• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1326-1333
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• 2007

For preparing the basic ingredients of Gomtang-like products from the extracts of salmon frame, the extraction conditions of salmon frame were examined, and the characteristics of the extracts were compared with commercial Gomtang. Based on the crude protein, Ex-N and sensory attributes, the extractions were optimized by extracting pretreated-salmon frame in 12 times (v/w) of water for 12 hrs, before filtering with cheese cloth to yield 3 times the volume of the raw material. The concentrations of heavy metals in extracts from salmon frame were below the safety limits suggested by KFDA. The mai or amino acids were glutamic acid and aspartic acid as the free amino acids, and glycine, proline, and glutamic acid as the total amino acids. The calcium and phosphorus contents were 18.0 mg/100 mL and 33.1 mg/100 mL, respectively, and they accounted for 20% and 18% of the recommended daily allowance for mineral intake. The angiotensin I converting enzyme (ACE) inhibitory activity was improved by incubation with Flavourzyme for 4 hrs and its $IC_{50}$ was 2 mg/mL. The results above suggested that the enzymatic hydrolysates from extracts of salmon frame could be used as a basic ingredient for preparing Gomtang-like products.

• Journal of Acupuncture Research
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• v.22 no.3
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• pp.13-22
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• 2005

By extracting the sample of Ulmus davidiana Planch(Ulmaceae), which was known to have the protection of damaged organ and the anti-inflammation action, it was experimented whether it is available for the application of treatment of osteoporosis. In the previous experiment, the extracts from Ulmus davidiana Planch(Ulmaceae) were confirmed to inhibit Cathepsin K through treating the cell of long bone, which contains osteoclast. Through this, it is suggested that Ulmus davidiana Planch(Ulmaceae) can play a role of prodrug as an inhibitor of absorbing bone ash in the treatment of osteoporosis. In the present experiment, a research in vitro Ulmus davidiana Planch(Ulmaceae) on the growth and sensibilization of osteoblast in a state that induced osteosis by using the cell tissue of MC3T3-El pre-osteoblastic was conducted. As a result, it could be confirmed that Ulmus davidiana Planch(Ulmaceae) has the strengthening function by enhancing the dosage and the activity of ALP depending on the time. The dosage was observed at the minimum of $50{\mu}g/m{\ell}$ and the maximum of $150{\mu}g/m{\ell}$. The enhancement in bone morphogenetic protein-2 at $100{\mu}g/m{\ell}$ UD could be observed, and it also increased the concentration of ALP mRNA within the cell of MC3T3-El. At $60{\mu}g/m{\ell}$ UD which indicated a little increase in Type I collagen mRNA for a long time of culture. However, it was shown to sharply inhibit the expression of gene in the culture between 15-20 days. These results suggest that Ulmus davidiana Planch(Ulmaceae) has an influence upon bone metabolism through thje sensibilization of osteoblast. Therefore, it could be known that utilized Ulmus davidiana Planch(Ulmaceae) can be positively applied for the general disease of bone metabolism through future studies.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.52-68
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• 1991

A new propeller series is developed using the newly developed blade section(KH18 section) which behaves better cavitation characteristics and higher lift-drag ratio at wide range of angle-of-attack. The pitch and camber distributions are disigned in order to have the same radial and chordwise loading distribution with the selected circumferentially averaged wake input. Since the geometries of the series propeller, such as chord length, thickness, skew and rate distribations, are selected by regression of the recent full scale propeller geometric data, the performance prediction of a propeller at preliminary design stage can be mure realistic. Number of blades of the series propellers is 4 and the expanded blade area ratios are 0.3, 0.45, 0.6 and 0.75. Mean pitch ratios are selected as 0.5, 0.65, 0.8, 0.75 and 1.1 for each expanded area ratio. The new propeller series is composed of 20 propellers and is named as KD(KRISO-DAEWOO) propeller series. Propeller open water tests are performed at the experimental towing tank, and the cavitation observation tests and fluctuating pressure measurements are carried out at the cavitation tunnel of KRISO. $B_{P}-\delta$ curves, which can be used to select the optimum propeller diameter at the preliminary design stage, are derived from a regression analysis of the propeller often water test results. The KD-cavitation chart is derived from the cavitation observation test results by choosing the local maximum lift coefficient and the local cavitation number as parameters. The caviy extent of a propeller can be predicted more accurately by using the KD-cavitation chart at a preliminary design stage, since it is derived from the results of the cavitation observation tests in the selected ship's wake, whereas the existing cavitation charts, such as the Burrill's cavitation chart, are derived from the test results in uniform flow.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.111-131
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• 1975

