /
• pp.9-15
• /
• 2005

Purpose : This study attempted to investigate the effects of supply of highly concentrated $(30\%)$ oxygen on human ability of visuospatial cognition using time course data analysis of functional Magnetic Resonance Imaging (fMRI). Materials and Methods : To select an item set in the visuospatial performance test, two questionnaires with similar difficulty were developed through group testing. A group test was administered to 263 college students. Two types of questionnaire containing 20 questions were developed to measure the ability of visuospatial cognition. Eight college students (right-handed male, average age of 23.5 yrs) were examined for fMRI study. The experiment consisted of two runs of the visuospatial cognition testing, one with $21\%$ level of oxygen and the other with $30\%$ oxygen level. Each run consisted of 4 blocks, each containing control and visuospatial items. Functional brain images were taken from 37 MRI using the single-shot EPI method. Using the subtraction procedure, activated areas in the brain during visuospatial tasks were color-coded by t-score. To investigate the time course data in each activated area from brain images, 4 typical regions (cerebellum, occipital lobe, parietal lobe, and frontal lobe) were selected. Results : The average accuracy was $50.63{\pm}8.63$ and $62.50{\pm}9.64$ for $21\%\;and\;30\%$ oxygen respectively, and a statistically significant difference was found in the accuracy between the two types of oxygen (p<0.05). There were more activation areas observed at the cerebellum, occipital lobe, parietal lobe and frontal lobe with $30\%$ oxygen administration. The rate of increase in the cerebellum, occipital lobe and parietal lobe was $17\%$ and that of the frontal lobe, $50\%$. Especially, there were increase of intensity of BOLD signal at the parietal lobe with $30\%$ oxygen administration. The increase rate of the left parietal lobe was $1.4\%$ and that of the right parietal lobe, $1.7\%$. Conclusion : It is concluded that while performing visuospatial tasks, high concentrations of oxygen administration make oxygen administration sufficient, thus making neural network activate more, and the ability to perform visuospatial tasks increase.

• Journal of Wetlands Research
• /
• v.19 no.2
• /
• pp.252-258
• /
• 2017

To determine the effects of small dam on benthic macro-invertebrate community, benthic macro-invertebrates were surveyed with both quantitative and qualitative collecting methods from 4 sites at a terraced interval (3.02 small dams per 100 m) and from 5 sites at a non-terraced interval (0.96 small dams per 100 m) in upper reach of Dorim stream, Seoul. The average water flow rate was higher at the non-terraced interval (0.149 m/s) than at the terraced interval (0.043 m/s). Diptera, which prefer slow water flow or lentic habitats, appeared more abundantly in the terraced interval (78.3%) than in the non-terraced interval (32.0%)(p<.05). Ephemeroptera, which prefer fast water flow or lotic habitats, appeared more abundantly in the non-terraced interval (14.1%) than in the terraced interval (4.5%)(p=.203). There was a difference in species distribution of Trichoptera in terraced and non-terraced intervals depending on preferred environment. In the terraced interval, the occupancy ratio of gathering-collector was 1.8 times higher than in the non-terraced interval (p<.05). In contrast, filtering-collector appeared to be about 4.4 times higher rate in the terraced interval (p=.124). The evenness indexes (J′) were found to be 0.41 and 0.77, respectively in terraced area and non-terraced intervals. KSI, evaluating biological water quality, showed an average of 4.0 and 2.4 respectively in terraced and non-terraced intervals. EPT/C index, indicating the balance of the community, showed an average of 0.1 and 0.7 respectively in terraced and non-terraced intervals. It suggests that we should make small dams in order to maintain biodiversity of benthic macro-invertebrates.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.6
• /
• pp.766-773
• /
• 2012

This study investigates the effects of diets with mulberry leaf and Cudrania tricuspidata leaf supplements on blood glucose-related biomarkers in streptozotocin-induced diabetic rats. Male diabetic Sprague-Dawley rats were divided into groups and fed several diets. Group A was fed a diet with a 10% supplement of mulberry leaves. Group B was fed a diet with a 10% supplement of mulberry leaves and an additional 10% supplement of Cudrania tricuspidata leaves. Group C was fed a diet with a 10% supplement of mulberry leaves and an additional 30% supplement of Cudrania tricuspidata leaves. Group D was fed a diet with a 10% supplement of Cudrania tricuspidata leaves. Group E was the DM control. All diets were based on AIN-93G diet and they all lasted 6 weeks. The blood glucose levels of groups B and C stayed similar to initial levels (reference blood glucose) for the experimental period, which was significantly lower than levels in groups A, D, and E at the 6th week (p<0.05). And the area under the blood glucose curve (AUC) was also significantly lower in groups B and C than in groups D and E (p<0.05). The fasting blood glucose level after the experiment was significantly lower in groups B and C (p<0.05), and the C-peptide content of group C was as high as 50 pmol/L on average. The HbA1c content was also significantly lower in groups A and B than in group E (p<0.05). The serum TG, AST, and ALT levels were significantly decreased in groups A, B, and D than in group E (p<0.05). From the findings, it is shown that a diet of 1:1 mulberry and Cudrania tricuspidata leaf supplements could improve blood glucose-related biomarkers.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.1 no.1
• /
• pp.17-25
• /
• 2013

