• Title/Summary/Keyword: maximum density

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The Effects of Starch as a Retarder in Soil Cement Mixtures (지연제로서 전분이 시멘트혼합토에 미치는 영향)

  • 김재영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.18 no.3
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    • pp.4163-4170
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    • 1976
  • This study was conducted to investigate the effect of starch as a retarder on the maximum dry density and the unconfined compressive strength of soil cement mixtures for varied starch contents (0-3%), cement contents (3-12%), and delay times (0-6hrs) in four soils. The experimental results obtained from maximum dry density and unconfined compressive strength tests are as follows: 1. Maximum dry density and unconfined compressive strength were increased greatly in soil cement mixtues rwhen starch was added as retarder but their value schanged according to soil varieties. 2. Maximum dry density showed at about 0.5 percent to 1.0 percent of starch in KY soil and about 2.0 percent to 2.5 percent in SS soil when delay time was changed in 2.4, and 6 hours in compaction test. 3. The larger content of cement was, the bigger effects of maximum dry density and compressive strength were in soil cement. mixtures. 4. As delay time changed 2.4, and 6 hours in compaction test, 7-day unconfined compressive strength showed the biggest value at about 0.5 percent of starch in KY soil and 2.0 percent in SS soil, and the maximum value of 28-day unconfined compressive strength showed at about 0.5 percent in KY soil and 1.5 percent in SS soil.

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On Relationship between Maximum Standing Crop and Species Density in the Herbaceous Vegetaton of West Central Korea (한반도 중서부 초본식생에 있어서의 최대현존량과 종밀도와의 관계에 대하여)

  • 오규칠
    • Journal of Plant Biology
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    • v.26 no.3
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    • pp.161-171
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    • 1983
  • To test whether the Grime's model on relationship between maximum standing crop plus litter (350~750g/$m^2$) and species density (10~30/0.25$m^2$) fit well or not, a total of 52 samples, with 4 replicate plots (0.5m$\times$0.5m each) per sample, was collected from various forests, grass lands and coastal salt marshes in midwestern part of central Korean peninsula from September to October in 1982. The result agrees well with the model for grass lands salt marshes, that is, shape of curve for the maximum standing crop (minus litter) against species density indicates normal distribution. The number of species was 11 for the grassland and 7 for the salt marshes within the range of 300g to 700g per square meter for the maximum standing crop. In forest stands, however, as the maximum standing crop of herbs increased the species density decreased. The Grime's model does not seem to fit with the resutls on forest stands of this study. It is examined further the relationships among the maximum standing crop, species density and eleven soil properties, and the possible cause of this discrepancy was disscused.

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A Robust Estimation for the Composite Lognormal-Pareto Model

  • Pak, Ro Jin
    • Communications for Statistical Applications and Methods
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    • v.20 no.4
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    • pp.311-319
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    • 2013
  • Cooray and Ananda (2005) proposed a composite lognormal-Pareto model to analyze loss payment data in the actuarial and insurance industries. Their model is based on a lognormal density up to an unknown threshold value and a two-parameter Pareto density. In this paper, we implement the minimum density power divergence estimation for the composite lognormal-Pareto density. We compare the performances of the minimum density power divergence estimator (MDPDE) and the maximum likelihood estimator (MLE) by simulations and an example. The minimum density power divergence estimator performs reasonably well against various violations in the distribution. The minimum density power divergence estimator better fits small observations and better resists against extraordinary large observations than the maximum likelihood estimator.

Thermohydrodynamic Lubrication Analysis of High Speed Journal Bearing Considering Variable Density and Specific Heat (변화하는 밀도와 비열을 고려한 고속 저어널 베어링의 열유체 윤활해석)

  • 전상명;장시열
    • Tribology and Lubricants
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    • v.17 no.4
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    • pp.297-306
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    • 2001
  • Under the condition of variable density and specific heat, maximum pressure, maximum temperature, bearing load, friction and side leakage in high-speed journal bearing operation are examined within some degree of Journal misalignment. The results are compared with the calculation results under the conditions of constant density and specific heat, and variable density and constant specific heat. It is found that the condition of variable density and specific heat play important roles in determining friction and load of Journal bearing at high speed operation.

Maximum Stem Number and Mortality Model for Even-Aged Pinus Densiflora Stand in Kangwon-Province, Korea (강원도지방(江原道地方) 소나무 동령임분(同齡林分)의 최대임목본수(最大林木本數) 및 고사(枯死)모델)

  • Lee, Woo-Kyun;Seo, Jeong-Ho;Bae, Sang-Won
    • Journal of Korean Society of Forest Science
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    • v.89 no.5
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    • pp.634-644
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    • 2000
  • Sterba's theory that stem number maintaining maximum basal area per ha is maximum stem number of a stand, had been applied to data from 103 temporary plots in even-aged Pinus densiflora stands in Kangwon province, Korea and a maximum stem number and mortality model was prepared. DBH growth model which estimates dbh with the independent variables of stem number per ha and dominant height shows the good statistical performance, and explains well differences in dbh growth that would be caused by stem number per ha and dominant height. Basal area model derived from dbh growth model also explains well differences in basal area according to stem number per ha and dominant height. The maximum stem number curve, which is derived from stem number per ha at maximum basal area for dominant height and dbh, represents well the upper range of stem number per ha observed. And maximum stand density index derived from the maximum stem number model for dbh could be used for the index of maximum potential density of a stand. The maximum stem number model and maximum stand density index in this study were not based on stand data with maximum density but based on the temporary data from stands with various density. This maximum stem number model can be applied to the estimation of mortality and maximum potential volume.

