• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.850-858
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• 1996

Green tea leaves 12.5 g were extracted twice with 500 ml boiling water. The green tea extract (GTE) contained 4.67 mg solid. The GTE contained polyphenols sush as 54.12% (-) epicatechin gallate, 26.21% (-) epicatechin, 10.71% epicatechin gallate, 7.09% (-) epicatechin and 1.85% catechin. The GTE inhibited the copper-catalyzed oxidation of human LDL at the concentrations of 50 and $100\;{\mu}g/ml$ GTE in the presence of $5\;{\mu}M$ $CuSO_{4}$. The electrophoretic mobility of the LDL oxidized in the presence of $5\;{\mu}M\;CuSO_{4}$ was higher than that of the native LDL. The GTE also inhibited LDL oxidation induced by J774, human monocyte-derived macrophages and vascular endotherial cells. The LDL modified by copper or cells was inhibited by human macrophages at a much greater rate than native LDL in the presence of GTE. The GTE was found to be a potent inhibitor of modification of LDL. GTE inhibited the uptake of cell-modified $^(125)I-labelled$ LDL by macrophages. The formation of conjugated dienes was strongly inhibited in the presence of 50 or $100\;{\mu}g/ml$ GTE.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.68-76
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• 1984

The study was conducted to investigate an optimum growing condition for various sizes of seedlings of rice for mechanical transplantation under different sowing rates, different levels of fertilizers, different sowing dates and g rowing days. The plant height, leaf number and dry weight of seedlings increased as the sowing rate decreased and amount of fertilizer applied were increased. Also those seedling characters increased as the rice planted late and the total growing periods increased. The factors affected seedling chracters were ordered as following-sowing times>growing days>sowing rate>fertilizer levels. 200 gr. of seeds per box and 4 gr. of fertilizers were optimum for young seedling growth, when sown early. For medium size of seed ling growth, 50 grams and 100 to 125 grams of rice seemed to be adequate for 25 days old and 35 days old seedling, respectively. However, the 45 days old seedling grew too mach and were not suitable for mechanical transplantation. When planted late, similar results were obtained with more differences among treatments. In other words, the suitable plant density was obtained when 100 gr. of seeds were planted per box. Middle class of seedlings were obtained when 100 to 150 gr. of rice were planted per box and grown for 25 days. The seedlings from the box with 100 to 150 gr. of rice per box were over grown and ratio of suitable seedling was also low if they were grown over 35 days.

• Journal of dental hygiene science
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• v.8 no.1
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• pp.35-42
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• 2008

This survey was compared and analyzed about the primary factor that dental office's working environment effect on physical subjective symptom and based on self-filling survey, 656 dental hygienists on July through August 2006, and analyzed using descriptive statics, ANOVA and Multiple Regression Analysis. The result of satisfaction degree of hospital working environment was pretty low about office air condition. Most people have complained that office's air quality makes it difficult to their work and mentioned that they were sore and dull all over the back, shoulder, and neck. The odor is major factor to be satisfied with office environment. Proper ventilates the way open the window more often was essential to maintain fresh indoor air quality and keep the extraction materials by separator and sealing tightly for remove the odor. Other factors were temperature, lighting fixture, ventilation facilities, and freshness of air. Dental hygienist was unsatisfied with hospital air condition and this polluted air condition was the cause of physical subjective symptom in work place. Furthermore, this research would be applied for improvement of working environment by decreasing of indoor air pollution.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.43-48
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• 1986

The experiment was conducted to know the varietal difference in changing aspect of daily filling sink during of rice using three cultivars; ‘Suweon 295’ (japonica), ‘Suwoen 264’ and ‘IR 1317-70-1’ (semi-dwarf indica) cultivated in the field and green house of the Crop Experiment Station in 1983. There was not significant varietal difference in flowering habit and duration of flowering period each panicle. Semi-dwarf indica cultivars showed shorter days to physiological maturity of rice kernel than the japonica one. The former also displayed earlier decrease in water content of rice grain during ripening than the latter. Japonica variety revealed larger difference in ripening advancement between vigorous florets and inferior one than semi-dwarf indica varieties. The semi-dwarf indica rice cultivars expressed significantly shrewder parabola of daily filling of sink per panicle during ripening than the japonica one. The time showing maximum capacity of daily filling of sink per panicle during ripening was 10-12 days after anthesis. The filling capacity of daily sink filling per panicle for 'IR 1317-70-1', 'Suweon 264' and 'Suweon 265' at this time were about 240 mg, 165 mg and 145 mg, respectively. Pattern of sink filling per panicle during ripening was slightly changed by the cultural environment. ‘Suweon 295’ showed slightly sharper parabola and 2-3 days earlier time showing maximum capcity of daily sink demand per panicle during ripening in the field than those in the green house.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1992.10a
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• pp.59-64
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• 1992

