• 제목/요약/키워드: formula comparison

검색결과 528건 처리시간 0.037초

얕은기초의 지지력 산정방법에 관한 비교 연구 (Comparison of Bearing Capacity Calculation Methods for Shallow Foundations)

  • 천병식;이정훈;김수봉
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.455-462
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    • 2003
  • The current practice of estimating bearing capacity usually employs the conventional bearing capacity formula originally developed for strip footings under vertical central loading, In order account for the effect of footing shape and eccentricity and inclination of loads, correction factors are introduced in the formula, which are derived based on a number of small-scale model test observations. In this paper, comparison of several formulations of bearing capacity factors, as well as values of these factors, are presented. And the conventional bearing capacity equations are compared with some of other failure loci proposed for cohesive soil. Also, the bearing capacity of shallow foundation estimated by the conventional bearing capacity equations are compared with the experimental load test results.

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덱크플레이트를 사용한 경량콘크리트 슬래브와 철골보의 합성보에서 쉬어코넥터의 내력에 관한 연구 (A Study on Strength of shear Connectors in Composite Beams of Steel and Lightweight Concrete Slabs with Deck Plate)

  • 김종식;박성무
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.293-298
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    • 1995
  • The strength of shear connectors embedded in lightweight concrete slab with deck plate is influenced by various factors of deck plate, shear conncetor and concrete. Generally, it is reported that the strength of shear connector in lightweight concrete decreases in comparison with that in normal concrete. So this paper is to use compressive strength of lilghtweight concrete, width-height ratio of deck plate, and cross sectional area of shear conncetor as variables, to evaluate the strength of shear conncetors in composite beam of steel and lilghtweight concrete slabs with deck plate, and then to suggest the reasonable strength equation by comparing the push-out test results with establixhed strength formula. As the result of 24 specimens test, in case of lightweight concrete slab with deck plate, it has showed that in the same strength, the strength of shear connector decreased about 10~20% in comparison with that in normal concrete. In spite of lightweight concrete, the test results were closely approached the established strength formula of shear connector using Fisher's reduction coefficient.

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한국 유가공업의 발전과 전망 - 조제분유 (Development of Korean Dairy Industry - Infant Formula)

  • 진현석
    • Journal of Dairy Science and Biotechnology
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    • 제23권2호
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    • pp.155-160
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    • 2005
  • 전세계 많은 나라들은 조제분유를 특수 영양식품으로 분류하여 관리에 각별히 신경을 쓰고 있으며, CODEX에서는 첨가되는 거의 모든 성분을 모유에 들어 있는 것이어야 하며, 또한 과학적으로 안전성이 입증된 것만을 넣을 수 있도록 규정하고 있다. 이 때문에 분유 메이커들은 제품 개발을 위해 많은 모유 및 우유 성분에 관한 연구를 바탕으로 하여 모유의 조성에 맞추는 노력을 하고 있다. 국내산 분유는 외국 제품에 비해 면역기능 향상, 항-알레르기 능력 향상, 뇌와 소화기관의 발달 등을 돕는 성분이 강화되어 있다. 현재 생명과학기술의 진보와 각종 신기술의 도입으로 모유 및 우유속의 극미량 성분까지 분리정제가 가능함에 따라 다양한 기능성을 갖는 성분들이 상품화되고 있으며, 이를 이용해 조제분유를 개발하고 있다. 두뇌 발달 성분인 DHA, 아라키돈산 등과 면역기능 강화 성분인 뉴클레오타이드, 락토페린 등의 첨가 및 정장기능을 보이는 올리고당 등의 성분강화에서 이제는 뼈 성장 발달인자, 아토피 및 알레르기의 감소를 위해 가수분해물의 이용 등의 기능을 보강한 다양한 제품이 개발되어지고 있는 중이다.

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일부 모유 영양아와 인공 영양아의 혈중 타우린 함량 비교 (Comparison of Plasma Taurine Levels in Some of Breast-fed Infants and Formula-fed Infants)

  • 조금호;김을상
    • 동아시아식생활학회지
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    • 제15권4호
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    • pp.397-404
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    • 2005
  • The propose of this study was to investigate taurine intake in formula-fed and breast-fed infants and to estimate the level of taurine of blood and urine in order to determine the requirement of taurine intake in infants. These results will be useful to suggest the guideline of requirement of taurine intake and may contribute toward the proper use of breast milk substitutes. Experimental groups were breast-fed infants (n=10) and formula-fed infants (n=10) of 20 normal delivery infants in general hospital. This study was longitudinal study from birth up to 16weeks (0 week, 4 weeks, 8 weeks, 12 weeks, 16 weeks). The items of test were anthropometry(weight, height, head circumference, chest circumference), intake of taurine, taurine level of blood and urine in breast-fed and formula-fed infants. There were no significant differences between breast-fed and formula-fed infants in weight, height, head and chest circumference. There is a need for future studies of exclusive infants with larger samples to determine which growth pattern should be considered as the norm. Taurine concentration of plasma and urine did not differ between breast-fed and formula-fed infants. Taurine intake recommendations for infants is about 30mg/day from this study. This data will be useful for production of human-like formula milk and suggestion of an index of selection of a consumer in taurine.