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Holding Strength of Screws in Domestic Particleboard and Medium Density Fiberboard (I) - Optimum Pilot Hole Diameter - (국산 파티클보오드와 중밀도 섬유판의 나사못 유지력(I) - 최적 예비구멍 직경 -)

  • Lee, Phil-Woo;Park, Hee-Jun;Han, Yu-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.19 no.3
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    • pp.27-34
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    • 1991
  • Screw withdrawal test was carried out on the face and edge of domestic particleboard and medium density fiberboard in order to evaluate optimum pilot hole diameter. The obtained results were as follows: 1. Maximum withdrawal strengths on the face and edge of particleboard were obtained with pilot hole diameters at about 50% of root diameters of screw. 2. Maximum withdrawal strength on the face and edge of medium density fiberboard were obtained with pilot hole diameters that were about 60% and 50% of root diameters of screw, respectively. 3. Withdrawal strength showed about 91% of maximum withdrawal strength when pilot holes were not pre bored at particleboard. but when pilot holes at 90% of root diameter of screw withdrawal strength showed about as 51.3% of maximum withdrawal strength. 4. Withdrawal strength showed about 88% of maximum strength when pilot holes were not used, but withdrawal strength indicated 55.4% of maximum strength in case of 90% of root diameters of screw. 5. Maximum withdrawal strength on the face of particleboard was about 70.5% higher than that of the edge, and however medium density fiberboard was about 19.6% higher than that of the edge.

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Ambiguity of Minimum Strain Energy Density Criterion and Maximum Minimum Strain Energy Density Criterion (최소 변형에너지 밀도 기준의 모호성과 최대 극소 변형에너지 밀도 기준)

  • Gu, Jae-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.7
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    • pp.1155-1162
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    • 2001
  • Sihs minimum strain energy density criterion(SED) often used in the mixed mode problem has the ambiguity of the choice of minimum values. In this paper, as the method to solve the problem of SED, maximum minimum strain energy density criterion is proposed that the crack propagates in the direction of having the maximum among the minimum values of modified strain energy density factor(MS), i.e., sign($\sigma$(sub)$\theta$).Smin.

A Study of Magnetic Properties of 410L Stainless Steel for Manufacture of ABS Sensor Ring (410L 스테인레스 강의 ABS센서 링 제조를 위한 자기적 특성에 관한 연구)

  • Yang, H.S.;Kwak, C.S.;Rhim, J.K.
    • Journal of the Korean Society for Heat Treatment
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    • v.11 no.4
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    • pp.241-246
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    • 1998
  • It is well known for 410L ferritic stainless steel powder to applicate a sensor ring in anti-lock brake system of automobile, several studies, because of its excellent magnetic properties. This study was carried out to investigate the magnetic properties such as the maximum magnetic induction, coercivity and maximum permeability of the materials with functions of sintering density, time and temperature, and concluded as follows: 1. Sintering under the circumstances of Ar gas and the temperature of $1250^{\circ}C$ for 60min, showed that nitrogen was increased, whereas carbon and oxygen decreased in quantities. 2. Both maximum magnetic induction value of 4700Gauss and permeability of 200 were obtained at the maximum sintering density of $6.89g/cm^2$. Here, the properties showed a linear increasement with increasing the sintering density. 3. Coercivity sharply decreased with incresing the sintering density and reached to 7.6Oe at the maximum sintering density of $6.89g/cm^2$.

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ON HELLINGER CONSISTENT DENSITY ESTIMATION

  • Nicoleris, Theodoros;Walker, Stephen-G.
    • Journal of the Korean Statistical Society
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    • v.32 no.3
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    • pp.261-270
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    • 2003
  • This paper introduces a new density estimator which is Hellinger consistent under a simple condition. A number of issues are discussed, such as extension to Kullback-Leibler consistency, robustness, the Bayes version of the estimator and the maximum likelihood case. An illustration is presented.

The optimum geometric design of stators for brush less DC linear motors (브러시없는 직류 선형 모터의 고정자 형상 최적 설계)

  • 최문석;김용일;이상락
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.1173-1176
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    • 1995
  • We design and analyze two type stators for brushless DC linear motors by the experiment and the computational analysis. For a U-shape stator, the maximum manetic flux density by the finite element method(FEM) is large than that by the experiment by 1.0~2.2%. The result by the FEM is so accurate that it can be applied to the geometric design for the optimization. To increase the maximum magnetic flux density, we suggest an improved stator and analyze it by the 3-D and 2-D models. The maximum magnetic flux density of the improved stator is large than that of the U-Shape stator by 2.7%. Considering the size of the improved stator and maximum magnetic flux density, we determine that the optimized thickness is 5mm for a given specification.

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