• Journal of Environmental Science International
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• v.10 no.6
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• pp.451-459
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• 2001

Adsorption characteristics of triadimefon and diniconazole(pesticide) by natural zeolite($CLI_N$) and several synthetic zeolites were Investigated. The synthetic zeolites used En this study were as follows: Faujasite synthesized from coal fly ash($FAU_F$); Zeolite synthesized from the mixture of FAU and Na-Pl synthesized from the ratio of Cheju scoria 6 to coal fly ash 4 by weight($(FAU + Na-Pl)_{SF}$); waste fluid catalytic cracking catalyst($FCC_W$). The distribution coefficient, $K_D$ and Freundlich constant, $K_F$ decreased in the fellowing sequence : $FCC_W ＞ FAU_F ＞ (FAU + Na-Pl)_{SF} ＞CLI_N$ among the zeolites. The distribution coefficient and the adsorption capacity of $(FAU + Na-Pl)_{SF}$ for pesticides were 4.4 and 2.6 times higher for triamefon, and 2.0 and 2.4 times higher for diniconazole than those of $CLI_N$, respectively.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.29-31
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• 2006

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. the ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the ${\sigma}-N_f$ relation with the maximum stress at the edge of fillet welded joint.

• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.302-307
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• 2002

The characteristics of trace metals were investigated in the sediments of the Mokpo coastal area, southwestern coast of Korea. Surface sediments were collected in September 3, 2002 after a strong rain event. The sampling sites were categorized into the inner and outer harbour based on salinity distribution and difference of trace metal concentration was evidence between these two zones. The enrichment factor (E' F) of Zn and Cr were high at the mouth of Mokpo Harbour and $E \cdot F$ of Cu was high at the east-south of Dali Island. One hundred percent of Mn and Pb samples and $40\%$ of Zn samples had E' F higher than 1 suggesting that they are accumulated in the entire outer of Mokpo Harbour. Trace metals appeared to be accumulated in the inner harbour by input of sediments in the discharged freshwater from Young-San River during strong rainfall whereas they were influenced by natural sedimentation and human activities in part.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.401-408
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• 2009

This study is performed to check the three dimensional characteristics of residual stress in the dissimilar metal weld. Although two dimensional analysis has been widely used for the assessment of weld residual stress, it has limitations to understand the stress distribution of the third direction. 3-D analysis was done to understand residual stress distribution of the welded plate. A simple butt-welded plate was considered to show the stress variation on all direction. A mock-up plate weldment was fabricated with SA-508 and F316L, which are widely used in nuclear power plants. The analysis results were validated with the measured values in the mock-up.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.86-91
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. the ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the ${\Delta}{\sigma}-N_f$ relation with the maximum stress at the edge of fillet welded joint.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.127-131
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds of structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. Thus, in this paper, ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the. ${\Delta}{\sigma}-N_f$ relation with the hot spot stresses at the gas welded joints.

• Journal of Plant Biology
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• v.5 no.3
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• pp.1-4
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• 1962

A district (Sae-Bong) and 13 district (Sae-Jang Dong) grassland could be divided into four type of Community: Miscanthus-Community, Glyceria-Community, Festuca-Community, and Plantago-Community. Chose 17 or 20 stands from each district A and B and calculated F.I. with the Curtis method, finally vegetational continuum could be recognized while discontinuous boundary line of species distribution could not be recognized. As a rule the distributional curve of species was binominal or bell shaped. It had a distribution pattern peculiar to itself. As to the relationship of cattles' density and vegetation. I found that the tendency of F.I. moving from small to large paralleled that of disturbance-pressure from weak to strong. Found that the more the steepness of environmental factors be controlled by a rule " from large to small", the more F.I. might be controlled by a rule "from small to large" and that pH, soil-moisture-content, loss on ignition was in relation with the steepness. with the steepness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.690-693
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• 2005

In this paper, probabilistic distribution of fatigue life of chassis component is determined statistically by applying the design of experiments and the Pearson system. To construct $p-\varepsilon-N$ curve, the case that fatigue data are random variables is attempted. Probabilistic density function(p.d.f) for fatigue life is obtained by design of experiment and using this p.d.f fatigue reliability about any aimed fatigue life can be calculated. Lower control arm and rear torsion bar of chassis component are selected as examples for analysis. Component load histories, which are obtained by multi-body dynamic simulation for Belsian load history, are used. Finite element analysis are performed using commercial software MSC Nastran and fatigue analysis are performed using FE Fatigue. When strain-life curve itself is random variable, probability density function of fatigue life has very little difference from log-normal distribution. And the case of fatigue data are random variables, probability density functions are approximated to Beta distribution. Each p.d.f is verified by Monte-Carlo simulation.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.2 s.191
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• pp.110-117
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• 2007

In this paper, probabilistic distribution of chassis component fatigue life is determined statistically by applying the design of experiments and the Pearson system. To construct p - ${\varepsilon}$ - N curve, the case that fatigue data are random variables is attempted. Probabilistic density function (p.d.f) for fatigue life is obtained by the design of experiment and using this p.d.f fatigue reliability, any aimed fatigue life can be calculated. Lower control arm and rear torsion bar of chassis components are selected as examples for analysis. Component load histories which are obtained by multi-body dynamic simulation for Belsian load history are used. Finite element analysis is performed by using commercial software MSC Nastran and fatigue analysis is performed by using FE Fatigue. When strain-life curve itself is random variable, the probability density function of fatigue life has very little difference from log-normal distribution. And the cases of fatigue data are random variables, probability density functions are approximated to Beta distribution. Each p.d.f is verified by Monte-Carlo simulation.

• Communications of the Korean Mathematical Society
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• v.17 no.3
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• pp.535-540
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• 2002

Let X$_1$, X$_2$‥‥,X$\_$n/ be n independent and identically distributed random variables with continuous cumulative distribution function F(x). Let us rearrange the X's in the increasing order X$\_$1:n/ $\leq$ X$\_$2:n/ $\leq$ ‥‥ $\leq$ X$\_$n:n/. We call X$\_$k:n/ the k-th order statistic. Then X$\_$n:n/ - X$\_$n-1:n/ and X$\_$n-1:n/ are independent if and only if f(x) = 1-e(equation omitted) with some c > 0. And X$\_$j/ is an upper record value of this sequence lf X$\_$j/ > max(X$_1$, X$_2$,¨¨ ,X$\_$j-1/). We define u(n) = min(j|j > u(n-1),X$\_$j/ > X$\_$u(n-1)/, n $\geq$ 2) with u(1) = 1. Then F(x) = 1 - e(equation omitted), x > 0 if and only if E[X$\_$u(n+3)/ - X$\_$u(n)/ | X$\_$u(m)/ = y] = 3c, or E[X$\_$u(n+4)/ - X$\_$u(n)/|X$\_$u(m)/ = y] = 4c, n m+1.