• 한국산림과학회지
• /
• 제59권1호
• /
• pp.57-62
• /
• 1983

Populus nigra${\times}$P. maximowiczii의 적정삽수(適正揷穗) 굵기를 구명(究明)하기 위하여 삽수직경별(揷穗直徑別) Clone별(別) 활착률(活着率)과 수고생장(樹高生長)을 연구(硏究)한 결과(結果)는 다음과 같다. 활착률(活着率) 80% 이상(以上)을 기준(基準)할 때 삽수(揷穗)굵기는 최소(最小) 8mm 이상(以上)이어야 하며 수고생장(樹高生長)과의 관계(關係)는 삽목(揷木) 후(後) 2개월(個月)까지는 삽수직경(揷穗直徑)이 클수록 수고(樹高)도 커지나 이러한 효과(効果)는 2개월(個月) 이후(以後) 즉(即) 7월(月)부터 점차 감소(減少)되는 경향(傾向)을 보였다. 삽수(揷樹)의 굵기가 13mm 이상(以上)되면 그 이하(以下)의 삽수(揷穗)보다도 현격(懸隔)히 활착률(活着率)(92.7%)이 높아지며 수고생장(樹高生長)도 좋아지는 경향(傾向)을 보였다. 일일수고생장(日日樹高生長)은 8월중(月中)에 최고점(最高點)에 달(達)했으며 이후(以後) 점차 감소(減少)하면서 10월(月) 상순(上旬)에는 거의 정지(停止)되는 것으로 추정(推定)된다.

• 한국연안방재학회지
• /
• 제6권3호
• /
• pp.111-120
• /
• 2019

In coastal morphological modelling, there are a number of input factors: wave height, water depth, sand particle size, bed friction coefficients, coastal structures and so forth. Measurements or estimates of these input data may include uncertainties due to errors by the measurement or hind-casting methods. Therefore, it is necessary to consider the uncertainty of each input data and the range of the uncertainty during the evaluation of numerical results. In this study, three uncertainty factors are considered with regard to the prediction of coastal erosion in Ilsan beach located in Ilsan-dong, Ulsan metropolitan city. Those are wave diffraction effect of XBeach model, wave input scenario and the specification of the coastal structure. For this purpose, the values of mean wave direction, significant wave height and the height of the submerged breakwater were adjusted respectively and the followed numerical results of morphological changes are analyzed. There were erosion dominant patterns as the wave direction is perpendicular to Ilsan beach, the higher significant wave height, and the lower height of the submerged breakwater. Furthermore, the rate of uncertainty impacts among mean wave direction, significant wave height and the height of the submerged breakwater are compared. In the study area, the uncertainty influence by the wave input scenario was the largest, followed by the height of the submerged breakwater and the mean wave direction.

• 한국초지조사료학회지
• /
• 제14권4호
• /
• pp.281-287
• /
• 1994

This experiment was canied out to determine the effects of 3cn1, 6cm, and lOcm of cutting height at harvest on the grass growth, dry matter(DM) yield, and weeds development in reed canarygrass(Phu1uris umndinacea L.) pasttire. The cultivars of reed canarygrass used in this study were Palaton. Veuture and Frontier(contro1). and the grass was harvested four times at soiling stage in 1992. The plant height at first harvest was 84, 96 and 94cm in Palaton, Venture and Frontier, respectively. The average regrowth height was same as 59cm in three cultivars. However, the regrowth height by cutting height was 61 -65cm in 6 and IOcm, and 51 -53cm in 3cm of low cutting height. Annual DM yield was not different in three cultivars of Palaton(l2.58lkg), Venture(l2,752kg), and Frontier (12,243kgIha). The yield at first harvmt wa5 significantly high in 3cm of height, however, the forage yields at second, third and fourth harvest were greatly high in 6cm of stubble height(P<0.05). Total yields by 3, 6 and lOcm of cutting height were 12.306. 14,094 and 11,342kg in Palaton, 12,794, 14,155 and 11,307kg in Venture, and 12,258, 12,940, and 11.535kglhg in Frontier, respectively. The highest yield was achieved in 6cm of stubble heigth(P<0.05). Daily DM production during grass regrowth was not affected by cultivars, and the best regrowth was observed by 6cm of cutting height. Development of weeds was high in 3cm of low stubble height, regradless of cultivars. The contents of crude protein, neutral detergent fiber, acid detergent fiber, and hemicellulose were not affected by cultivar and cutting height. In conclusion, it is suggested that the 6cm of cutting height is the most effective for grass regrowth, forage production, and weed control in reed canarygrass pasture. regradless of cultivm of Palaton, Venture and Frontier.

