• Journal of Conservation Science
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• v.17 s.17
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• pp.73-82
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• 2005

The Bunhwangsaseoktop is the oldest stone brick pagoda in Silla Period. The pagoda body is made by piling small brick-shaped stones trimmed from black andesite and the first-story core has a shrine, which is made by granite. In 1915 it was repaired on a large scale, but now is severely damaged. Many kind of the stone decay like flaking, granular disintegration have occurred especially on the granite surface of the pagoda. In this study have been investigated the stone decay type and its cause in relation to efflorescence on the body part. Various analysis show that the deterioration on the granite is due to the same materials that lead to efflorescence on the body stone surface. The soluble salt like sodium nitrate, calcium sulfate and sodium sulfate come from white joint mortar. This salt solution is recrystallized in the outside of the pagoda, but most of them flow down with rain. In This process the porous granite absorbes the dissolved salts with moisture into the inside by capillary action. In order to reduce this problem, therefore, white joint moral is changed with other less soluble materials. And it is necessary to take steps to prevent water from seep into the inside of the stone, because this water dissolves the white joint mortar.

• Journal of Conservation Science
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• v.31 no.4
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• pp.443-455
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• 2015

To verifying the stability of Natural pigments for Dancheong which is available on the market was carried out as light resistance and gas corrosion test. In this particular case, we will confirm the characteristics of the only pigments except of Dancheong technique and influence of substance. Medium using for coloring are animal glue and synthetic resin that widely used for Dancheong in currently. Selected to artificial light source is a xenon arc lamp, contaminated gas is nitrogen dioxide gas in experiment. Degree of degradation of pigment were compared by measuring the degree of color change. The result of light resistance test, mineral pigments were good; color is green and blue type, soil pigments also good; color is yellow ocher, white clay, red clay etc. Gamboge, unghwang, cinnabar, red lead were confirmed not good. The result of gas corrosion test, most of the natural pigments were good condition except the red lead. Generally, animal glue samples had better than a synthetic resin samples.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3983-3989
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• 2014

As the storm water runoff characteristics in urban areas have changed owing to urbanization, centralized facilities to reduce the urban flood runoff had been implemented. On the other hand, because they have their limitations, LID (Low Impact Development) of the distributed facilities for storm water runoff reduction is being actively planned and applied. The purpose of this study was to analyze the runoff characteristics for the spatial distribution of typical LID element techniques. This study set a study basin consisting of the five subbasins with the same basin and drainage systems, and analyzed the flood runoff characteristics from the two scenarios, one is for the locations and the other is for the number of green roofs (GR) and permeable pavement (PP), respectively, selected as typical LID element techniques. The SWMM implementation results showed that GR reduces 11.07% of the total and 3.42% of the peak amounts of storm water runoff, and PP leads to 18.09% of the total and 17.94% of the peak discharge reduction for a subbasin. Such a reduction rate is constant regardless of the LID locations, and increases linearly with the number of LID applications. The different runoff reduction rates between the GR and PP applications appear to be due to the effects of the different hydraulic conductivities in the control parameters for each LID.

• Journal of Korea Water Resources Association
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• v.53 no.2
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• pp.89-96
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• 2020

Water management agencies under the Ministry of Environment produce and accumulate qualified basic data for major rivers. However, the integrated management of the river water has been weak since the artificial water circulation process, such as the intaking and drainage of agricultural water, has not been examined in the basin, which includes many agricultural land. In this study, a study was conducted on how the power usage method (operating time method) based on the running time can be applied and improved among indirect flow rate measurement methods used to investigate flow rates collected by the riverside for agricultural water purposes, and thus the resultant data of high reliability can be obtained at low cost. The operation time method is suitable for small-scale water pumping stations where it is difficult to secure real-time power supply data. The reliability of the data was verified through the correlation analysis with the actual flow rate, and it was found that the flow rate calculated by the operation time method reflecting the level of the stream to which the inlet of the pumping station is connected can be reasonably matched with the actual flow rate. In addition, it was confirmed that the investment cost at the time of initial installation of the facility was highly efficient by generating qualified flow data at low cost through comparison with direct flow rate measurement methods. If flow data is secured by applying the operation time method to large and small water farms located along the riverside, it is expected that more quantitative and integrated stream water management will be possible.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.82-89
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• 1981

