• Title/Summary/Keyword: Uniform distribution

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Resistance distribution in large area thin film type SFCLS (박막형 대면적 초전도 한류소자에서의 저항 분포)

  • 김혜림;최효상;현옥배
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.89-93
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    • 2002
  • We investigated the resistance distribution n 4"diameter SFCLS. $YBa_2CU_3O_7$ films coated in-situ with a gold layer were patterned into 3 mm wide 142 cm long meander lines by Photolithography. The limiters were tested with simulated fault currents. The resistance was uniform all over the film except at the edge. At lower source voltages, CFCLs did not quench simultaneously and the resistance distribution was less uniform. Compared with 2" diameter SFCLS 4" SFCLS had similar values and time dependence of resistivity at similar electric fields The resistance distribution was more uniform in 4" SFCLS. The area at the edge where the distribution was not uniform was around 3 mm wide in SFCLs of both sizes. The experimental results were quantitatively explained with a heat transfer concept.

UNIFORM DISTRIBUTIONS ON CURVES AND QUANTIZATION

  • Joseph Rosenblatt;Mrinal Kanti Roychowdhury
    • Communications of the Korean Mathematical Society
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    • v.38 no.2
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    • pp.431-450
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    • 2023
  • The basic goal of quantization for probability distribution is to reduce the number of values, which is typically uncountable, describing a probability distribution to some finite set and thus to make an approximation of a continuous probability distribution by a discrete distribution. It has broad application in signal processing and data compression. In this paper, first we define the uniform distributions on different curves such as a line segment, a circle, and the boundary of an equilateral triangle. Then, we give the exact formulas to determine the optimal sets of n-means and the nth quantization errors for different values of n with respect to the uniform distributions defined on the curves. In each case, we further calculate the quantization dimension and show that it is equal to the dimension of the object; and the quantization coefficient exists as a finite positive number. This supports the well-known result of Bucklew and Wise [2], which says that for a Borel probability measure P with non-vanishing absolutely continuous part the quantization coefficient exists as a finite positive number.

Effects of friction variability on a rolling-damper-spring isolation system

  • Wei, Biao;Wang, Peng;He, Xuhui;Zhang, Zhen;Chen, Liang
    • Earthquakes and Structures
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    • v.13 no.6
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    • pp.551-559
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    • 2017
  • A large number of isolation systems are designed without considering the non-uniform friction distribution in space. In order to analyze the effects of non-uniform friction distribution on the structural response of isolation system, this paper presented a simplified rolling-damper-spring isolation system and analyzed the structural responses under earthquakes. The numerical results indicate that the calculation errors related to the peak values of structural acceleration, relative displacement and residual displacement are sequentially growing because of the ignorance of non-uniform friction distribution. However, the influence rule may be weakened by the spring and damper actions, and the unreasonable spring constant may lead to the sympathetic vibration of isolation system. In the case when the friction variability is large and the damper action is little, the non-uniform friction distribution should be taken into consideration during the calculation process of the peak values of structural acceleration and relative displacement. The non-uniform friction distribution should be taken into full consideration regardless of friction variability degree in calculating the residual displacement of isolation system.

Effects of an Outlier for Estimators in a Uniform Distribution

  • Woo, Jung-Soo;Lee, Chang-Soo;Lee, Jang-Choon
    • Communications for Statistical Applications and Methods
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    • v.5 no.3
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    • pp.837-845
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    • 1998
  • We shall propose several estimators and confidence intervals for the scale parameter in a uniform distribution with the presence of a unidentified outlier and obtain biases and mean squared errors for their proposed estimators. And we shall numerically compare the performances for the proposed several estimators of the sclae parameter. Also, we shall compare lengths of confidence intervals of the scale parameter in a uniform distribution through Monte Carlo methods.

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Simulation of Material Properties of Amorphous Carbon Nitride with Non-uniform Nitrogen Distribution

  • Lu, Y.F.;He, Z.F.
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.3
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    • pp.1-6
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    • 2001
  • A simulation method is proposed to study the amorphous structure of carbon nitride. The material properties of a non-uniform nitrogen distribution in an amorphous CN matrix can be studied. The cohesive energy of a group of randomly generated atoms can be minimized to find the relative positions of atoms. From the calculated configuration of atoms, many properties of amorphous carbon nitride can be calculated such as bulk modulus, P-V curve, sp$^3$/sp$^2$ ratio of carbon, and vibrational spectra. The calculation shows that the cohesive energy of non-uniform nitrogen distribution is lower than that of a uniform distribution. This may suggest that the regular structure of carbon nitride can at most be metastable. It is not easy to incorporate nitrogen atoms into a carbon matrix.

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Estimations for a Uniform Scale Parameter in the Presence of a Half-Triangle Outlier

  • Lee, Chang-Soo;Kim, Kee-Hwan;Park, Yang-Woo
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.3
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    • pp.959-965
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    • 2008
  • We shall propose several estimators for the scale parameter in a uniform distribution with the presence of a half-triangle outlier, and obtain mean squared errors(MSE's) for their proposed estimators. And we shall compare numerically efficiencies for proposed several estimators of the scale parameter in a uniform distribution with the presence of a half-triangle outlier in the small sample sizes.

