• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.94-94
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• 2021

현재 전 지구적으로 일어나고 있는 극단적 기후현상과 이로 인한 자연재해의 원인은 복합적이다. 기후변화로 인한 영향과 동시에 도시화 또한 하나의 원인으로 작용하고 있다. 이러한 영향을 완화하기 위한 방안으로 도시의 그린인프라와 저영향개발은 최근 지속가능한 발전을 위해 꼭 필요한 요소로 자리잡고 있다. 그린인프라 유형 중 하나인 옥상녹화는 많은 이점을 제공한다. 도시에 위치한 건물의 상층부, 내부 및 주변 온도을 낮춤으로써 얻을 수 있는 에너지절감 효과와 강우 시 상당량의 빗물을 저류함으로써 기대되는 우수유출 저감효과, 그리고 도시 공간 내 식물의 적극적인 도입으로 인한 이산화탄소 배출 저감 효과 등을 기대할 수 있다. 본 연구에서는 도시지역의 열섬현상완화와 유출저감의 방안 중 하나인 옥상녹화(Green roof)의 효과를 정량적으로 평가하기 위해 콘크리트로 이루어진 동일한 제원의 실험동을 구축하고, 실험동 내외부의 연직방향 온도, 습도, 강우, 풍속, 일사량 등의 기상자료를 측정할 수 있는 센서를 설치하였다. 각 실험동에서 측정된 기상자료를 Flux Profile Method를 적용하여 무강우기간과 강우발생기간 동안의 연직 방향의 현열속, 잠열속, 토양열속(H, LE, G) 을 산정하였다. 에너지 평형에 따라 산정된 각 실험동의 열속과 지표면 복사량 관측자료을 정량적으로 비교하여 적용성을 평가하였다. 실험의 대조군인 일반 코팅재로 마감된 콘크리트 지붕의 무강우 기간 중 최대 현열속 693.82 W/m² 잠열속은 330.15 W/m² 으로 나타났으며, 실험군인 옥상녹화가 조성된 지붕의 최대 현열속 436.27 W/m², 잠열속 949.20 W/m² 으로 나타났으며, 산정치와 관측치 시계열의 NSE는 0.81 으로 Flux Profile Method를 통해 산정된 열속의 정확도는 비교적 높은 것으로 나타났다. 이와 같은 방법으로 옥상녹화의 정량적 평가가 가능해짐으로써 향후 기후변화 대응방안 및 전략 수립 시 옥상녹화의 온도저감효과 분석에 적극 활용할 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.414-414
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• 2020

고전 천수방정식을 적용한 2차원 도시홍수 모델링에서는 지형의 정확한 반영을 위해 고해상도 격자가 요구되며 이는 많은 계산시간과 노력을 필요로 한다. 최근에는 다공성 천수방정식을 적용한 도시홍수해석으로 많은 계산 노력이 요구되는 도시홍수모델링의 한계를 극복한 연구가 많이 이루어지지고 있다. 이러한 연구는 도시 홍수에서 흐름이 공간적으로 변화할 때 불균일 공극이 존재하므로 격자의 크기를 다르게 하여 이러한 불균일성을 해결하고자 하는 등방성 천수모형의 적용에서 시작되었다. 하지만, 등방성 공극을 고려한 도시홍수 해석모형은 대표요소체적(REV)보다 더 큰 격자의 적용을 해야 하는 제한성을 가진다. 반면, 비등방성 공극은 대표요소체적의 적용이 필요하지 않아 불균일 공극의 크기에 관계없이 이론상으로는 동일한 해상도의 격자가 사용가능하긴 하지만, 실제 도시홍수 해석에서 중요하면서도 도전적인 연구이다. 본 연구에서는 도시홍수의 효율적 계산을 위해 비등방성 공극을 고려한 적분형 다공성 천수방정식을 기반으로 하는 2차원 도시홍수 해석모형을 개발하였다. 모형의 개발을 위해, 적용 격자내에서 도시지역의 건물이 차지하는 길이 및 면적을 산정하고 그 값을 2차원 천수방정식에 적용 가능하도록 체적공극(𝜙_j)와 면적공극(𝜓_k)을 2차원 고전 천수방정식에 추가하였다. 개발모형은 고전 천수방정식, 등방성 공극 고려(미분형 다공성) 천수방정식 및 비등방성 공극 고려(적분형 다공성) 천수방정식의 적용이 가능하여, 각 모형에 적합한 2차원 격자 생성, 각 모형의 매개변수를 보정 그리고 정확성, 효율성, 적용성이 비교 가능하다. 각 모형의 정확성과 효율성 비교를 위해 3가지의 오차 비교 (구조적 오차, 격자크기 오차, 공극 모형 오차), 계산시간 비교, 공간 변동성 검증을 위한 수심 종단형상 비교하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.37-44
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• 2010