• 한국유기농업학회지
• /
• 제21권4호
• /
• pp.737-752
• /
• 2013

This study was conducted to evaluate the allelopathic effect of aqueous extract of Ganghwa domestic mugwort (Artemisia spp.) on vegetables and its related allelo-chemicals. When the receptor vegetables, such as Chinese cabbage, lettuce, and red radish, were treated with aqueous extract obtained from Sajabalssuk (A. $sp^*I$), Ssajuarissuk (A. $sp^*II$) or Ssajarissuk (A. $sp^*III$), their germination rate, leaf number, plant height, and root length were restricted with increasing concentration of aqueous extract. Allelopathic effect was the highest in radish, than lettuce and Chinese cabbage in order. The growth of topplant were more inhibited then root growth observing in restriction of plant height, root length, and chlorophyll contents. The plant height, the root length of red radish were 53.3 and 61.2% and their fresh weights were 19.8 and 26.4% compared to those of controls, respectively. A. $sp^*III$ showed the highest allelopathic effect among the donor plants. In HPLC analysis, 7 phenol compounds were identified in A. $sp^*I$ and A. $sp^*II$, and, in A. $sp^*III$, and hydroxybenzoic acid and phenylacetic acid were further identified as allelochemicals. It is considered that their plant growths were variously inhibited by the amounts and types of allelochemicals in aqueous extracts. To increase the productivity of farm land after cultivation of mugwort, these results can be useful to select the following field crops.

• 대한가정학회지
• /
• 제41권9호
• /
• pp.135-148
• /
• 2003

The purpose of this study was to examine the effect of clothing colors, clothing styles on women's body image perception. The experimental design was 2${\times}$2${\times}$9(perceiver's gender ${\times}$clothing styles${\times}$clothing colors) factorial design with between-subjects design. Subjects were 320 college students in the metropolitan area of Seoul. Perceiver's gender, clothing styles, and clothing colors gave a significant influence on the 3 variables of shoulder, the upper half of the body, and bust. Shoulder and the upper half of the body had an interaction effect by clothing styles and clothing color. Perceiver's gender gave a significant influence on hip size, length of leg, height, clothing styles did a significant influence on hip size, length of leg, height, and slender figure. Clothing colors gave a significant influence on length of leg, height, and slender figure. Length of leg and slender figure had an interaction effect by perceiver's gender and clothing styles. Hip size had an interaction effect by perceiver's gender and clothing color. Hip size had an interaction effect by clothing styles and clothing color. The results of this study support that coloration of clothing and clothing style affects perception of stimulus persons wearing apparel.

• Advances in concrete construction
• /
• 제10권5호
• /
• pp.455-462
• /
• 2020

This study investigated the effect of horizontal casting joints on the mechanical properties and structural behavior of sustainable self-compacting reinforced concrete beams (SCRCB). The experimental research consisted of two stages. The first stage used four types of concrete mixtures which were produced to indicate the effects of cement replaced with cement waste at 0%, 5%, 10%, and 15% by weight of cement content on fresh concrete properties of self-compacting concrete (SCC) such as, passing ability, filling ability, and segregation resistance. In addition, mechanical properties such as compressive, tensile, and flexural strength were also studied. The second stage selected the best mixture from the first stage and studied the effect of horizontal casting joints on the structural behavior of sustainable SCRCBs. The effect of horizontal casting joints on the mechanical properties and structural behavior were at the 25%, 50%, 75%, and 100% of sample height. Load deflection, failure mode, and theoretical analysis were studied. Results indicated that the incorporation of replacement with cement waste by 5% to 10% led to economic and environmental advantages, and the results were acceptable for fresh and mechanical properties. The results indicated that delaying the time for casting the second layer and increasing the cement waste in concrete mixtures had a great effect on the mechanical properties of SCC. The ultimate load capacity of horizontal casting joints reinforced concrete beams slightly decreased compared with the control beam. The maximum deflection of casting joint beams with 75% of samples height is similar with the control beam. The experimental results of reinforced concrete beams were substantially acceptable with the theoretical results. The failure modes obtained the best forced casting joint on the structural behavior at 50% height of casting in the beam.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제11권2호
• /
• pp.875-882
• /
• 2019

The effects of Triangle Groove Strips (TGS) on Vortex-induced Vibration (VIV) suppression of marine riser are numerically investigated using Computational Fluid Dynamics (CFD) method. The range of Reynolds number in simulations is 4.0 × 10⁴ < Re < 1.2 × 10⁵. The two-dimensional unsteady Reynolds-Averaged Navier-Stokes (RANS) equations and Shear Stress Transport (SST) k-ω turbulence model are used to calculate the flow around marine riser. The Newmark-β method is employed for evaluating the structure dynamics of marine riser. The effect of the height ratio (ε) of TGS on VIV suppression is evaluated. The amplitude responses, frequency responses, vortex patterns and the flow around the structures are discussed in detail. With the increase of the height ratio of TGS, the suppression effect of TGS on VIV suppression is improved firstly and then weakened. When ε=0.04, the suppression effect of TGS is the best. Compared with the VIV responses of smooth marine riser, the amplitude ratio is reduced by 38.9%, the peak of the lift coefficient is reduced by 69% and the peak of the drag coefficient is reduced by 40% when Re=6.0 × 10⁴. With the increase of Reynolds number, the suppression effect of TGS on VIV suppression is improved firstly and then weakened. When the Reynolds number is 7.0 × 10⁴, the amplitude ratio can be reduced by 40.1%. As to the large-amplitude vibration cases, the TGS show nice suppression effect on VIV.