The study has been carried out to investigate the occurrence, damage, characteristics of the pathogen, environmental conditions affecting the disease outbreak, varietal resistance, forecasting, and chemical control of bacterial leaf blight of rice in Korea since 1964. Bacterial leaf blight of rice became a major disease in Korea since 1960. A correlation was found between the annual increase of epidemics and increase of cultivation area of susceptible varieties, Jinheung, Keumnampung etc. Areal damage within the country showed that the more was at southern province, Jeonnam, Gyeongnam and western coast, and at flooded rice paddy. Yield reduction directly related with the amount of infection on upper leaves at heading stage. Fifty per cent of reduction resulted when the lesion area was more than 60 per cent. Less than 20 per cent of lesion area, however, was not affected so much on yield loss One hundred and six isolates collected from all over the country were classified as 8 strains by using 4 different bacteriophages in 1973. It was, however, only two in 1965. There were some specificities on varietal distributions among the strains such as that the Jinheung attacked mainly by strain A, B, C and I, those attack Kimmaze were A, B, H and I. Most strains were found from Tongil except D and E, whereas Akibare was only variety that attacked by strain E. Low temperature, high humidity, heavy rainfall and insutficient daylight favored the disease epidemics. Especially, typhoon and flooding at heading stage were critical factors. The earlier transplanting the more disease was resulted, and more nitrogen fertilizer application accerelated the diseased development in general. The resistance to the disease varied by growing stage of the sane plants. All of recommended varieties in Korea were susceptible to the disease except Norm No. 6 and Sirogane which moderately resistant. The pathogen, Xanthomonas oryzae, was detectable from extract of healthy seedlings that were grown in the field with an heavy infection previous year. The more bacteriophage in irigation water resulted the more disease outbreak, and the existence of more than 50 bacteriophages in 1ml. of irrigation water were necessary to initiate the disease out break. The curves representing occurrence of bacteriophages and disease outbreak were similar with 15 days interval. The survey of bacteriophage occurrence can be utilized in forecasting of the disease two weeks ahead of disease outbreak. Three applications of chemicals, Phenazin and Sangkel, in weekly intervals at the early satage of out-break depressed the symptom development, and increased yield by 20per cent. Proper period for the chemical application was just before the number of bacteriophage reaches 50 in 1ml. of irrigation water.

• Korea journal of population studies
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• v.28 no.2
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• pp.1-32
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• 2005

The optimum population of a society or country can be defined as 'the population growth path that maximizes the welfare level of the society over the whole generations of both the present and the future, under the paths allowed by its endowments of production factors such as technology, capital and labor'. Thus, the optimum size or growth rate of population depends on: (i) the social welfare function, (ii) the production function, and (iii)demographic economic interrelationship which defines how the national income is disposed into consumption(birth and education of children included) and savings on the one hand and how the demographic and economic change induced thereby, in turn, affect production capacities on the other. The optimum population growth path can, then, be derived in the process of dynamic optimization of (i) under the constraints of (ii) and (iii), which will give us the optimum population growth rate defined as a function of parameters thereof. This paper estimates the optimum population growth rate of Korea by: specifying (i), (ii), and (iii) based on the recent development of economic theories, solving the dynamic optimization problem and inserting empirical estimates in Korea as the parametric values. The result shows that the optimum path of population growth in Korea is around TFR=1.81, which is affected most sensitively, in terms of the size of the partial elasticity around the optimum path, by the cost of children, share of capital income, consumption rate, time preference, population elasticity of utility function, etc. According to a survey implemented as a follow up study, there are quite a significant variations in the perceived cost of children, time preference rate, population elasticity of utility across different socio-economic classes in Korea, which implied that, compared to their counterparts, older generation and more highly educated classes prefer higher growth path for the population of Korea.

• Journal of Korea Water Resources Association
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• v.41 no.3
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• pp.277-291
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• 2008

In order to carry out river basin management, it is necessary to evaluate the state of the river basin and make site-specific measures on the basis of management goals and objectives. A river basin is divided into several watersheds, which are composed of several components: water resources, social and economic systems, law and institution, user, land, ecosystems, etc. They are connected among them and form network holistically. In this study, a methodology for evaluating watershed management was developed by consideration of the various features of a watershed system. This methodology employed factor analysis to develop sub-indexes for evaluating water use management, environment and ecosystem management, and flood management in a watershed. To do this, first, the related data were gathered and classified into six groups that are the components of watershed systems. Second, in all sub-indexes, preliminary tests such as KMO (Kaiser-Meyer-Olkin) measure of sampling adequacy and Bartlett's test of sphericity were conducted to check the data's acceptability to factor analysis, respectively. Third, variables related to each sub-index were grouped into three factors by consideration of statistic characteristics, respectively. These factors became indicators and were named, taking into account the relationship and the characteristics of included variables. In order to check the study results, the computed factor loadings of each variable were reviewed, and correlation analysis among factor scores was fulfilled. It was revealed that each factor score of factors in a sub-index was not correlated, and grouping variables by factor analysis was appropriate. And, it was thought that this indicator system would be applied effectively to evaluating the states of watershed management.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.254-264
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• 2004