The present annexed parking lot standards for buildings in Parking Act are categorized in 9 groups with 13 parking standards in terms of recreation, culture and assembly, housing, factory, warehouse, and so on, in which same grouped facilities have same parking standards. These days diversity in building types and functions need more fractionated parking standards; however, most local governments focusing merely on applying strengthened parking standards in general without systematic rules of consistency. The current problem of parking standards being used is lack of regarding facility characteristics; expecially, a large sized high-tech manufacturing facility located in industrial site is still applied by same parking standards as normal manufacturing facility, even though most part of manufacturing process is automated and hence less manpower is employed. This paper presents a parking generation forecasting model for factory facilities in industrial site in terms of facility use and scale characteristics.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.145-154
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• 2007

As buildings are built higher and their service life made longer, face brick walls are also required to be constructed in an easy and systematic manner, and to ensure their satisfying structural performance, inspectingly, against lateral load. Therefore this study aims to investigate the structural performance of face brick walls constructed by a new method using screwed stainless steel connectors and provide fundamental experiment data for field application of this method. The results of this study indicated that the face brick wall tied with screw connectors had better shear capacity against rocking motion than that of the wall constructed with ordinary tie bars when their tie spacing was the same. Based on the good performance of the wall tied with the screw connector, it is also expected that the spiral anchors developed in this study can possibly applied to high-rise by adjusting the spacing of the anchors considering the difference of dimensions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.246-261
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• 2023

We investigated critical temperature for early marginal transplanting (CT-EMT) of the contemporary japonica rice varieties in Korea through the field, pot seedling tray, and the phytotron experiments during 2020 to 2023. The lowest mean temperature for 10 days from transplanting (MT-10DFT) that resulted in earlier heading date was 12.4℃ and the highest MT-10DFT that did not show the earlier heading date was 12.0℃ in the field study when the MT-10DFT varied by changing transplanting date. The lowest MT-10DFT that induced the increased biomass but not the earlier heading date was 11.6℃ and the highest MT-10DFT that showed neither the increased biomass nor the earlier heading date was 11.4℃. Compared to the 10-day later transplanting, the dates of the first root development, initiation of the chlorophyll recovery, and the first tiller development were earlier when the MT-10DFT was 9.1℃ or higher, 10.5℃ or higher, and 11.6℃ or higher, respectively, in the pot seedling tray and field experiments. The earliness of the first tiller development was a practical index for the estimation of CT-EMT during the early growth stage of rice. The response of transplanted rice to temperature treatments with the diurnal change of 10℃ in the phytotron study was similar to that shown in the field study. The data shown for constant temperature without a diurnal change revealed that the extent of positive effects of high temperature at day-time was greater than the extent of negative effects of low temperature at night-time on the early growth of transplanted rice. It was concluded that the critical MT-10DFT for early marginal transplanting of japonica rice in the temperate environments was between 11.4 to 11.6℃ based on the plant growth and between 12.0 to 12.4℃ based on the plant development.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.39-46
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• 2015

