• The Journal of the Korean dental association
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• v.53 no.2
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• pp.132-142
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• 2015

Purpose : The objective of this research was to investigate an optimization of drill design factors for implant stability and efficacy through comparative evaluation by the cutting time, heat generation and initial stability. Materials and Methods : Three design factors were considered for the purpose of drill design optimization; the number of flute(2 flute, 3 flute), helix angle($15^{\circ}$, $25^{\circ}$) and drill tip shape(straight, 2-phase). Design factors were selected through comparative evaluation by temperature change, cutting time and ISQ value. Results : Heat generation and cutting time are influenced by all design factors(p<0.05). Drill tip shape was the only factors which influenced to the largest initial stability(p<0.05). Conclusion : Drills with 2 flutes, 2-phase formed drill tip, and 25 degrees of helix angle exhibit a better performance than other design.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.81-89
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• 1995

One of the most difficult problem to estimate the flood inflow is how to understand the effective rainfall. The effective rainfall is absolutely influenced by the condition of soil moisture in the watershed just before the storm event. DAWAST model developed to simulate the daily streamflow considering the meteologic and geographic characteristics in the Korean watersheds was applied to understand the soil moisture and estimate the effective rainfall rather accurately through the daily water balance in the watershed. From this soil moisture and effective rainfall, concentration time, dimensionless hydrograph, and addition of baseflow, the rainfall-runoff model for flood flow was developed by converting the concept of long-term runoff into short-term runoff. And, real-time flood forecasting model was also developed to forecast the flood-inflow hydrograph to the river and reservoir, and called RETFLO model. According to the model verification, RETFLO model can be practically applied to the medium and small river and reservoir to forecast the flood hydrograph with peak discharge, peak time, and volume. Consequently, flood forecasting and warning system in the river and the reservoir can be greatly improved by using personal computer.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.6
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• pp.72-82
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• 2000

Many lot of books introduce the methods to calculate the time of concentration, and these are described as various forms of formulas. There are few formulas appropriate for our basin characteristics Therefone, there are problems to make excessive or less estimation when these formulas are used. To solve these problems, comparison of formulas and sensitivity analysis for them were made with converting parameters. Finally, Time of concentration was estimated to derive Application limits for 3 watersheds by standardized formulas. In the case of input parameters analysis, SCS formula has the highest value by the length, Kerby by the height and SCS by the slope, respectively, while Kraven formula has the lowest value among them. Concerning the relative sensitivity by Taylor series, the time of concentration showed the constant effect while increasing of the length and slope, and the length was more sensitive than the slope in parameters. Finally the standardization formula developed in this study was applied to derive application limits for 3 watersheds(total 17 subbasins). In this case, Rziha(8 subbasins) and SCS(9 subbasins) formulas were the most similar to observed data of total 17 subbasins respectively. Application limits were about 300~500$\textrm{km}^2$ area, 30~60km length and under 0.01 slope for Rziha formula and about 100~200$\textrm{km}^2$ area, 10~30km length, and over 0.01 slope for SCS formula, respectively.

• Journal of the korean veterinary medical association
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• v.6 no.4
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• pp.24-28
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• 1962

Virus Pneumonia of Pigs was observed in Korea for the first time. The lung tissues observed were clinical cases of baby pigs and those of cases secured from Abattoir. They were examined Pathologically, both gross and microscopic. The results odserved were

• Magazine of RCR
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• v.12 no.1
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• pp.39-43
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• 2017

• Journal of the Korean Professional Engineers Association
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• v.33 no.5
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• pp.45-48
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• 2000

DyeMax-L system(a real-time dyeing measuring system) which can do on line monitoring of dyeing process and measurement of the exhaustion of individual dye in mixtured dyes were developed By using the instrument, the compatability of mixture dyes and changes of exhaustion behavior of each dye with the variation of dyeing auxiliaries and dyeing conditions to get factors for control of dyeing

• Broadcasting and Media Magazine
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• v.17 no.4
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• pp.69-80
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• 2012

• The Korean Nurse
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• v.20 no.3 s.111
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• pp.58-65
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• 1981

It is desirable to utilize the community health resources to manage community health services effectively with limited personnel, time and facilities. This study was conducted to determine the utilization of community health resources. During the period o

• The Korean Nurse
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• v.5 no.1 s.21
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• pp.10-31
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• 1966

The advance of ''nurse'', in the ture sense of the meaning, dates back to the year 1884, when a coup detat was attempted by the progressive minority against the dominant Conservatives; and when for the first time the Western wisdom of medical science bega

• 정보화사회
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• s.138
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• pp.44-47
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• 2000

사이버교육의 가장 큰 매력은 시간과 공간의 제약을 받지 않는다는 것과 학습자(수요자) 중심의 학습이 가능하다는 것이다. 사이버교육은 인터넷이 접속 가능한 환경에서는 언제 어디서나 자신의 필요에 따라 (on-demand), 적시에(just-in-time)교육을 받을 수 있기 때문에 접근성이 높다. 특정 시간에 특정 강의실을 찾아야 하는 전통 교육 방식과 비교했을 때, 시간과 비용의 불필요한 낭비를 제거하고, 교육 기회를 넓혀 준다.