터빈 블레이드와 같이 회전하는 구조물의 파단은 공진 근처에서 진동이 발 생할 때에 이에 기인하는 피로에 의하여 발생한다. 그러므로 이와 같은 파단 을 피하기 위해서는 설계 단계에서 이론적인 계산에 의하여 구조물의 고유 진동수를 결정하는 것이 상당히 중요하다. 판이 회전을 받게 되면 원심력에 의하여 판의 강성이 증가하므로 고유진동수가 회전하지 않는 판의 고유진동 수보다는 상당히 증가하게 된다. 이에 대한 연구가 국내외에서 상당수 행하 여졌지만, 연구의 대부분이 회전의 영향을 고려하지 않은 정지판(stationary plate)에 대한 것이며 뢰전을 고려한 연구는 극히 제한되어 있다. 또한 회전 의 영향을 고려한 연구의 대부분이 해석 대상을 보로서 단순화 시켰고 해법 으로는 유한요소법과 Ritz법 등을 사용하였다. 이는 블레이드가 지니고 있는 기하학적인 형상과 진동 특성이 해석적인 방법으로 해결하는 데에는 상당한 어려움이 있기 때문이다. 실제적으로는 터빈 블레이드와 같은 회전체의 진동 특성이 설치각이나 비틀림각, 판의 형상비, 회전속도 등의 변화에 의하여 영 향을 받기 때문에 보와 같은 진동 거동을 보이기보다는 판이나 셀과 같은 진동 거동을 보이므로 보다 정확한 해석을 수행하기 위해서는 해석 대상을 판이나 셀로서 취급하는 것이 타당하다. 따라서 본 연구에서는 위와 같은 이 유 때문에 해석 대상을 등방성 사각판과 직교이방성 복합재료 사각판으로 선택하였으며, 구조물의 고유진동수에 영향을 미치는 다음과 같은 인자들을 해석에 고려하였다. 1. 회전속도 (rotational speed) 2. 설치각 (setting angle) 3. 허브의 반경 (hub radius) 4. 판의 형상비 (aspect ratio) 5. 적층순서 (stacking sequence)구조물에 대한 동적실험(dynamic test)을 통하여 단기간에 동적특성을 결정하고 SDM(structure dynamic modification)이나 FRS(force response simulation)를 수행하여 임의의 좌표 공간에 대한 진동수준을 해석적으로 예측할 뿐만 아니라 구조물의 진동제어 를 위한 동적인자를 변경시킬 수 있는 정보를 제공하며 장비를 방진할 경우 신뢰성 있는 전달률을 결정할 수 있다. 실험적으로 철교, 교량이나 건물의 철골구조 및 2층 바닥 등 대,중형의 복잡한 구조물에 대항 동특성을 나타내 는 모빌리티를 결정할 경우 충격 가진 실험이 사용되는 실험장비 측면에서 나 실험을 수행하는 과정이 대체적으로 간편하다. 그러나 이 경우 대상 구조 물을 충분히 가진시킬수 있는 용량의 대형 충격기(large impact hammer)가 필요하게 된다. 이러한 동적실험은 약 길이 61m, 폭 16m의 4경간 교량에 대 하여 동적실험을 수행하여 가능성을 확인하였다. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but stron

• Journal of Korean Society of Transportation
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• v.18 no.6
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• pp.7-17
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• 2000

The Purpose of this study is to test the effectiveness of Special Transportation Management Zone system (TZ) when it is applied to Dongdaemoon commercial zone located in downtown Seoul. The study consists of two Parts ; the legal components of TZ and the case study on Dongdaemoon district. The case study includes the analysis of current traffic situation on the study zone, the design of implemention alternative for each component of TZ, the framework of impact analysis system, and the analysis results. The study finds, if 2,000 won mandatory parking fee on drivers parking in the buildings only with over 10 parking spaces and over 3.000$m^2$ in floor area, strong illegal parking enforcement, and Pro-hibition of parking passenger cars whose last digit plate number matches with the last digit of date, are implemented in the zone simultaneously, the traffic speed increases to 20.56km/h which is above the target set in the zone. In conclusion, we find that TZ2 can be an effective tool relieving traffic congestion in Seoul, and that it is necessary for introducing TZ in Seoul that relevant laws should be revised and expecting problems should be overcome.