Objective of this research was to investigate the influence of compositions and concentrations of fertilizer solutions on the vegetative growth and nutrient uptake of 'Seolhyang' strawberry. To achieve this, the solutions of acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) were prepared at concentrations of 100 or $200mg{\cdot}L^{-1}$ based on N and applied during the 100 days after transplanting. The changes in chemical properties of the soil solution were analysed every two weeks, and crop growth measurements as well as tissue analyses for mineral contents were conducted 100 days after fertilization. The growth was the highest in the treatments with BF, followed by those with NF and AF. The heaviest fresh and dry weights among treatments were 151.3 and 37.8 g, respectively, with BF $200mg{\cdot}L^{-1}$. In terms of tissue nutrient contents, the highest N, P and Na contents, of 3.08, 0.54, and 0.10%, respectively, were observed in the treatment with NF $200mg{\cdot}L^{-1}$. The highest K content was 2.83%, in the treatment with AF $200mg{\cdot}L^{-1}$, while the highest Ca and Mg were 0.98 and 0.42%, respectively, in BF $100mg{\cdot}L^{-1}$. The AF treatments had higher tissue Fe, Mn, Zn, and Cu contents compared to those of NF or BF when fertilizer concentrations were controlled to equal. During the 100 days after fertilization, the highest and lowest pH in soil solution of root media among all treatments tested were 6.67 in BF $100mg{\cdot}L^{-1}$ and 4.69 in AF $200mg{\cdot}L^{-1}$, respectively. The highest and lowest ECs were $5.132dS{\cdot}m^{-1}$ in BF $200mg{\cdot}L^{-1}$ and $1.448dS{\cdot}m^{-1}$ in BF $100mg{\cdot}L^{-1}$, respectively. For the concentrations of macronutrients in the soil solution of root media, the AF $200mg{\cdot}L^{-1}$ treatment gave the highest $NH_4$ concentrations followed by NF $200mg{\cdot}L^{-1}$ and AF $100mg{\cdot}L^{-1}$. The K concentrations in all treatments rose gradually after day 42 in all treatments. When fertilizer concentrations were controlled to equal, the highest Ca and Mg concentrations were observed in AF followed by NF and BF until day 84 in fertilization. The BF treatments produced the highest $NO_3$ concentrations, followed by NF and AF. The trends in the change of $PO_4$ concentration were similar in all treatments. The $SO_4$ concentrations were higher in treatments with AF than those with NF or BF until day 70 in fertilization. These results indicate that compositions of fertilizer solution should to be modified to contain more alkali nutrients when 'Seolhyang' strawberry is cultivated through inert media and nutri-culture systems.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.355-372
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• 2004

In vitro experiments were conducted to determine the formation of fatty acid soaps (FAS) and neutral detergent fiber (NDF) disappearance rate. The substrates were a basal alfalfa hay containing 1) no oil, 2) 10% soybean oil, 3) 10% com oil, on a weight basis. All the substrates were incubated in triplicate for 0, 3, 6, 12, 24 and 48h in each experiment. After the incubation in the first experiment serum bottles (6oml) were analyzed for nonesterified, esterifed and fatty acid soaps contents. The serum bottles (120mI) from the second experiment were analyzed for pH, $NH_3-N$ and VFA concentration, and dry matter and NDF disappearance rate. pH decreased and the concentration of NH3-N increased significantly with longer incubation time (P<0.0001). The disappearance rates of dry matter and NDF significantly varied with feed, incubation time and oils (P<0.05). The molar concentration of total VFA increased and proportion of acetate significantly decreased with incubation time (P<0.0001), but the proportion of propionate significantly increased with longer incubation time (P<0.0001). Addition of oils to diet lowered the ratio of acetate:propionate (P<0.05). The esterified fatty acids (EFA) decreased with increasing incubation time (P<0.0001), and nonesterified fatty acids (NEFA) increased due to lipolysis of EFA, NEFA then reacted with cations to increase formation of FAS. The formation of FAS increased significantly at 48h of incubation time (P<0.0001). Especially, formation of stearic acid soaps was 27.5 and 32.5 folds with soybean oil and com oil supplements, respectively, by 48h of incubation time (P<0.0001). Alfalfa hay had higher cation contents, particularly Ca, which react with NEFA and FAS can be formed with longer incubation time. Saturated fatty acids had a higher proportion of FAS than did unsaturated fatty acids, suggesting that the former may react more extensively with cations. FAS contents increased with increasing chain length of the fatty acids. Since added vegetable oils fonned FAS, it might decrease negative effects on in vitro fermentation characteristics and NDF disappearance rate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.161-169
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• 2005

With various Korean domestic soybeans, growth and yields analysis were conducted to select the suitable soybean cultivars for cultivation in paddy field. Distinctive aspects of the soybean growth were observed in paddy field such as retarded growth of top plants and roots, relatively higher T/R ratio followed by overgrowth of top plant. However, growth and yields were significantly different among the cultivars showing 134kg/10a in Paldokong and 385 kg/10a in Doremikong. At V5. and R2 stage, highly positive correlations $(r=0.76^{**}\~0.91^{**})$ were observed between leaf area and dry weight of top plant and/or root. T/R ratio was negatively correlated with dry weight of root $(r=-0.37^*)$ at V5 stage, while significantly correlated with leaf area $(r=-0.37^{**})$ and dry weight of top plant $(r=0.65^{**})$at R2 stage. Among the characters, only 100-seed weight was significantly correlated with yield. Considering the growth characters, 37 cultivars could be included in 3 different groups and genotypic properties such as maturity and growth habit were similar in each group. Nine cultivars in group 1 showed retarded growth from V5 to R2 stage, relatively lower T/R ratio, and good seed ripening. Average yields of the cultivers was 257kg/10a. In group 2, 12 cultivars showed higher T/R ratio due to overgrowth of top plant and lowest average yields (230 kg/l0a) due to poor seed ripening. Sixteen cultivars in group 3 grew fast from V5 to R2 stage representing late maturity traits, low T/R ratio, and good seed ripening. Average yields of the cultivars was highest among groups showing 270kg/l0a. In results, stable self-sufficiency of soybean yields could be expected by selective cultivation with high yielding cultivars ranging from 301 to 385kg/10a, such as Shinpaldalkong 2, Sohokong, Doremikong, Keumkangkong, Bukangkong, Dajangkong, and Geomjeongkong 2, or with cultivars included in group 3.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.4
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• pp.317-324
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• 2010

