• 제목/요약/키워드: Experimental formula

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사용반복하중에 대한 철근콘크리트 보의 피로거동 (Fatigue behavior of RC Beams under High Cycle Loading)

  • 강보순;황성춘
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 I
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    • pp.499-503
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    • 2001
  • Fatigue behavior of reinforced concrete (RC) elements has been experimentally and analytical investigated. Fatigue behavior influenced by longitudinal reinforcement ratio, strength of concrete and load ratio P/sub u//P/sub o/. The purpose of these studies is to propose an empirical formula for fatigue behavior on basis of experimental results. Also an analytical method to predict the crack propagation of RC beams has been developed based on the relationships between bond stress and slip.

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Manning's Roughness Factor in Alluvial Channels

  • Jun, Byong-Ho
    • Korean Journal of Hydrosciences
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    • 제1권
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    • pp.49-60
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    • 1990
  • Manning's roughness factor to flow in sand-bed channels may be divided into the grain roughness factor nd the form roughness factor. The grain roughness factor may be dedermined by using Keulegan's formula. By using available experimental data, it was found there is a unique relationship between the form roughness and the hydraulic radius to sediment particle size ratio for a given value of the Froude number. The form roughness and the bed form may be determined by using this unique relationship. The technique for engineering applications of the results appears to be quite simple.

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경(硬)갚셀제(劑)의 흡습(吸濕)에 관(關)한 연구(硏究) (Studies on Water Vapor Absorption through Hard Gelatin Capsules)

  • 박종훈
    • Journal of Pharmaceutical Investigation
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    • 제3권3호
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    • pp.16-19
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    • 1973
  • Stability is impaired in capsules in which there is a transfer of water vapor from capsule to the contents of the capsules. The water vapor transfer between AEA-coated capsules and corn starch, magnesium trisilicate in the closed container was examined. Experimental eguilibrium relative humidity after water vapor transfer and estimated values calculated from a formula of these substances were in close agreement with each other.

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고온수열된 고강도콘크리트의 압축강도에 관한 실험적 연구 (An Experimental Study on the Compressive Strength of High Strength Concrete Heated High.)

  • 강병희;오창희
    • 한국화재소방학회논문지
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    • 제3권2호
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    • pp.3-10
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    • 1989
  • The results on high strength concrete by heating high are as follows: 1. High strength concrete appeared an estimated 5.5% higher than ordinary concrete in the central temperature of specimens by heating. 2. High strength concrete is higher than ordinary concrete in the decreased width of the ratio on the residual compressive strength by heating high. According to heating temperature and time, the inferred formula of compressive strength on high strength concrete showed: Fc=-0.53Te -2.4Ti +748.4

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콘크리트 탄성계수 추정의 미시역학적 모델 (Micromechanical Models for the Evaluation of Elastic Moduli of Concretes)

  • 조호진;송하원;변근주
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.383-391
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    • 1997
  • The prediction of effective properties of heterogeneous material like concrete is of primary importance in design or analysis. This paper os about micromechanice-based evaluation of elastic moduli of concretes considering composite material behavior. In this study, micromechanixe-based schemes for the effective elastic modui of the lightweight foamed concrete and the normal concrete are proposed based on averaging techniques using a single-layered inclusion model and a multi-phase and multi-layered inclusion model. respectively, For the verification's sake, elastic moduli evaluated in this study are compared with experimental data and results by existing formula.

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사용피로하중에 대한 철근 콘크리트 구조물의 균열특성 (Crack Behavior of RC Structures under High Cycle Loading)

  • 강보순
    • 한국철도학회논문집
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    • 제8권6호
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    • pp.495-499
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    • 2005
  • Fatigue behavior of reinforced concrete(RC) elements has been experimentally and analytical investigated. Fatigue behavior is influenced by a longitudinal reinforcement ratio, strength of concrete and a load ratio Pu/Po. The purpose of this study to propose an empirical formula for the fatigue behavior on the basis of experimental results. Also an analytical method to predict the crack propagation of RC beams has been developed based on the relationships between bond stress and slip.

