• Journal of the Korean Geotechnical Society
• /
• v.20 no.9
• /
• pp.47-56
• /
• 2004

A new fragmentation model, called the GRS (the generation model of weathered residual soils) model, was proposed in this study, This model could identify the formation of a residual soil. This model is based on the phenomena that as the soil was weathered more highly, soil particles were smaller and pores were more expanded simultaneously. The possibility of fragmentation, $P_F,$ which was based on the fractal theory, was introduced in this model. There were some fundamental notions in the GRS model that soil particles were generated as the rock is fragmented, and the fragmentation of the rock was performed step by step. The $P_F,$ of the rock was not constant at each fragmentation steps. As a result of application on the GRS model, there were more residue where $P_{Fi}s$ were small at any particle size. There was a S-shape of PSD curve at the concave shape of $P_{Fi},$ and the PSD curve goes to a gaped graded curve at the convex shape of $P_{Fi}.$ The shape of PSD curve was concave in the case of small $P_{Fi}s.$ The value of $P_{Fi}$ increased with the coefficient of uniformity $(C_u)$ and the fragmentation fractal dimension $(D_r),$ but had no relation with the coefficient of gradation $(C_C)$.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.5
• /
• pp.471-482
• /
• 2016

In this study, we focused on a speed-up of KIESSI-3D program, which is based on FE-IE techniques, by introducing a p-version dynamic infinite element method. In order to evaluate performance of the KIESSI-3D, numerical analyses for eight real-scale SSI problems are carried out. We considered three types of KIESSI-3D numerical models whose radii of near-field soil region($r_0$)are 1.2, 1.5, and 3.0 times of basemat radius of structure(R). In addition, SSI analyses using the SASSI2010 program are carried out used for comparison of accuracy and runtime against those of the KIESSI-3D. Numerical results show that the KIESSI-3D model of $r_0=1.2R$ is enough to give accurate solution. In view of the computing speed, the new KIESSI-3D was up to 25 times faster than the old KIESSI-3D.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.14 no.1
• /
• pp.214-224
• /
• 1990

A "two-fluid" model using thermal eddy diffusivity concept and Lumley's drag reduction theory, is proposed to analyze heat transfer of the turbulent dilute gas-particle flow in a vertical pipe with constant wall heat flux. The thermal eddy diffusivity is derived to be a function of the ratio of the heat capacity-density products .rho. over bar $C_{p}$ of the gaseous phase and the particulate phase and also of the ratio of thermal relaxation time scale to that of turbulence. The Lumley's theory dictates the variation of the viscous sublayer thickness depending on the particle loading ratio Z and the relative particle size $d_{p}$/D. At low loading ratio, the size of viscous sublayer thickness is important for suspension heat transfer, while at higher loading, the effect of the ratio .rho. $_{p}$ over bar $C_{p}$$_{p}$/ .rho. $_{f}$ over bar $C_{p}$$_{f}$ is dominant. The major cause of decrease in the suspension Nusselt number at lower loading ratio is found to be due to the increase of the viscous sublayer thickness caused by the suppression of turbulence near the wall by the presence of solid particles. Predicted Nusselt numbers using the present model are in satisfactory agreements with available experimental data both in pipe entrance and the fully developed regions.

• Journal of Korean Institute of Industrial Engineers
• /
• v.26 no.3
• /
• pp.220-226
• /
• 2000

The problem (P) of optimizing a linear function $d^Tx$ over the set of efficient points for a multiple objective linear program (M) is difficult because the efficient set is nonconvex. There are some interesting properties between the objective linear vector d and the matrix of multiple objectives C and those properties lead us to establish criteria to solve (P) with a linear program. In this paper we investigate a system of the linear equations $C^T{\alpha}$ = d and construct two linearly independent positive vectors u, v such that ${\alpha}$ = u - v. From those vectors u, v, solving an weighted sum linear program for finding an efficient extreme point for the (M) is a way of getting an optimal solution of the problem (P). Therefore the theorems presented in this paper provided us an easy way of solving nonconvex program (P) with a weighted sum linear program.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2023.11a
• /
• pp.165-166
• /
• 2023

BCMS의 변경관리에 대한 요구사항은 ISO 22301 구성체계의 기획단계인 6.3 변경의 기획에서 수행하고, 기업재난관리표준 구성체계에서 기획단계인 3.5.5 문서화된 정보에서 수행하도록 규정하였으며, 이는 모두가 P-D-C-A 운용 모델의 Plan 단계에 해당된다. 이러한 구성체계는 BCP를 최초에 수립하는 단계에서는 적합하지만, BCP가 수립(제정)되어 운용단계에서 발생되는 변경사항을 처리하는데는 많은 문제점이 도출된다. 따라서 재난 및 안전관리 분야에 해당하는 유사제도의 요구사항을 대상으로 비교분석을 통하여 도출된 개선방안을 연구결과로 제시하고자 한다. BCP를 수립하는 과정에서 발생하는 보완사항은 변경관리 절차에 포함하지 않고, BCP가 수립되어 운용단계에서 발생되는 변경사항만 변경관리 절차에 포함하여 관리하며, P-D-C-A 운용 모델의 Act 단계에서 수행하는 것이 적합하다.

