• 전기의세계
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• 제27권6호
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• pp.69-75
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• 1978

Diffusion processes of boron, phosphorus, and arsenic into silicon have been investigated using a new diffusion source called "spin-on source". Diffusion coefficients of these impurities have been calculated from the experimental results and are compared with the published values. Reasonable agreements have been found between the calculated and the published values. From this study, it is concluded that the spin-on source can be used as the diffusion source for integrated circuit fabricaticon.ricaticon.

• 한국운동역학회지
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• 제17권2호
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• pp.83-91
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• 2007

This experiment studied the change in a human's control of his or her static posture by analyzing the stabilogram diffusion and, by using the said study, evaluated the control ability of different groups with different experiences. The postures had a rising requirement of heel-rise according to three conditions: heel-toe, ball, toe; the groups were divided into dance major student and non-dance majors. The results of the critical points according to posture did not show a direct relation with the change in postures that had a rising requirement of heel-rise. The diffusion coefficient(D) had greater stochastic activity for short-term regions that utilize open-loop controls without feedback than for long-term regions that used closed-loop controls with feedback to maintain balance. The directional results of the body undergoing disturbance showed that A/P direction's diffusion coefficient (D) was larger than that of M/L direction. Both feet's planar diffusion coefficients were a linear combination of the diffusion coefficients calculated for the x and y axis. In studying the different abilities to control posture between a dance major student and a non-dance majors, a comparison of open-loop control's diffusion coefficient(D) was effective, and dance major student had superior control ability to that of non-dance majors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.85-90
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• 1993

This study was performed for the purpose of obtaining the fundamental data to establish the criterion of concrete deterioration and presuming steel corrosion of concrete structures under the environment of seawater. It was exposed in seawater for 1 year that steel was embedded in the concrete specimen. The diffusion coefficients of concrete, corrosion potential and steel corrosion were considered. The results show that corrosion potential is reduced according to steel corrosion and corrosion area ratio is correlative with diffusion coefficients of concrete.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1402_1403
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• 2009

The electron transport coefficients in hydrogen molecular is calculated over the range of E/N values from 0.01 to 300 Td and at temperature state of 77K, 293K and 300K by Boltzmann equation method. The results gained that the values of the electron transport coefficients such as the electron drift velocity, the electron ionization coefficients, longitudinal diffusion coefficients consisted with the results of measured and calculated for a ranage of E/N.

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.593-606
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• 2008

In this study, data on radionuclide migration and retardation processes in the engineered and natural barriers of High-Level Radioactive Waste (HLW) repository have been reviewed and compiled for use in the performance assessment of a HLW disposal system in Korea. The status of the database on radionuclide migration and retardation that is being developed in Korea is investigated and summarized in this study. The solubilities of major actinides such as D, Th, Am, Np, and Pu both in Korean bentonite porewater and in deep Korean groundwater are calculated by using the geochemical code PHREEQC (Ver. 2.0) based on the KAERI-TDB(Korea Atomic Energy Research Institute-Thermochemical Database), which is under development. Databases for the diffusion coefficients ($D^b_e$ values) and distribution coefficients ($K^b_d$ values) of some radionuclides in the compacted Korean Ca-bentonite are developed based upon domestic experimental results. Databases for the rock matrix diffusion coefficients ($D^r_e$ values) and distribution coefficients ($K^r_d$ values) of some radionuclides for Korean granite rock and deep groundwater are also developed based upon domestic experimental results. Finally, data related to colloids such as the characteristics of natural groundwater colloids and the pseudo-colloid formation constants ($K_{pc}$ values) are provided for the consideration of colloid effects in the performance assessment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.979-982
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• 2007

The effect of a scattering wall surfaces on sound diffusion can be assessed by determining the scattering and diffusion coefficients in the laboratory. However, the sound field in a concert hall including scattered reflections is different from the laboratory measurement condition. Therefore, there is a need for objective investigation of diffusion in real sound fields. In this paper, possible acoustical parameters of in-situ measurements are discussed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.793-796
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• 2001

Physical properties of concrete, Such as, compressive strength, permeable pore and penetration depth of chloride ion were investigated. And to investigate the effect of containing GGBF in concrete, the diffusion coefficient of chloride was measured through an electro- migration test. The diffusion coefficient of chloride was decreased with increase of replacement ratios of GGBF when compared to OPC. Relation coefficients between physical properties of concrete and diffusion coefficient of chloride were more than 0.9.

• 대한수학회보
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• 제35권4호
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• pp.689-700
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• 1998

We consider an infinite dimensional dynamical system what is called Lattice Dynamical System given by a discrete nonlinear diffusion equation. By assuming the nonlinearity to be a general nonlinear function with mild restrictions, we show that as the diffusion parameter changes the stationery state of the given system undergoes bifurcations from the zero state to a bounded invariant set or a 3- or 4-periodic state in the global phase space of the given system according to the values of the coefficients of the linear part of the given nonlinearity.

• Macromolecular Research
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• 제12권1호
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• pp.26-31
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• 2004

Using gravimetry, we have studied the diffusion of water into sulfonated polystyrene ionomers. Diffusion coefficients were calculated from Fick's equation. The water sorption was found to be dependent on the ion content (3.6-11 mol％) and the nature of the cation (H, Na, Li, or Zn). The sorption kinetics indicates a slight deviation from Fickian behavior. We used the analytical solution of Fick's equation to evaluate the concentration profiles, which are in good agreement with the experimental results.

• 응용통계연구
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• 제23권2호
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• pp.383-392
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• 2010

확산모형은 최근 금융현상의 연구 등에 자주 사용되는 모형이다. 본 연구에서는 확산모형의 추정에서 중요한 역할을 하는 전이확률밀도를 구하는 방법과 이를 급수전개 방식으로 근사하는 기존 연구들을 검토하여 보고, 급수전개법에서의 계수를 손쉽게 구할 수 있는 방법을 고려하게 된다. 급수전개법 계산과정에서 중요한 허밋다항식에 딘킨연산자를 반복적으로 적용하는 과정을 손쉽게 계산할 수 있는 알고리즘을 제안한다.