• 한국수학교육학회지시리즈B:순수및응용수학
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• 제18권4호
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• pp.361-368
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• 2011

In this paper, we construct a cover ($\mathcal{L}(X)$, $c_X$) of a space X such that for any cloz-cover (Y, f) of X, there is a covering map g : $Y{\longrightarrow}\mathcal{L}(X)$ with $c_X{\circ}g=f$. Using this, we show that every Tychonoff space X has a minimal cloz-cover ($E_{cc}(X)$, $z_X$) and that for a strongly zero-dimensional space X, ${\beta}E_{cc}(X)=E_{cc}({\beta}X)$ if and only if $E_{cc}(X)$ is $z^{\sharp}$-embedded in $E_{cc}({\beta}X)$.

• 한국유기농업학회지
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• 제20권2호
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• pp.173-183
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• 2012

유기과원에서 자생하는 겨울나기 한해살이 초종을 조사하여 과수에 양분공급을 할 수 있는 유망한 녹비자원을 선정하기 위해서 2009년에 수행되었다. 전남지역에 위치한 유기과원 총 13곳을 선정하여 4월과 6월에 자생하는 초종을 조사하였다. 건물중은 4월에 쥐보리가 6월에는 참새귀리가 가장 높았다. 초종별 질소와 칼리의 토양 환원량은 4월에는 쥐보리와 새완두 살갈퀴가 높았고 6월에는 참새귀리가 가장 높게 나타났다. 본 시험에서는 두과 작물인 새완두와 살갈퀴가 토양에 충분한 양의 양분을 환원할 수 있는 유망한 녹비자원으로 판단되었다. 인산은 초종에 상관없이 10~15년생의 과일나무가 생장하기 위해 필요한 수준 이하를 나타내어 추가의 외부 공급이 필요하였다.

• 한국환경과학회지
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• 제27권5호
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• pp.291-297
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• 2018

Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring $30{\times}17{\times}17cm$, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1018-1031
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• 2010

In order to investigate the applicability and suitability of the industrial by-products to landfill final cover, field pilot-scale lysimeter experiments were carried out. The mixture of loamy soil, bottom ash, and construction waste was placed as a cover material in lysimeter($2m{\times}6m{\times}1.2m$) which were constructed with cement brick, and then, volumetric water contents, pF value, and the quantity of runoff and seepage of treatment boxes filled with the mixture of loamy soil and the industrial by-products were monitored from July, 2007 to February, 2008. Among the cases tested, consequently, the case containing the mixture of bottom ash and loamy soil was most effective in engineering and hydrological properties and water retention ability.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제20권2호
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• pp.103-108
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• 2013

Observing that for any space X, there is a Wallman sublattice $\mathfrak{A}_X$ and that QFX is homeomorphic to a subspace $X_q$ of the Wallman cover $\mathfrak{L}(\mathfrak{A}_X)$ of $\mathfrak{A}_X$, we show that ${\beta}QFX$ and $\mathfrak{L}(\mathfrak{A}_X)$ are homeomorphic.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1655-1665
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• 2008

In order to investigate the applicability and suitability of the industrial by-products to landfill final cover, field pilot-scale lysimeter experiments were carried out. The mixture of loamy soil, bottom ash, and construction waste was placed as a cover material in lysimeter($2m{\times}6m{\times}1.2m$) which were constructed with cement brick, and then, volumetric water contents, pF value, and the quantity of runoff and seepage of treatment boxes filled with the mixture of loamy soil and the industrial by-products were monitored from July, 2007 to February, 2008. As a result, the case containing the mixture of bottom ash and loamy soil was most effective in engineering and hydrological properties and water retention ability.

• 대한수학회보
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• 제30권1호
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• pp.117-124
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• 1993

In this paper, we introduce a concept of quasi $O_{z}$ -spaces which generalizes that of $O_{z}$ -spaces. Indeed, a completely regular space X is a quasi $O_{z}$ -space if for any regular closed set A in X, there is a zero-set Z in X with A = c $l_{x}$ (in $t_{x}$ (Z)). We then show that X is a quasi $O_{z}$ -space iff every open subset of X is $Z^{#}$-embedded and that X is a quasi $O_{z}$ -spaces are left fitting with respect to covering maps. Observing that a quasi $O_{z}$ -space is an extremally disconnected iff it is a cloz-space, the minimal extremally disconnected cover, basically disconnected cover, quasi F-cover, and cloz-cover of a quasi $O_{z}$ -space X are all equivalent. Finally it is shown that a compactification Y of a quasi $O_{z}$ -space X is again a quasi $O_{z}$ -space iff X is $Z^{#}$-embedded in Y. For the terminology, we refer to [6].[6].