Thermal storage technology used for indoor heating and cooling to maintain a constant temperature for a long period of time has an advantage of raising energy use efficiency. This, the phase changing material, which utilizes heat storage properties of the substances, capsulizes substances that melt at a constant temperature. This is applied to construction materials to block or save energy due to heat storage and heat protection during the process in which substances melt or freeze according to the indoor or outdoor temperature. The micro-encapsulation method is used to create thermal storage from phase changing material. This method can be broadly classified in 3 ways: chemical method, physical and chemical method and physical and mechanical method. In the physical and chemical method, a wet process using the micro-encapsulation process utilized. This process emulsifies the core material in a solvent then coats the monomer polymer on the wall of the emulsion to harden it. In this process, a surfactant is utilized to enhance the performance of the emulsion of the core material and the coating of the wall monomer. The performance of the micro-encapsulation, especially the coating thickness of the wall material and the uniformity of the coating, is largely dependent on the characteristics of the surfactant. This research compares the performance of the micro-capsules and heat storage for product according to molecular mass and concentration of the surfactant, SSMA (sulfonated styrene-maleic anhydride), when it comes to micro-encapsulation through interfacial polymerization, in which Dodecan-1 is transformed to melamin resin, a heat storage material using phase changing properties. In addition, the thickness of the micro-encapsulation wall material and residual melamine were reduced by adjusting the concentration of melamin resin microcapsules.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.2
• /
• pp.192-198
• /
• 2006

Treatment effects of grape fruit stem extracts (GFSE) containing trans-resveratrol on the storage property of fresh jujube (Zizyphus jujube) were investigated. Fresh jujubes were packed in different storage containers [polyethylene terephthalate (PET) and polyethylene (PE)], and treated with GFSE containing trans-resveratrol of 10, 30 and 50 ppm, respectively. The storage vessels filled with $N_2$ gas, and stored in refrigerator $(0{\pm}1^{\circ}C)$ during 18 weeks, and then quality characteristics during storage period were analysed. Ethylene gas increased until 8 weeks and decreased afterward. Decaying of jujube started at $6\~8$ weeks in control, but it did at 14 week storage for the fruits at $50\%$ maturity treated with 10 ppm of GFSE and packed in PE vessel. Soluble solid (Brix degree) and total acidity of fresh jujube slightly increased in all the treatments during storage period. Hardness slightly increased until 4 weeks and decreased afterward. Vitamin C content was at the highest content of $86.8\~273.4$ mg/100g for most of treatments at 2 weeks and decreased afterward. Storage stability was higher for $50\%$ maturity fruits than for the $70\%$ maturity, and higher for PE vessels than PET containers. Storage period of fresh jujube in this experiment ranges in $10\~12$ weeks for $50\%$ maturity fruits treated with 10 ppm of GFSE and packed in PE vessel.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.10
• /
• pp.1559-1565
• /
• 2005

The Purpose of this study was to investigate college students' attitude toward body weight control, health-related lifestyle and dietary behavior by their perception on body image and obesity index. The subjects were 871 nation- wide college students (330 male and 541 female students) participating in a nutritional education program via internet- A cross-sectional survey was conducted using a self-administered questionnaire via internet. The data were analyzed by a SPSS 10.0 program. Height and weight (p < 0.05), and the distribution of obesity index (p < 0.001) showed significant differences between male and female college students. As for self perception on body image, the necessity of body weight control and the experience of efforts to change the body weight, there were significant differences between male and female college students (p < 0.001). There were significant differences among groups by obesity index in the hours of exercise (p < 0.01), drinking (p < 0.01) and smoking (P < 0.001). As for methods of body weight control, all the groups by obesity index thought that program of body weight control by diet company is the most desirable method. Therefore, we must recognize that it is hard to correct health problems resulting from wrong lifestyle and dietary behavior fixed during college life and prepare a system for college students to obtain correct lifestyle and dietary behavior.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.791-800
• /
• 2006

This study examined the effects of gromwell (Lithospermum erythrorhizon) extracts on the storage characteristics of Kangjung. At an increase of $0{\sim}0.25%$, there was no significant difference in the moisture content of wild and cultivated gromwell extract added to Kangjung, whereas there was a significant difference when increased to 0.5%. When compared, the occurrence of lipid oxidation among the controlled gromwell extract group stored at $60^{\circ}C$, resulted in peroxide values exceeding 40 meq/kg which is a maximum value for Hankwa within 12 hours of storage. However, at an increase of 0.25%, the cultivated gromwell extract added group reached limits within 16 hours. Furthermore, at a 0.5% increase in cultivated gromwell and 0.25% in wild gromwell, extract added groups exceeded this limit within 20 hours of storage. Gromwell added Kangjung, a fried food, showed efficiency in suppressing oxidation of fat, more so in the wild gromwell than the cultivated gromwell. In addition, efficiency in suppressing oxidation of fat increased at the 0.5% level than the 0.25% level. In conclusion, it is believed that an unused pigment resource called Lithospermum erythrorhizon, normally reserved for medicinal use, can be distributed as a safe food additive. In addition, as Lithospermum erythrorhizon is a natural antioxidant in fried foods, we believe this satisfies the demand for natural food.

