• Journal of Navigation and Port Research
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• v.36 no.5
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• pp.395-400
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• 2012

The stress-strain relationship of soil is dependent on a number of factors such as soil type, density, stress level and stress path. Th accurate stress-stain relationship can be predict using a constitutive model incorporated all influencing factors. In this study, an isotropic compression-expansion test and a series of drained conventional triaxial tests with several stress paths were performed on Baekma river sand to investigate parameters characteristics of Lade's single work hardening model depending on the stress path.. Based on test results, the parameters of yield function (h, ${\alpha}$) are not much influenced by stress level and stress path, the these parameters do affect a little bit of stress-strain behavior. The parameters h and ${\alpha}$ are closely related to failure criterion ${\eta}_1$, they can be replaced by failure criterion parament. We also observed that predicted values from the Lade's single hardening constitutive model are well matched with the observed data.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.803-811
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• 2014

This study was carried out to investigate the effect of relative humidity (70, 80, 90, and 95%) and to examine the interrelationship of temperature (15, 20, and $25^{\circ}C$) and relative humidity (60, 70, 80, and 90%) in the greenhouse on growth and occurrence of white rust in chrysanthemum 'Baekma'. The developmental stages of white rust were monitored from the initial occurrence to sporidium formation in teliospores. When the relative humidity of greenhouse was adjusted to 90% or more for 40 days, the occurrence rate of white rust, the number of infected leaves, and the number of symptoms per leaf were more than 97%, 10, and 55, respectively. However, in the treatment with 70% relative humidity, the occurrence rate of white rust dropped to 30% and only two spots of symptoms were observed with only 1 or 2 infected leaves per plant. The growth of cut flowers, such as fresh weight and leaf number, was the highest in 70% relative humidity. In the 90% relative humidity treatment, the first symptom of white spot appeared at 6 days after planting in chrysanthemum infected with white rust (stage 1), and then after one day, teliospores came out through the epidermal tissue of leaf (stage 2). The telium was formed with increasing teliospores after 1 to 2 days (stage 3), and then the promycelia developed from teliospores (stage 4). After a lapse of 4 to 5 days, sporidia formed on promycelia (stage 5). Regardless of relative humidity, white rust did not occur at all in treatments at $25^{\circ}C$. In treatments at $20^{\circ}C$, the number of sporidia was high regardless of relative humidity, but white rust did not occur in 60% and 70% relative humidity. As the relative humidity was higher, the number of sporidia and occurrence rate of white rust greatly increased, but the occurrence rate of white rust decreased to less than 14% in 60% and 70% relative humidity in treatment at $15^{\circ}C$.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.14-28
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• 2010

By philological geography method for dismantling and reconstituting Buyeo's Palkyung(扶餘 八景), which best signify the image of ancient city Buyeo's landscape, this research is to demonstrate the fact that the place's inertia of certain historic sites has been passed down as a type of geographic code. Titled poems and retrospective poems about Buyeo's Palkyung and its spectacles and landscapes reveal the fact that the splendid and glorious cultural heritage of Baekje had faded but its traces have remained in the each eight views including Nakhwa-am(落花巖), Goran-sa(皐蘭寺), and Jayong-dae(釣龍臺). In addtion, the spectacles and historic sites of Buyeo's Palkyung appear as the symbol of Baekje's fall and loss in the poems. Thus, it can be said that Buyeo's culture and civilization have never escaped from the cultural and historical scars of Baekhe's fall, being dominated by the place's inertia originated from the identity as "Baekje'slastcapital". It is ironical that Buyeo's future development and prosperity are not free from its cultural and historical spectacles which bear the image of the fall of Baekje. 'Older Buyeos' Palkyung(扶餘舊八景)' and, Prior Buyeo's Palkyung(夫餘前八景), originate from nine views of an unknown builder and after the construction of pavilions and towers, 'Subuk-jeong eight views(水北亭八景)' by Heungguk Kim(金興國) and the eight poems of the, Retrospect of Buyeo(扶餘懷古八景), were created. 'Buyeo's later Palkyung(扶餘後八景), which are especially free from the site's inertia are known to have expanded the scope of Buyeo's landscape by deliberately demonstrating spectacles and sites different from those of existing views. Nakhwa-am, Goran-sa, Joryong-dae, Songwal-dae(送月臺), Youngwal-dae(迎月臺), and Pyungje-tap(平濟塔) are all located within a one kilometer radius of Banwol-sung(半月城), Buyeo's palace and the Baekma river(白馬江), Daewang-po(大旺浦), Busan(浮山) in a two kilometers radius. Jaon-dae(自溫臺), Subuk-jeong(水北亭), and Gyuam-jin(窺岩津) are located within a three kilometers radius. Even Chunjeong-dae(天政臺), which are located within a four kilometers radius of Banwol-sung are located alongside the Baekma river. This indicates the fact that these spectacles had not been established temporarily or impromptu but for a long period time by historic retrospect and the inertia of landscape's geographic cycle. In conclusion, the geographic phenomenon of historical and cultural inertia appeared because Buyeo had the geographic message of "fallen, ancient city". Therefore, Buyeo's Palkyung which have constant retrospective inertia is clearly an geographic code effective and helpful to understand not only the characteristics of historic sites and spectacles of Buyeo in the Sabi period but also the quality of the site itself.

• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.251-255
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• 2009

This study was conducted to investigate effect of ionic strength and feeding times of a nutrient solution on reduction of stem cavity size and improvement of flower quality in chrysanthemum 'Baekma'. A nutrient solution was applied with different strengths at three stages, namely, transplanting, budding, and flowering. The solution EC was adjusted as 1.61.82.0, 1.81.81.8, 1.82.01.8, and $2.02.02.0dS{\cdot}m^{-1}$ in four treatments. Feeding frequency per a day were 4 times for 12 min., 8 times for 6 min., 12 times for 4 min., and 18 times for 2.7 min. each. Cut flower length as affected by different strengths of a nutrient solution was the greatest in the plot of EC $2.02.02.0dS{\cdot}m^{-1}$. However number of leaves, stem diameter, and leaf size were greater in EC $1.82.01.8dS{\cdot}m^{-1}$ than in other treatments. Also, petal number of petals was the greatest and stem cavity size was the smallest in the plot of EC $1.81.81.8dS{\cdot}m^{-1}$. Plant height, number of leaves, stem diameter, leaf size were greater in the plot with 12 times feed ing per a day. number of petal was most in the plot with 8 times feeding per day, while stem cavity size was the smallest in the plot with 12 times feed ing per a day. Therefore, the better plant growth, the smaller stem cavity size.

• Clean Technology
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• v.10 no.1
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• pp.47-51
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• 2004