• 설비공학논문집
• /
• 제21권12호
• /
• pp.703-714
• /
• 2009

One of the biggest problems in smoke control systems for high-rise buildings is stack effect, but there are no recognized methods or measures to solve the problem of stack effect as yet. The stack effect can be overcome by forming the uprising current inside the stair hall properly, but there is a limit to the height in supplying into the stair hall the smoke control air volume to be supplied to a floor in case of escape from fire. The limit to the height can be extended by over-coming the stack effect by pressurizing the stair hall and the ancillary room simultaneously. It can also be anticipated that the stack effect can be overcome by connecting the air supply shaft to the stair hall at the top. As a result of computer simulations using a network type of tool, it is found that adequate performance can be achieved by pressurizing the stair hall only for a building of 190m or less, and up to 360m when pressurizing the stair hall and the ancillary room simultaneously. In all those cases, however, an overpressure venting damper is required which operates within a suitable range for venting the overpressure outside.

• 대한디지털의료영상학회논문지
• /
• 제14권2호
• /
• pp.33-38
• /
• 2012

In EVAR procedure using long time C-arm, we studied exposure dose reduction and effeciency through measuring surgical staff's ESD by installing lead curtain operating table next to. The height 3 the spot (50cm, 100cm, 150cm) dose was measured on 2 locations for 600sec in the X-ray radiation considering the surgical staff's movement. To install the curtains, we compared before and after the dose. As a result, it can confirm that dose of the installation former of 50cm height and after is reduced about 75% and 91% in 2 locations. In 100cm height, the reduction of the dose was a bit confirmed. There as to dose value, measured on 150cm height the installation former and after was nearly no change. This research examined the exposure dose about the radiation of the surgical staff during EVAR procedure in which the operation time is the long time. It was implemented in the object that it reduces the radiation exposure. It could confirm the certain effect of the experimental result exposure dose reduction In EVAR procedure using long time C-arm, we studied exposure dose reduction and effeciency through measuring surgical staff's ESD by installing lead curtain operating table next to. The height 3 the spot (50cm, 100cm, 150cm) dose was measured on 2 locations for 600sec in the X-ray radiation considering the surgical staff's movement. To install the curtains, we compared before and after the dose. As a result, it can confirm that dose of the installation former of 50cm height and after is reduced about 75% and 91% in 2 locations. In 100cm height, the reduction of the dose was a bit confirmed. There as to dose value, measured on 150cm height the installation former and after was nearly no change. This research examined the exposure dose about the radiation of the surgical staff during EVAR procedure in which the operation time is the long time. It was implemented in the object that it reduces the radiation exposure. It could confirm the certain effect of the experimental result exposure dose reduction.

• 한국산림과학회지
• /
• 제97권1호
• /
• pp.95-101
• /
• 2008

중국 닝샤(寧夏)회족(回族)자치구 옌츠현(池縣) 샤췐완(沙泉灣)의 북경임업대학 사막화 방지연구기지 닝티아오 수림대(樹林帶)에서 실시한 방풍실험 결과는 다음과 같다. 1. 0.5m 높이의 각 열별(列別) 방풍효과(防風效果)를 분석한 결과, 1H(H = Tree Height) ~ 5H 까지의 방풍효과는 3열(30.22%) > 2열(26.53%) > 1열(16.28%)의 순으로, 7H 이후의 방풍효과는 2열(16.11%) > 3열(12.79%) > 1열(9.82%)의 순으로 나타났다. 2열과 3열의 회귀분석 결과, 2열 수림대의 방풍효과는 44H에 이르렀으며, 3열 수림대의 방풍효과는 27H에 이르렀다. 이 결과를 통해 단거리에는 3열 수림대의 방풍효과가 높고, 장거리는 2열 수림대의 방풍효과가 높다는 것을 알 수 있었다. 2. 1.0m 높이의 각 열별 방풍효과를 분석한 결과, 평균 방풍효과는 1열 8.04%, 2열 8.23%, 3열 7.43%로 큰 변화 없이 비교적 안정적인 풍속을 나타냈다. 3. 평균 방사효과(防砂效果)는 2열(55.28%) > 3열(37.13%) > 1열(20.87%)의 순으로 나타났으며, 특히 2열 수림대의 경우, 1H 지점에서 방사율이 86.06%로 가장 높은 방사효과를 나타냈다.