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유공케이슨 방파제에 작용하는 파력 공식의 비교 (Comparison of the Formulas for the Wave Forces Acting on the Perforated Caisson Breakwater)

  • 지창환;오상호;오영민;이달수
    • 한국해안·해양공학회논문집
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    • 제27권4호
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    • pp.217-227
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    • 2015
  • 본 연구에서는 유공케이슨에 작용하는 파력을 산정하기 위해 제안된 세 가지 파력공식(Takahashi and Shimosako, 1994; Tabet-Aoul and Lambert, 2003; Li, 2007)의 적용성을 검토하기 위하여 2차원 수리실험을 수행하였다. 실험에 의한 계측값과 각 공식에 의한 계산값의 정량적 비교를 위하여 수정 일치지수 및 결정계수를 이용하였고, 이를 통해 계측값과 계산값이 어느 정도 서로 일치하는지 그 정도를 평가하였다. 세 가지 공식 중 DUT 공식(Li, 2007)이 실험값과 계산값 편차가 가장 적었으며, Takahashi 공식(Takahashi and Shimosako, 1994)은 가장 큰 편차를 나타내었다. 한편, 계측 및 계산값의 상대적인 크기를 비교한 결과 Takahashi공식과 Tabet-Aoul & Lambert 공식(Tabet-Aoul and Lambert, 2003)은 실험값에 비하여 파력을 과대산정하고, DUT 공식은 파력을 다소 과소산정하는 경향이 나타났다.

지표화 산불의 화염전파 수치해석 (A Numerical Study of Flame Spread of A Surface Forest Fire)

  • 김동현;이명보;김광일
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.80-83
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    • 2008
  • The characteristics of the spread of a forest fire are generally related to the attributes of combustibles, geographical features, and meteorological conditions, such as wind conditions. The most common methodology used to create a prediction model for the spread of forest fires, based on the numerical analysis of the development stages of a forest fire, is an analysis of heat energy transmission by the stage of heat transmission. When a forest fire breaks out, the analysis of the transmission velocity of heat energy is quantifiable by the spread velocity of flame movement through a physical and chemical analysis at every stage of the fire development from flame production and heat transmission to its termination. In this study, the formula used for the 1-dimensional surface forest fire behavior prediction model, derived from a numerical analysis of the surface flame spread rate of solid combustibles, is introduced. The formula for the 1-dimensional surface forest fire behavior prediction model is the estimated equation of the flame spread velocity, depending on the condition of wind velocity on the ground. Experimental and theoretical equations on flame duration, flame height, flame temperature, ignition temperature of surface fuels, etc., has been applied to the device of this formula. As a result of a comparison between the ROS(rate of spread) from this formula and ROSs from various equations of other models or experimental values, a trend suggesting an increasing curved line of the exponent function under 3m/s or less wind velocity condition was identified. As a result of a comparison between experimental values and numerically analyzed values for fallen pine tree leaves, the flame spread velocity reveals has a error of less than 20%.

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강도비를 적용한 Rice-저항곡선과 변형경화를 고려한 $J_{\delta}$-저항곡선과의 비교 (On Reliability and Comparison of $J_{Rice}$-Resistance considering Optimal Strength Ratio and $J_{\delta}$-Resistance Curves converted from CTOD using Appropriate Strength chosen according to Strain Hardening Level)

  • 장석기
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권1호
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    • pp.59-67
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    • 2002
  • The comparison of $J_{Rice}$-resistance considering a few strength ratio in Rice J-integral formula and $J_{\delta}$-resistance curves converted from experimental CTOD using appropriate strength chosen according to strain hardening level, n=10.6 (A533B steel) and n=8.1 (BS4360 steel) is carried out. The optimal dimensionless strength ratio like the factor of revision, (see full text)reflecting strain hardening level in Rice\`s experimental formula is found out and the reliability of appropriate reference strength chosen according to strain hardening level in different materials is investigated through doing that CTOD is transformed from $J_{\delta}$-integral using relationship between J-integral and CTOD. The results are as follows; 1) The optimal factor of revision is when m equals to 3 in (see full text) for Rice's and the above optimal factor of revision multiplies by coefficient, η in Rice's experimental formula instead of n=2, 2) and the pertinent reference strength for high strain hardening material like BS4360 steel is ultimate strength, $\sigma_{u}$ and for material like A533B steel is ultimate-flow strength, $\sigma_{u-f}$. The incompatible of the behavior of both experimental J-resistance curves using Rice's formula and CTOD-resistance curves for A533B and BS4360 steel by Gordon, et al., could be corrected using the optimal factor of revision in Rice\`s and the pertinent reference strength in J=$m_{j}$${\times}$$\sigma_{i}$${\times}$CTOD.

온도특성을 고려한 공항 저압간선의 경제적인 설계기법에 관한 연구 (A Study on the Economical Design of Airport Low-Voltage Feeder Which is considering the Temperature Character)

  • 최홍규;조계술;송영주
    • 조명전기설비학회논문지
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    • 제17권3호
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    • pp.119-126
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    • 2003
  • 공항과 같이 간선이 길게 포설될 수 있는 장소의 저압간선 굵기는 해당 케이블의 허용전류와 전력계통의 전압강하를 고려하며 결정된다. 비록 도체의 허용전류 값이 부하의 허용전류 값에 비하여 여유가 있을지라도 계통의 허용전압강하를 고려할 경우 도체의 굵기는 비교적 크게 산정될 수 있다. 이러한 경우에, 도체의 허용전류 값은 부하의 최대전류 값보다 훨씬 크게 산정될 수 있으며 상대적으로 도체에서 발생되는 열은 감소하게 된다. 도체의 최대 허용온도에 보정된 도체의 교류저항 값이 저압간선의 굵기 산정을 위한 전압강하 계산공식에 적용되어 왔으며, 도체의 저항 값은 도체의 실제 온도상승 값이 적용된 저항 값에 비하여 크다 본 연구는 도체의 실제 온도상승 값이 보정된 도체의 저항 값을 적용하여 저압간선 굵기 선정 설계 실무에 적용할 수 있도록 일반적인 계산 방식에 비하여 오차가 적은 경제적인 설계 방식을 연구하였다.