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Prediction of Air Movement and Temperature Distribution at Different Store Methods Using 3-D CFD Simulation in Forced-Air Cooling Facility

  • Yang, G.M.;Koh, H.K.
    • Agricultural and Biosystems Engineering
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    • v.3 no.2
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    • pp.65-72
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    • 2002
  • Temperature is the most influential environment parameter which affects the quality change of agricultural products in cold storage. Therefore, it is essential to keep the uniform temperature distribution in the storage room. This study was performed to analyze the air movement and temperature distribution in the forced recirculating cold storage facility and to simulate optimum storage method of green groceries using 3-D CFD(three dimensional computational fluid dynamics) computer simulation which applied the standard $textsc{k}$-$\varepsilon$ turbulence model and FVM(finite volume method). The simulation was validated by the experimental results for onion storage and the simulation model was used to simulate the temperature and velocity distribution in the storage room with reference to the change of storage method such as location of storage, no stores, bulk storage, and pallet storage. In case of no stores, internal airflow was circulated without stagnation and consequently air movement and temperature distribution were uniform. In case of bulk storage, air movement was stagnated so much and temperature distribution of onion was not uniform. Furthermore, the inner temperature of onion roses more than the initial temperature of storage. In case of pallet storage, air movement and temperature distribution of onion were so uniform that the danger of quality change was decreased.

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Benford's Law in Linguistic Texts: Its Principle and Applications (언어 텍스트에 나타나는 벤포드 법칙: 원리와 응용)

  • Hong, Jung-Ha
    • Language and Information
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    • v.14 no.1
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    • pp.145-163
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    • 2010
  • This paper aims to propose that Benford's Law, non-uniform distribution of the leading digits in lists of numbers from many real-life sources, also appears in linguistic texts. The first digits in the frequency lists of morphemes from Sejong Morphologically Analyzed Corpora represent non-uniform distribution following Benford's Law, but showing complexity of numerical sources from complex systems like earthquakes. Benford's Law in texts is a principle reflecting regular distribution of low-frequency linguistic types, called LNRE(large number of rare events), and governing texts, corpora, or sample texts relatively independent of text sizes and the number of types. Although texts share a similar distribution pattern by Benford's Law, we can investigate non-uniform distribution slightly varied from text to text that provides useful applications to evaluate randomness of texts distribution focused on low-frequency types.

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Dilutant flow characteristics model of coarse particle suspensions with uniform size distribution

  • Ookawara, Shinichi;Ogawa, Kohei
    • Korea-Australia Rheology Journal
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    • v.15 no.1
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    • pp.35-41
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    • 2003
  • It is expected that particle size distribution of any portion obtained through screening, is of more uniform than that of the original mixture, typically following such as log-normal, Rosin-Rammler distributions and so on. In this study, therefore, a new relation between parameters of the uniform distribution and flow characteristics of the coarse particle suspensions is derived based on the continuous polydisperse model (Ookawara and Ogawa, 2002b), which is derived from the discrete polydisperse model (Ookawara and Ogawa,2002a). The derived model equation predicts a linear increase of viscosity with shear rate, viz., dilutant flow characteristics. Further, the increase of viscosity is expected to be proportional to the square of volume fraction of particles, and to show the linear dependency on density and average diameter of particles. It is also shown that the uniform distribution model includes additional term that expresses the effect of distribution width. For verification of the model, the experimental results of Clarke (1967) are cited as well as in our previous work for the monodisperse model (Ookawara and Ogawa,2000) since most parameters were varied independently in his work. It is suggested that the newly introduced term expands the applicable range compared with the monodisperse model.

An Experimental Study on the Non-Uniform Flow Distribution in the Windbox of an Oil-Fired Boiler (유류 연소 발전용 보일러에서 공기 공급 계통의 불균일성에 관한 실험적 연구)

  • Go, Young-Gun;Kim, Young-Zoo;Choi, Sang-Min
    • Journal of the Korean Society of Combustion
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    • v.11 no.1
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    • pp.1-10
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    • 2006
  • Oil-fired power plant usually uses several burners and combustion air is supplied to each burner through the complicated duct which is called windbox. A windbox should be designed to supply combustion air to each burner uniformly but, due to the complicated duct shape, flow distribution in the windbox is unbalanced and non-uniform supplies of combustion air are induced by these unbalanced flows in the windbox. These flow patterns tend to make flame unstable, increase the formation of pollutants and lower the overall combustion efficiency. To prevent these disadvantages, flow patterns in the windbox should be investigated for the uniform flow distribution. In this study, computational simulation method was used to investigate the flow distribution in a windbox and measured the velocities at the exit of burners in a real windbox and model tests to compare with CFD results. The results show two significant flow patterns. One is that the flow rates of each burner are different from each other and this means that all burners operate in different conditions of air to fuel ratio. The other is that the flow distribution at the exit of each burner is not axi-symmetric although the burner shape is axi-symmetric. Additionally some modifications of windbox shape and installation of baffles were proposed to make the uniform flow in the windox.

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