현재 반도체 공정에서 사용되는 세정기술은 대부분이 1970년대 개발된 RCA 세정법인 과산화수소를 근간으로 하는 습식 세정으로, 표면의 입자를 제거하기 위한 SC-1 세정액은 강력한 산화제인 과산화수소에 의한 표면과 입자의 산화와 암모니아에 의한 표면의 에칭이 동시에 일어나 입자를 표면으로부터 분리시킨다. 금속 불순물을 제거하기 위한 SC-2 세정액은 염산과 과산화수소 혼합액을 사용하며 금속 불순물을 용해시켜 알칼리나 금속 이온을 형성하거나 용해 가능한 화합물을 형성시켜 제거한다. 또한 황산과 과산화수소를 혼합한 Piranha 세정액은 효과적인 유기물 제거제로서 웨이퍼에 오염된 유기물을 용해 가능한 화합물로 만들거나 과산화수소에 의해 형성되는 산화막내에 오염물을 포함시켜 불산 용액으로 산화막을 제거할 때 함께 제거된다. 최근 금속과 산화막을 동시에 제거하기 위해 희석시킨 불산에 과산화수소를 첨가한 세정공정이 사용되고 있으며 불산에 의해 표면의 산화막이 제거될 때 산화막내에 포함된 금속 불순물을 동시에 제거시킬 수 있다. 그러나 이와 같이 습식세정액 내에 공통적으로 포함되어 있는 과산화수소의 분해는 그만큼 가속화되어 사용되는 화학 약품의 양이 그만큼 증가하게 되고 조작하기 어려운 단점도 있다. 이를 해결하기 위해 환경친화적인 관점으로 화학약품의 사용을 최소화하는 등 RCA세정을 보완하는 연구가 계속 진행되고 있다. 본 연구에서는 RCA세정법을 환경적으로 대체할 수 있는 세정에 사용되는 전리수의 pH변화에 따른 전리수 분석을 하였다. 전리수의 제조를 위하여 전해질로는 NH4CI (HCI:H2O:NH4OH=1:1:1)를 사용하였다. pH 11 이상, ORP -700mV~-850mV인 환원수와 pH 3 이하, ORP 1000mV~1200mV인 산화수를 제조하였으며, 초순수를 첨가하여 pH 7.2와 ORP 351.1mV상태까지 조절하였다. 이렇게 만들어진 산화수와 환원수를 시간 변화와 pH 변화에 따라 Clean Room 안에서 FT-IR과 접촉각 측정기로 실험하였다. FT-IR분석에서 산화수는 pH가 높아질수록, 환원수는 낮아질수록 흡수율이 낮아졌다. 접촉각 실험에서는 산화수의 pH가 높아질수록 환원수의 pH가 낮아질수록 접촉각이 커짐을 확인하였다. 결론적으로 전리수를 이용하여 세정을 하면, 접촉성을 조절할 수 있어 반도체 세정을 가능하게 할 수 있으며, 환경친화적인 결과를 도출할 것으로 전망된다.

• Journal of the Korean Geosynthetics Society
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• v.11 no.2
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• pp.1-9
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• 2012

In order to review the utility of Lade's single hardening constitutive model, a series of isotropic compression-expansion tests and consolidated drained triaxial tests including as CTC, TC, RTC, and OSP were performed by Baekma river sand with various of stress path. Parameters required in model were determined using these tests. The accuracy of analysis was reviewed by back analysis of test results used to determine the 11 parameters of soil property through the test of each stress path. Also. for verifying the accuracy of prediction for the stress-strain behavior using failure criterion related 9 parameters with correlational equation and constant and yield criterion related parameters h, ${\alpha}$ and ${\eta}_1$, when stress path is different with each other, it has been obtained in the review result of stress path dependent characteristics of the constitutional model through the analyzing results of CTC, TC, RTC, OSP, and fine silica sand tests.

• Communications of Mathematical Education
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• v.23 no.1
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• pp.1-38
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• 2009

This study investigates the relationships of perfectionism and the affective traits(academic self-concept, learning attitude, interest, mathematical anxiety, learning habits) in mathematics between the gifted students and the regular students in Korean Middle Schools. The findings of this study can be used for the understanding of the gifted students, and as data or resources for counsellors when they advise the gifted students on enhancing study strategies and developing future courses. This study was investigated by measuring the relationships between perfectionism and the affective traits on mathematics between two groups. Here, the correlation analysis, t-test, and regression analysis of the SPSS for Window 12.0 Program were applied to measure the differences of both groups. Therefore, there were no differences in perfectionism between the gifted students and the regular students. But the self-oriented perfectionism of the gifted students appeared higher compare with regular students. The affective traits in mathematics of the gifted students appeared more positive compare with regular students. There were a few correlations between the perfectionism and the affective traits in mathematics at two group all. however the self-oriented perfectionism and the affective traits in mathematics showed to correlation. There were several suggestions based on the results of this study. First, the results showed that professional assistance is needed for the gifted students so that their perfectionism flows positively into developing their gifts. Secondly, the results suggested that specialized mathematical program reflecting on the affective traits of the gifted students in mathematics should be offered.Lastly, tthe results of this study suggested a researcher regarding relevance with perfectionism and affective traits regarding subject shall be performed more. The result of research shall be included to contents of training for the gifted students and their parents.