• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.614-625
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• 2004

The main purpose of this study is to get flowrate coefficient 'q' and to study characteristics of flowrate of screw pump. This study is based on Muskin's formula and depends on the computer simulation. The results of study are as follows. 1. Flowrate coefficient will reduce according to increase of inclination. The larger the pitch ratio is and the smaller the diameter ratio is, the more coefficient reduces. 2. As a rule, the coefficient increases according to reduction of the diameter ratio, but the coefficient tends to reduce when the ratio is less than 0.45. So, in actual application, it is recommended that the ratio should be above 0.45. 3. If the pitch ratio increases, the coefficient increases in case of small inclination and decreases in case of large inclination. 4. The coefficient increases according to number of windings. Especially, singles winding is not used in actual application because it has too small coefficient. 5. The coefficient decreases when the influent water level falls. Flowrate is almost zero when the water level is below $40\%$ of Filling Points.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.83-88
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• 1999

The purpose of this study is to offer the basic information of waterproofing admixture of powder for field application. Through before study and fly ash in mortar, Various properties as fly ash ratio in concrete were checked. According to the experimental result, it was shown that proper Waterproofing admixture of powder increased by cement weight in concrete was generally positive effect to flowing, compressive strength, suction ratio of water, length change ratio. So if Waterproofing admixture of powder is well done quality considered as good on application of concrete.

• Journal of Biosystems Engineering
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• v.35 no.4
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• pp.215-223
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• 2010

In order to develop an precision aerial pesticide application system to be attached to an unmanned helicopter which can be applied to small lots of land, this study analyzed the flowing and spraying characteristics of the spray droplets by the main rotor downwash by setting the application conditions at the flight altitude of 3 m, the diameter of main rotor of 3.1 m, the boom length of around 2.8 m, and the spraying rate of 8 L/ha. The results of this study are summarized below. Through analysis of the covering area ratio of the spray droplets by main rotor downwash by nozzle type, boom with tilt angle and height, it was found that the covering area ratio of the twin flat-fan nozzle of around 25% was more uniform than other types of nozzle, also boom with $10^{\circ}$ tilt angle and spraying height of 3 m was shown to be the appropriate conditions for aerial application of pesticides. It was found that the nozzle position to minimize the scattering loss of spray droplets due to vortex phenomenon at both ends of the main rotor was around 10 cm from the end of the main rotor. An application test for the aerial pesticide application system attached to the HUA-ACEI unmanned helicopter developed by the Rural Development Administration showed that the range of covering area ratio of the spray droplets was 10-25%, and the spraying width was approximately 7 m when over 10% of covering area ratio was considered for valid spraying.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.65-70
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• 2004

The purpose of this study is to offer the basic information of waterproofing admixture of powder for field application. Through before study and fly ash in mortar, Various properties as fly ash ratio in concrete were checked. According to the experimental result, it was shown that proper Waterproofing admixture of powder increased by cement weight in concrete was generally positive effort to flowing, compressive strength, suction ratio of water, length of ratio. So if Waterproofing admixture of powder il well done quality considered as good in application of concrete.

• Journal of Korean Association for Spatial Structures
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• v.14 no.4
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• pp.39-46
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• 2014

In Seoul, total 27 places of foot-bridges were chosen to evaluate the damping ratio through vibration measurement by mobile-phone application. Model vibration test was performed to compare the natural frequency and damping ratio between the conventional accelerometer and mobile-phone application. Measured average damping was compared with the one of Bachmann. The relation between the damping ratio and span was also investigated. Measured average damping ratio was greater than that of Bachmann. It was shown that there is no distinct trend between damping and span.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.373-379
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• 2010

The artificial upwelling of deep seawater increases primary production. This study conducted a lab-scale experiment to investigate the growth of phytoplankton with the mixing ratio of deep and surface seawater. The chlorophyll content in the sample of pure deep seawater was highest, regardless of the phytoplankton groups. Nutrients contained in the deep seawater positively influenced the growth of phytoplankton. The optimum mixture to apply in an artificial upwelling system was a 1:1 ratio of deep and surface seawater. An experiment considering other environmental conditions, such as luminance and specific gravity, should be performed.

• Journal of dental hygiene science
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• v.6 no.2
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• pp.93-99
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• 2006

This study was carried out to investigate practical application status of oral hygiene devices through making a survey of labor of the D industrial company-about carefully curing oral disease in home, the status of practical application of tooth brush, the status of practical application of fluoridated toothpaste, status of practical application of auxiliary oral hygiene devices, a motive use or unuse of auxiliary oral hygiene devices. 1. In home, carefully curing oral disease is dental caries(62.4%). 2. Status of practical application toothbrush showed the highest user ratio of mideum size(79.6%). 3. Showed the highest user ratio of horizontal plane toothbrush(73.5%). 4. Answerd don't take a prudent attitued in choice of fluoridated toothpaste(73.5%). 5. In the status of reconition of oral hygiene devices, showed the highest user ratio of eletric toothbrush(77.0%). 6. In the status of reconition of auxiliary oral hygiene devices, showed the highest user ratio of wooden wedge stimulator(89.4%)and gargle liquid(84.5%). In using of oral hygiene devices, showed the highest user ratio of electric toothbrush(13.3%), toohbrush for periodontal patients(2.7%). In using of auxiliary, wooden wedge stimulator (58.4%)and gargle liquid(41.2%). In effect using of oral hygiene devices showed the highest user ratio of denture brush(50.0%)and eletric toothbrush(43.3%), in effect using of auxiliary oral hygiene devices showed the highest user ratio of water pick(80.0%) and dental floss(75.8%). 6. A motive of the use auxiliary oral hygiene device is choice by oneself through TV, advertisement, public information(57.6%), and the reason-they don't use of auxiliary oral hygiene devicebecause of they don't know proper to them the kind of auxiliary oral hygiene device.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.147-155
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• 1977