Purpose: This study was carried out to confirm clinical values and limitations of postoperative radiotherapy for hypopharyngeal carcinoma, to evaluate various prognostic factors which may affect to the treatment results and to use these results as fundamental data for making a new treatment strategy. Methods and Materials:. A retrospective analysis was peformed on 64 previously untreated patients with squamous cell carcinoma of the hypopharynx, seen between 1988 and 1999 at Pusan National University Hospital. Most of patients were treated by laryngopharyngectomy and neck dissection followed by conventional fractionated postoperative radiotherapy on surgical bed and cervical nodal areas. Results: The five-year overall survival rate and cause-specific survival rate were 42.2 percent and 51.6 percent, respectively. Univariate analysis of various clinical and pathologic factors confirmed the overall stage, TN-stage, secondary primary cancers, surgical positive margin, nodal extracapsular extension, total radiation doses as significant prognostic factors of hypopharyngeal carcinomas. But in multivariate analysis, TN-stage, surgical positive margin and extracapsular extesion were only statistically significant. Conclusion: In resectable cases of hypopharyngeal carcinoma, combined surgery and postoperative radio-therapy obtained good treatement results, even though sacrificing the function of larynx and pharynx. But in advanced and unresectable cases, with respect to survivals and qualify of life issues, we were able to confirm some limitations of combined therapy. So we recommend that comparative studies of recent various chemo-radiotherapy methods and advanced radiotherapy techniques with these data should be needed.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.525-528
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• 2001

This study was conducted to estimate the contents of heavy metals in some health foods available on Korean markets. The samples were digested with microwave system, then analyzed using GF-AAS for the contents of lead (Pb), cadmium (Cd) and arsenic (As). The contents of mercury (Hg) were determined using a mercury analyzer. The average values of Hg, Pb, Cd and As in calcium (Ca) health foods were 0.007, 1.08, 0.02 and 0.48 mg/kg respectively. Those values in chitosan health foods were 0.001, 0.36, 0.01 and 0.03 mg/kg respectively. Those values in propolis health foods were 0.013, 4.96, 0.01 and 0.13 mg/kg, respectively. The health foods that contained cow bone powders had the highest lead contents. Based on the variation in lead contents of those products, it could be possible that they might be contaminated through raw materials and/or manufacuring process. Some propolis products were also very high in lead contents. There could be risks for some population, especially the aged who overtake those health foods, to have heavy intake of lead. Therefore, we established the lead standards of 3.0, 2.0 and 5.0mg/kg less than for Ca, chitosan and propolis health foods respectively, based on the Codex method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.926-934
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• 2006

The base for preparing oyster hydrolysate-added yogurt was consisted of whole milk (1,000 mL), skim milk (44.05 to 42.05 g), enzymatic oyster hydrolysates powder (OHP, 0 to 2.0 g) and pectin. The yogurt base was fermented with 7 kinds of starter cultures (3% based on yogurt volume), such as Lactobacillus acidophilus, lactobacillus bulgaricus, lactobacillus casei, Lactobacillus fermentum, Lactobacillus pentosus, Streptcoccus thermophilus and the mixed starters (L. bulgaricus and S. thermophilus) at optimal temperature. Processing condition and quality characteristics of the yogurt were evaluated by analyzing pH, titratable acidity, viscosity, viable cell count, functional properties and sensory evaluation. The results suggested that the optimal conditions for preparing the good quality yogurt revealed the mixed starters (L. bulgaricus and S. thermophilus) for starter culture, 1.0 g of 3 kDa hydrolysate for amount, and 5.5 hrs for fermentation time. The good quality yogurt showed 4.31 for pH, 1.07% for titratable acidity, 469 cps for viscosity and $4.9{\times}10^8\;CFU/mL$ for viable cell count. The hydrolysate-added yogurt was 2 times higher in ACE inhibitory and antioxidant activities than commercial yogurt, and kept good quality during storage of 15 days at $5^{\circ}C$.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.119-127
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• 2012

For the promotion of the evaporative cooling efficiency of hot air in greenhouse in summer, a fog sprayer consisted of a high volume spraying two-fluid nozzle with turbo fan and a blowing fan was set up at 2.2 m height from bottom of small glass greenhouse and tested to estimate the possibility of the greenhouse cooling. The mean droplet size and the volume sprayed by one of fog sprayer were $29{\mu}m$ and $160m{\ell}/min$. All the droplets sprayed and blown by the fog sprayer were evaporated within 2 m radius. The result from the cooling test that two sprayers set up in glass greenhouse of plane area $228m^2$ was represented lower cooling effect that the temperature and relative humidity of inside air of greenhouse were $28.8^{\circ}C$ and 87.5% when those of outside air of greenhouse were $30.2^{\circ}C$ and 81.2%. Through investigation of literatures and results of the cooling test, it was estimated that the water spraying rate of evaporative cooling of single span greenhouse with 50% light curtain and with air change rate of 1 volume/min was $10m{\ell}/min/m^2$ so that the inside air temperature may cool down $2{\sim}3^{\circ}C$ on the basis of $35^{\circ}C$ atmospheric temperature in summer of south korean area.