• Journal of Radiation Protection and Research
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• v.32 no.3
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• pp.97-104
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• 2007

The corelation between the indoor volume and the measured radon concentration has been analyzed by comparing the radon concentration and the indoor volume of apartment rooms in Jeonju City. We also measured the annual exposure dose based on the variation in indoor radon concentration over time. To do this, we took 8 larger rooms and 8 smaller rooms of apartment, respectively, as a sample. The average volume of the larger rooms and that of the smaller rooms were $31.59\;m^3$ and $16.82\;m^3$, respectively. The average radon concentration of the larger rooms and that of the smaller rooms turned out to be $71.73\;Bq/m^3$ and $108.51\;Eq/m^3$, respectively. indicating that indoor volume is in inverse proportion to the radon concentration, i.e., the bigger the ratio of the surface area/volume, the higher the indoor radon concentration. From the measurement of the variation in indoor radon concentration over time fur a single day, the average intraday radon concentration variation was found to be about $46.8\;Bq/m^3$. The highest level of concentration ($114.5\;Bq/m^3$) was measured between 8 and 10 AM and the lowest level of concentration ($67.7\;Bq/m^3$) between 2 and 4 PM. The annual exposure dose turned out to be in the range of 0.3 mSv/yr to 2.16 mSv/yr, showing that the dose in some apartments exceeded 1.3 mSv/yr, the numerical value presented by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR).

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.207-212
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• 2001

The environmental characteristics, absorption rate of NO$_2$, physiological response, and quality of lettuces were examined in a semi-closed plant production system consisted of human and plant modules. Leaf lettuces were transplanted to 10-cm diameter pots at 4-to 5-leaf stage, and grown in a gas-fumigated plant module. Air containing NO$_2$was circulated 10 min-ON/ 20 min-OFF between the human and plant modules by a diaphragm. At 0.13, 0.30, and 0.45 $\mu$mol.mol$^{-1}$ NO$_2$, NO$_2$ decrements in the chamber during the 10 min were 0.040, 0.109, and 0.149 $\mu$mol.mol$^{-1}$ , respectively. The NO$_2$absorption rate of the plants was estimated to be 0.078 $\mu$mol.mol$^{-1}$ .m$^{-2}$ .min$^{-1}$ at 0.45 $\mu$mol.mol$^{-1}$ NO$_2$ was less than that of the control plant at 4th and 5th days, whereas the respiration rate was the same. The lettuce grown at 0.45 $\mu$mol.mol$^{-1}$ NO$_2$ had similar leaf length, leaf area, dry and fresh weights, and quality to that grown without NO$_2$.

• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.505-511
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• 1994

Seeds of Rigitaeda pine tree(Pinus rigida${\times}$P. taeda) was primed with polyethylene glycol(PEG-6000) under different PEG concentrations, treatment period, and temperatures to test uniformity of germination. Coated seeds and PEG treated seeds were sown to compare germination, emergence, establishment, and seedling growth. The results obtained are summarized as follows : 1. As the concentration of PEG increased, as total germination percentage of pine tree was increased. Total germination percentage of pine tree seeds primed with PEG at 15 or $20^{\circ}C$ was better than the seeds treated at $10^{\circ}C$ compared to untreated seeds. 2. Germination rate was improved as primed period long and level of PEG concentration high. 3. Maximum germination rate was high with long PEG treatment period, and markedly improved when the seeds were primed at $20^{\circ}C$ 4. Priming with PEG at $20^{\circ}C$ for 12 days reduced time taken for germination. 5. Osmoconditioned seeds accelerated germination under drought condition with injurious effect of coated seeds by some chemicals. 6. There were much differences in establishment and dry matter production between drill and oversowing method, and primed seeds showed better performances than the coated seeds. Coating effects to seeds were better under drought soil condition rather than moderate moisture condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.4
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• pp.359-362
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• 1984

This experiment was carried out to determine the effect of cooking methods of boiling and frying on the removal of mercury from vegetables. Garand chrysanthemums and the leaves of young radishes contained 0.23 and 0.15 ppm of mercury, respectively. When they were boiled, the content of the mercury decreases to 78 percent in garland chrysanthemums and 73 per cent in radish leaves. When they were fried, the content of the mercury decreases to 69 percent in garland chrysanthemums and 60 percent in radish leaves. After the vegetables were exposed to 0.11 ppm of mercury dichloride for 2 hours, the raw garland chrysanthemums and the raw young radish leaves were contaminated with 6.65, 6.10 ppm of mercury, respectively. When the vegetables were boiled after this contamination, the mercury was dissolved and. melted out about 10.0%, however, when the vegetables were fried the mercury was dissolved and melted out about $12{\sim}24%$. When the vegetables were exposed to 1.0 ppm of mercury dichloride, the raw garland chrysanthemums was contaminated with 10.79 ppm of mercury and the radish leaves 10.83 ppm of mercury. The mercury was dissolved and melted out about 10-20% and 10-30% when the vegetables were boiled and fried, respectively. From these results, it can be suggested that frying is more effective cooking method than boiling for the elimination of mercury from its contaminated foods.