In this experiment, we expected yield increase depending on the control of ineffective tiller, heightening of effective tillering ratio and continuous supply of nitrogen until later growth stage of rice plant by deep layer split application. Treats were applied at Tongil and Jinheung variety, clayey loam and sandy loam soil, and drained and non-drained condition. Nitrogenous fertilizer application wab adopted as liquefied(50%) and lumped (50% and 80%) fertilizer at 12cm depth of soil before 35 days of rice heading time against the standard soil surface application. The results are summarized as follaw. 1. a. Jinheung showed great variant width of tiller numbers per rice plant growth stage, and low effective tillering ratio at soil surface dressing. But in the case of deep layer split application, the number of tiller increased normally, and effective tillering ratio was high. b. At Tonsil, the width of increase and decrease range of effective tiller number between soil surface dressing and deep layer split application was not so high as Jinheung. Deep layer split application of 80% lumped fertilizer showed maximum effective tillering ratio ($83%{\sim}93%$). C. In the case of Jinheung, it was supposed that deep layer split application of 80% lumped fertilizer was excessive nitrogen quantity. d. Effective tillering ratio was higher than Tonsil at Jinheung. 2. The number of grains per hill was increased by the deep layer split application, but the ripening ratio was decreased inversely with the increase of total grain number. 3. Length of top leaves was elongated at Jinheung by deep layer split application. It showed significant correlation between top leaves length and grain yield. 4. Deep layer split application inclosed N content of harvested straw. Yield and N content of straw showed possitive correlation. 5. The ratio of unhulled grain yield per straw weight was increased by deep layer splication. This ratio was higher at Jinheung than Tonsil. 6. Grain yield was appeared in order of 80% lumped fertilizer>50% lumped fertilizer>50% liquefied fertilizer>surface dressing by the deep layer split application. The yield increasing factors were the increasing of effective tillering ratio, number of panicles per hill and number of ripening grains per hill. 7. Grain yield was increased at Tongil in sandy loam soil and at Jinheung in clayey loam soil by deep layer split application. 8. The grain yield was increased at drained conditions of clayey loam soil and non-drained conditions of sandy loam soil. But in the case of 80% lumped fertilizer of deep layer split application at the sandy loam soil, the yield was not increased at non-drained conditions. 9. The effect of yield increase by deep layer split application comparing with the surface dressing was higher at Tonsil than ginheung, in spite of low ripening ratio of Tonsil caused by low temperature at heading and harvesting time.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.19-26
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• 2009

The Ministry of Land, Transport and Maritime Affairs(MLTM) project for the DB construction of national geotechnical information was automatically computerized the geotechnical investigation results on the construction site in 2007. So 'the rule for computerizing of geotechnical investigation results and its application' were promoted the establishment and applicable project. It was promoted in earnest that all organization and affiliation of MLTM, local governments included the project because of stabilization of the law from 2008. We have analyzed a application-ratio of geotechnical information about users of geotechnical information system and distribution data and established a plan of applying enhancement for the DB construction and DB utilization in 2008. In this paper, we propose the result for application-ratio analysis and application plan through the application-case study of national geotechnical information DB. In the application-ratio analysis, the analysis in the field shows the most high as 39% in construction planning and preliminary investigation, the analysis in the effect of capabilities shows the most high as 25% in the increased efficiency of business. Also the analysis in the field of application shows the most high as 95% a application-ratio of geotechnical information in architecture and civil.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2287-2296
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• 2002

Most cracks in the structure occur under mixed mode loading and those fatigue crack propagation behavior heavily depends on the stress ratio. So, it is necessary to study the fatigue behavior under mixed mode loading as the stress ratio changes. In this paper, the fatigue crack propagation behavior was respectively investigated at stress ratio 0.1, 0.3, 0.5, 0.7 and we changed the loading application angle into 0$^{\circ}$, 30$^{\circ}$, 60$^{\circ}$ to apply various loading mode. The mode I and II stress intensity factor of CTS specimen used in this study was calculated by the displacement extrapolation method using FEM (ABAQUS). Using both the experiment and FEM analysis, we have concluded the relationship between crack propagation rate and stress intensity factor range at each loading mode due to the variation of stress ratio. Also, when the crack propagated under given stress ratio and loading mode condition, we have concluded the dominant factors of the crack propagation rate at each case.