Recently, fallow paddy land located in the mid-mountain area (FPL) due to a decrease in rice consumption has increased in some regions of our country. So, grasses and forage crops available for years in once sowing should be introduced in FPL. This study was conducted to develop the technique for cultivation of grasses and forage crops using animal manure in FPL The field experiments were carried out from 2007 to 2009 on FPL at Kumsan, Chungbuk province in Korea. Cattle feedlot manure (CFM) was prepared by mixing feces and urine of cattle with rice straw in cattle feedlot for 6 months. The experimental plots were consisted of four treatments; tall fescue-based mixed pasture applied with chemical fertilizer (Control), mono-tall fescue pasture (MTFP), tall fescue-based mixed pasture (TFBMP), mono-Perennial ryegrass (MPR-FCM), mono-Italian ryegrass (MIR-FCM), mono-Red clover (MRC-FCM) and mono-Reed canarygrass (MRCG-FCM) applied with FCM. The field of tall fescue-based pasture had been sown with a grasses mixture containing 'Fawn' tall fescue, 'potomac' orchardgrass, 'Reveille' Perennial ryegrass, and 'kenblue' Kentuky bluegrass, 'Kenland' Red clover. Seeding rates were 16, 6, 4, 2 and $2\;ha^{-1}$, respectively. DM yields of forages and rates of grass coverage was higher in MTFP, TFBMP and MRCG-FCM as compated with control treatment. This result means that FPL has contained with favorable conditions for growing grass, because forage productivity is more than 15 tons per ha per year in fallow paddy land. In addition, the farmer can save the trouble of repeated plowing and sowing every year, due to the introduction of perennial grasses. The farmer must conduct the re-seeding and induce the improvement of management methods for the elevation of the persistence of red clover and perennial ryegrass, because both red clover and perennial ryegrass having high nutritive value and palatability was less persistent. Therefore, we suggest that FPL may be the good land for forage production utilizing FCM and FCM can be applied on FPL without any negative effects on DM production and the property of soil. FPL of Korea can be better utilized by applying FCM to the mono and/or mixed swards.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.115-122
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• 2002

In this study, the effects of alfalfa hay included in different ratios of 60%(A), 50%(B), 40%(C) and 30%(D) for the diets of young weaned Korean native goats were investigated on feed intake, digestibilities of nutrients, nitrogen retention, average daily gain and feed efficiency. Crude protein contents of experimental diets were 18% in all treatments. The contents of ADF, NDF and crude ash were higher in A as 26.1, 37.0 and 9.0% compared to the lowest values in D of 20.3, 30.4 and 6.6%. However the contents of non-structural carbohydrates was in the opposite tendency. Daily feed intake (DM) was highest in A (414.4g) and B (417.7g) and significantly (p<0.05) lower in D(362.6g). Dry matter intake per metabolic basal weight (DM g/kg of $BW^{0.75}$ ) were highest in A(73.9g) and lowest in D(64.0g). Average daily gain and feed efficiencies were in the range of 33.3~48.7g and 8.1~13.4% respectively with no statistical differences, however with the increasing trends according to higher percent of roughage in the diets. Digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ADF, NBF, crude ash (CA) and non-structural carbohydrates (NSC) were in the tendency of becoming higher according to higher ratios of concentrate but becoming lower according to higher ratio of alfalfa hay in the diets fed to Korean native goats. Nitrogen retention was lowest in A (1.8g, 15.5%) and highest in D (2.7g, 25.7%). In overall, inclusion of 30~40% alfalfa hay as a roughage in the diets of weaned Korean native goats was superior to the higher rates of inclusion of alfalfa hay in aspects of average daily gain and feed efficiency. The fixed 18% of crude protein content in the diets was efficient for the growth of weaned goats.