• Journal of Korean Society of Forest Science
• /
• v.55 no.1
• /
• pp.68-75
• /
• 1982

This study was carried out to promote percent survival of the walnut seedling grafting. The hardwood scions of the walnut were grafted on the nures seed-stock of the Juglans mandshurica Mat in an electric heating bed, then planted in field. The results obtained from the study were as follows : The optimum time of scion cpllection was from January to February. The best medium of the seed bed was sandy soil. The best grafting time was form the early to the 20the of the march. When the grafted seedling in the heating bed was trans-planted on filed 90percent of the seedlings was survived until autmn. The percent grafting on the elective heating bed was 90%. Crown gall occuring frequently in chestnut nurse graft was not appeared in juglans mandshurica Max grafted seedling of after outplanting. The grafted seedlings have not shown any physiological defects but developed normaly 3 years since grafting.

• Environmental and Resource Economics Review
• /
• v.14 no.2
• /
• pp.519-547
• /
• 2005

The aim of this study is to analysis how economic welfare lost happens within the present korea seasonal and time period electricity pricing system and find out reasonable electricity price system acceptable during the transitional period of korea electricity industry restructuring To analyze economic welfare lost in the electricity industry, in advance seasonal and time periodic 9 demand curves(summer, spring ＆fall, winter/peak-load time, middle-load time, low-load time) and one market supply curve are made and then using these demand and supply curve, seasonal and time periodic market equilibrium prices is calculated. Finally, comparing these market equilibrium prices with present regulated classified seasonal and time periodic prices, the whole economic welfare lost in the electricity industry is calculated. The result of this study shows that in 2002, the total economic welfare lost in electricity industry is 137,770 million Won and under present price system, the worst welfare lost is happening seasonally in spring ＆ fall, time periodically in the middle-load time. Specifically analyzing the characteristics of welfare lost, especially on the industry customers and service customers which are applied in seasonal and time periodic pricing, for the industry customers, the welfare lost calculated in this class occupies 51% of the total welfare lost in the whole electricity industry and the worst welfare lost is happening seasonally in spring ＆ fall, time periodically in the middle-load time. For service customers, the welfare lost calculated in this class occupies 13% of the total welfare lost in the whole electricity industry and the worst welfare lost is happening seasonally in summer, time periodically in the peak time Finally, this study was made based on the year of 2002 and KEPCO has practiced two times of rate change until now. The result of rate change was positively analyzed in the direction of economic welfare improvement(welfare improvement achieved by 16.3% compared to 2002 result).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.4
• /
• pp.339-349
• /
• 2010

The uses of the polypropylene bulk bags having the loading capacities more than 500 kg are increasing in Korea recently as a storage container for rough rice. This study was performed to obtain the basic information on the changes of temperature and relative humidity in the bulk-bag-stored high moisture rough rice during waiting for drying. At the moisture content more than 22% on wet weight basis of paddy, the bulk-bag inside temperature rose up to more than $40^{\circ}C$ and then slid down during storage. For example, in case of Hwaseongbyeo, 26.5% moisture content of rough rice (MCRR) harvested at 46 days after heading (DAH) showed $54.5^{\circ}C$ of peak temperature at 66.8 hours after bulk-bag loading, 22.5% MCRR harvested at 52 DAH exhibited $42.0^{\circ}C$ at 81.1 hours, and 19.7% MCRR harvested at 55 DAH displayed $38.9^{\circ}C$ at 119.0 hours. There were a good linear relationship between peak temperatures of bulk-bag inside and moisture contents of paddy ($r^2$=0.89 in 2005, and 0.87 in 2006), while the slope and intercept of the linear regression equation was affected by the environmental conditions such as ambient temperatures and microbial flora. The peak temperatures increased with the rate of about $2.74-3.33^{\circ}C$ per every 1% increase of moisture content at higher moisture contents of paddy than 19%. The relative humidity varied depending on bulk-bag inside temperature and rough rice moisture content, and showed the range of 94.2% to 99.9% in the central point of the bulk-bag. The results suggested that a rapid drying treatment as soon as possible was needed to produce a good quality of rice when the paddy of high moisture more than 22% on wet basis was harvested in a bulk-bag especially at high ambient temperature.