Stray field를 고려한 원형 마이크로스트립 공진기 해석 (An Analysis of Circular Microstrip Resonator Considering Stray Fields)

  • 박두석;홍의석
    • 대한전자공학회논문지
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    • 제26권12호
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    • pp.1934-1939
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    • 1989
  • The circular microstrip resonator which can be exactly performed with theoretical resonant frequency using the conception of dynamic effective relative dielectric constants is analyzed in this paper. The formula of exact resonant frequency of resonator, in this study, is estabilished by effective resonator dimension and dynamic relative dielectric constant. The measurement of transmission type circular resonator which fabricated by AL2O3 and Epsilam-10 is to prove that the experimental results are more agreed a well with the simulated values by this new method than the simple resonator model.

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Mutual Inductance of the Non-Coaxial Coils in Coil Gun

  • 김기봉
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.120-123
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    • 1994
  • The purpose of this paper is to describe the mutual inductance between two non-coaxial circular coils in coil gun. As being in many electromagnetic applications, one of them is fixed and the other one is moving and, being not supported, its axis may not coincide with the axis of the fixed coil. This paper presents a method for the calculation of the mutual inductance in case of non-coaxial coupled coils, the characteristics of this inductance and experimental results. For the computation, the complete elliptic integrals formula and mesh matrix technique were introduced. This method enables accurate results from relatively simple procedure and calculation program.

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지하철 통과 시 지반소음 예측 (Estimation of Ground-Borne Noise Generated by Subway)

  • 김재철;구동회;이준석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.1448-1453
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    • 2008
  • This paper deals with the estimation methods of ground-borne noise generated by subway. Generally, numerical method using by ground model is used to prediction of ground borne noise. However, this method is needed a lots of time to make an analysis and model. In this paper, we describe empirical formula that is based on experimental data for subway and estimate the ground-borne noise propagated from underground station that is builded in the near future to building.

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(-)-Hydroxycitrate를 이용한 비만 여성의 체중 조절 프로그램 실시 및 효과 평가에 관한 연구(I) (The Effect of (-)-Hydroxycitrate on Weight Control Program in Obese Women -I : Effect on Anthropometric Parameters-)

  • 문수재
    • Journal of Nutrition and Health
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    • 제30권2호
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    • pp.155-169
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    • 1997
  • This study investigated the effect of weight control by using the commercial appetite suppressant ((-)-hydroxycitric acid(HCA) formula) and nutrition education on 72 obese women over a period of 8 weeks. During the study it conducted nutritional education for women to control their weight, thus analyzed their changes in anthropometric variables. All obese women were randomized in a double-blind method to consume either HCA(HCA group : experimental group) or placebo(placebo group : control group). Two groups were also divided randomly into 2 groups combined with commercial formula diet in 1 meal a day(HD group and PD group : HCA + gormula diet and placebo + formula diet) or not(HO group and conducted with 4 groups(HD, HO, PD, and PO group). All subjects were assigned to consume 800-1500kcal/d balanced diet which is 500kcal less than their usual energy requirement. To evaluate the effect of the weight control program, weight, percent of body fat, waist and hip circumferences, and 5 skinfold thickness were measured up to 5 times in all obese women. The mean weight of the subjects at the onset of the study was 76.5$\pm$10.6kg. The mean body mass index(BMI) wa 30.1$\pm$3.8 and it was in the upper 5 percentile of mean BMI of Korean women. At the end of the program, mean weight loss was 3.5kg after 2 weeks(p<0.001), and 5.8kg after 4 weeks(p<0.001). The waist, hip ratio(WHR) and skinfold thickness measurements of biceps, triceps, subscapular, suprailiac and abdominum showed significant reduction over the entire study period(p<0.05). These outcome were evaluated by effect of nutritional education and counselling. The reduction of % of body fat was significantly different among the 4 groups. Women who administrated HCA demonstrated more change in weight, BMI than the placebo group. There was also significant reduction in body composition (% of body fat, WHR, and skinfold thickness) than the other groups. The HD group which was administrated HCA combined with formula diet was more decreased than other groups. It showed that this program using commercial HCA and formula diet induced not only a change in weight but also a change in body composition. The outcome of this study suggests that HCA has a more effctive change on weight control which is carried out with nutritional education and counselling.

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