• Reproductive and Developmental Biology
• /
• v.29 no.1
• /
• pp.43-48
• /
• 2005

To search of a new porcine pheromonal odorants for biostimulation control system technologies to offer a potentially useful and practical way to improve reproductive efficiency in livestock species, the holographic quantitative structure activity relationship (HQSAR) model between odorants, 2-phenoxytetrahydrofurane (A), 2-cyclohexyl-oxytetrahydrofurane (B), derivatives and binding affinity constants (p[Od.]/sub 50/) for porcine odorant-binding protein (pOBP) as receptor of pig pheromones were derivated and disscused. The binding affinity constants of cyclohexyl substituents (A) for pOBP were higher (A>B) than that of phenyl substituents (B). It was revealed that the optimum HQSAR model XI using PLS analyses had a fragment length (5∼8) with chirality at 5 components and hologram length 97 bin, which had a cross-validated q²(predictablities) of 0.916, and a conventional correlation coefficient r² (fitness) of 0.988, respectively. From the atomic contribution, the C3 and C5 atom in 2-oxyfuryl group contributed to binding affinity constants, whereas the central carbon atom in tert-butyl group on the cyclohexyl ring and the C4 atom of furyl group parts showed no contribution.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.2
• /
• pp.91-101
• /
• 2011

In this study, a new design method of Pile-Bent structure considering plastic hinge was proposed on the basis of the beam-column model. To obtain the detailed informations, the optimized cross-section ratio between column and pile was analyzed to induce the plastic hinge at the joint section between the pile and column. Base on this study, the optimized diameter ratio of pile and column can be obtained below the inflection point of the bi-linear curve depending on the relations between column-pile diameter ratio ($D_c/D_p$) and normalized lateral cracking load ratio ($F/F_{Dc=Dp}$). Moreover, through comparisons with field cases to find out in-depth limit in which minimum concrete-steel ratio could be applied, in-depth limits ($L_{As=0.4%}$) normalized by the pile length ($L_p$) proportionally decrease as the pile length ($L_p/D_p$)increases up to $L_p/D_p=17.5$, and beyond that in-depth limit converges to a constant value (${\simeq}0.3$).

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10a
• /
• pp.724-726
• /
• 1998

본 논문에서는 방대한 양의 데이터를 실시간으로 처리하기 위한 병렬 디지털 신호처리시스템을 제안한다. 버스와 메모리의 구조가 다른 네 가지 신호처리부 모델을 제안하고 그들의 성능을 분석한다. 신호처리부의 분석은 소나 알고리즘을 실행하는데 소요되는 하드웨어 지연시간과 버스 지연시간의 합을 척도로 한 성능 분석과 보드의 복잡도를 비교하는 방법을 통하여 이루어졌다. 성능분석한 결과, 지역 메모리와 공유 메모리를 함께 사용하는 모델이 가장 효율적인 것으로 나타났다.

• Journal of Aquaculture
• /
• v.7 no.4
• /
• pp.239-249
• /
• 1994

This study was conducted to elucidate mixing characteristics of the media to dertermine hydraulic model parameters of the three phase fluidized bed for the water quality management of aquaculture. The volume and H/D ratio of the reactor were 1.76 Liter and 10.9, respectively. The experimental results showed that variance $(\sigma^2)$ and dispersion number $(D/{\mu}L)$ were above 0.47 and $0.35\~\infty$, respectively. Therefore, the condition of the reactor was almost ideal complete mixing. The dependence of the overall oxygen-transfer coefficient $(K_{La})$ on each experimental variables through a multple linear regression was given by the following equation ; $$K_{La}\;=\;44.9(D_i/D_c)^{-0.4611}\;A_f^{0.8622}\;C_m^{-0.0746}\;d_p^{-0.4302}$$

• Korean journal of applied entomology
• /
• v.56 no.4
• /
• pp.387-394
• /
• 2017

Temperature-dependent oviposition model and life table parameters of Paromius exiguus (Distant), the causal agent of 'pecky' rice grain were examined at eight constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5, and $35{\pm}^{\circ}C$) and a photoperiod of 14:10 (L:D) h. Unit functions of the oviposition model were developed and life table parameters were estimated. The longevity of P. exiguus adults decreased with increasing temperature (123.8 days at $17.5^{\circ}C$ and 23.6 days at $32.5^{\circ}C$). Total fecundity was highest at $30^{\circ}C$ (585.2 eggs/female) and lowest at $17.5^{\circ}C$ (21.5 eggs/female). In order to develop a temperature-dependent oviposition model, adult aging-rate, temperature-dependent fecundity, age-specific survival rate, and age-specific cumulative oviposition rate equations were estimated. All unit equations ($r^2=0.92{\sim}0.98$) except for the temperature-dependent fecundity equation ($r^2=0.83{\sim}0.85$), described oviposition characteristics of P. exiguus adequately. Life table parameters of P. exiguus were estimated at various constant temperatures. Net reproduction rate ($R_0$) was highest at $30^{\circ}C$ (118.21). Mean generation time (T) was shortest at $32.5^{\circ}C$ (32.99 days) and doubling time (Dt) was shortest at $30^{\circ}C$ (5.69 days). The highest values of intrinsic rate of increase ($r_m$) and finite rate of increase (${\lambda}$) were 0.122 and 1.129 at $30^{\circ}C$, respectively.