• 한국지반공학회논문집
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• 제26권7호
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• pp.81-91
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• 2010

기존의 최종복토시스템에 대한 문제를 해결하기 위한 단층형 복토시스템의 복토재로서 석탄회(저회)의 활용성을 검토하기 위해서 현장대형토조시험을 수행하였다. 산업부산물의 관련 활용규정에 준하여 석탄회를 일반토사와 혼합하여 현장에서 설치한 대형토조에 채워 넣어 관측기간동안(2007년 7월~2008년 2월) 단층형 복토시스템의 복토재로 서 그 활용성를 일반토사만을 채운 처리구 그리고 일반토사에 건설폐기물을 혼합한 처리구와 함께 비교하였다. 그 결과 일반토사에 석탄회를 적용시킨 처리구가 매립지의 복토재로서 우선시 되는 수분저류능력과 식물의 생육면에서 가장 좋은 결과가 나타났다.

• 아시안잔디학회지
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• 제7권1호
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• pp.19-30
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• 1993

Experiments were conducted to investigate propagation, shade tolerance, cold resistance and growth rate of evergreen ground cover plants ; Vinca minor K , Ajuga reptans L., Ophiopogon japonicus ker. f nanus hort , and Hedera helix.. The results were as follows : 1.It is convenient to use the growing case for rice seed to grow and transplant Vinca minor seed-ling. The most proper density of transplanting Vinea was 180 plants per 1m$^2$. At the end of growing season, the coverage came up to 90% The rooting ability of Hedera helix was best to cut from April to May (temperature 15~23˚C). The seedling length of Parthenocissus quinguefohlia were irregular and ranged from 5 cm of 200cm. 2. Ajuga reptans L., Ophiopogon j. and Vinca minor L. grew better under 50% light intensity than full sunlight. Particularly, under full sunlight and aestival high temperature, there were a few withering plants in Ajuga reptans L. , and V Vilica minor L. 3. Of Vinca minor K., Ajuga reptans L. , Ophiopogon japonicus ker. f. nanus hort. and Hedera helix. acclimatized in open field, where temperature was from -7~8˚C. There were few plants had damage in low temperature incubator to -16˚C after field acclimatization. 4.Tendrils of Parthenocissus quinguefolia strongly clung to the wire netting stone fence but intruded into the gap and cranny of the precast concrete fence and so clung to, so that it needed to install the bending net on the precast concrete fence.

• 농업과학연구
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• 제12권1호
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• pp.108-117
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• 1985

파종기(播種機)의 복토장치(覆土裝置) open auger의 토양이송과정(土壤移送過程)을 이론적(理論的)으로 분석(分析)하여 이송효율(移送效率)을 산출(算出)할 수 있는 이론적(理論的)인 동력효율식(動力效率式)을 유도(誘導)하고, open auger의 회전속도(回轉速度)의 적정범위(適定範圍), 그러고 auger 내(內)에서 토양(土壤)의 축방향(軸方向) 토립자(土粒子) 이송속도(移送速度)를 구명(究明)하였다. Open auger의 특성(特性)의 이론적(理論的)인 분석(分析)과 분석응용(分析應用)의 결과(結果)는 다음과 같다. 1. 동력효율(動力效率)의 예측식(豫測式)은 다음과 같다. ${\eta}_p={\frac{P_n}{P_g}}=({\frac{{\omega}_s}{{\omega}_a}}){\cdot}tan{\gamma}{\cdot}{\frac{mg}{F_mcos{\alpha}+F_scos{\gamma}}}$ 2. 보다 적은 동력(動力)으로 소정(所定)의 폭(幅)까지 토양이송(土壤移送)이 원활(圓滑)히 이루어질 수 있는 open auger의 회전속도(回轉速度)의 적정범위(適定範圍)는 다음과 같다. $$\frac{4d(L_a-L_i){\cdot}V_w}{{\pi}(D_o^2-D_s^2)r{\cdot}{\frac{{\omega}_s}{{\omega}_a}}{\cdot}tan{\gamma}}{{\leq_-}}{\omega}_a{{\leq_-}}({\frac{{\omega}_a}{{\omega}_s}}){\sqrt{\frac{g}{r}}}$$ 3. Auger 내(內)에서 토양(土壤)의 축방향(軸方向) 이송속도(移送速度)는 다음식(式)으로 구할 수 있다. $V_h=({\frac{{\omega}_s}{{\omega}_s}})V_a{\cdot}tan{\gamma}$ 4. Auger의 회전속도(回轉速度)는 다른 여러 인자(因子)들보다 동력효율(動力效率)에 가장 크게 영향(影響)을 미치는 것으로 나타났다.