The characteristic of rainfall intensity in short duration is very important to calculate short-term runoff in small watershed by Rational method. Therefore, the purpose of this study is to derive the most proper formula on the probable rainfall intensity in each return period in Daejeon area. And the results of this study could be utilized for the design of drainage-structures in small watershed, drainage system in urban area and flood control in small river basin. The result s of this study are summerized as follows. 1. Gumbel-Chow method which shows the mean value was chosen to calculate the probable rainfall in tensity in each return periods. 2. According to statistical judgement, probable rainfall intensity formula of Japanese type($I={\frac{a}{t+b}}$, see Table-6) shows the most proper one among other types of formula like Talbot type, Sherman type and Characteristic coefficient method. Probable rainfall in tensity value of Japanese type in Daejeon area shows well coincidence with the one obtained by applying prof. Park's n-coefficient to Monobe formula $I=({\frac{R_{24}}{24}})({\frac{T}{t}})^{0.5486}$. On the other hand, the value by Monobe formula with n-coefficient of 2/3 which is being used as a disign criterison by M. O. C. shows large difference from the fore-mentioned results (see Table-7). Consequently the value by Monobe formula might be judged that it is too much overestimated one as a design criterion. 3. Short-term runoff in small water shed could be calculated more reasonably in Daejeon area through this probable rainfall in tensity formula.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.2
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• pp.57-65
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• 2003

Mapping of salinity distribution in the reclaimed lands was attempted by using the electromagnetic inductance technique. Field study was conducted to monitor ground conductivity with an electromagnetic inductance, EM 38 (Geonics), and electrical conductivity of the saturated extract, ECe of the soils, at the Daeho reclaimed land. EM values of horizontal mode, EMh, and vertical mode, EMv, mode were recorded at the interval of $2m{\times}2m$ from the ground. Soil samples were taken through the profile down to 100cm for calibration. ECe of poor drained area of Daeho, were in the range of $19.50-91.50ds\;m^{-1}$, while ECe of well-drained area ranged from $1.10-34.40ds\;m^{-1}$. Multiple regression equations for the measured EMv, EMh, and ECe were highly significant. The EMh showed higher correlation with ECe than EMv. With the multiple equation, ECgM could be calculated. Correlation between ECe and ECgM was the highest ($r=0.753^{***}$), when EMI readings were taken on the ground. The relationships were highly significant below 30 cm height of measurement, With the EM38 measurement, the salinity distribution was effectively expressed for the experimental filed in Daeho reclaimed land.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.196-202
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• 2005

This research was conducted to determine the amount of water absorbed by a polyacrylamide hydrogel such as Stocksorb C (STSB), effect of salts on inhibition in hydration of STSB, and the hydrogel effects on changes of nutrient concentration in external solution. Absorption of deionized water by STSB reached a maximum of 180 $mL{\cdot}g^{-1}$. Monovalent soluble salts such as $KH_2PO_4,\;KNO_3$, and $(NH_4)_2SO_4$ reduced absorption of the hydrogel, but the degrees of inhibition in absorption were similar in three kinds of salts. Twenty milliequivalents per liter of $Ca_{2+}\;or\;Mg_{2+}$ reduced water absorption of STSB to $14\%$ compared to those of deionized water. Solution absorption was consistently lower in the presence of divalent cations than in the presence of the monovalent cations. But the absorption was unaffected by the uncharged salt such as urea in all concentrations tested. The final $K^+\;and\;NH_4^+-N$ concentrations of the solution remaining after absorption by STSB was higher than those of the initial solution. The soaking of STSB to full strength of Hoagland solution resulted in increase of $NO_3^--N,\;H_2PO_4^-\;and\;SO_4^{2-}$ concentrations in external solution compared to initial solution, reaching 5,300, 250 and 1,500 $mL{\cdot}g^{-1}$, respectively, at 24 hrs after soaking.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.92-102
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• 2020

Porous pavement (PP) has attracted attention as a new alternative measure against road traffic noise. PP refers to pavement that reduces the fines in the asphalt mixture to form voids. These voids can reduce traffic accidents and friction noise. For active application, verification of the noise reduction effect is required. In this study, the noise reduction of single-layer PP(SLPP) and double layer PP(DLPP) was analyzed. First, the Sejong section was selected, and traffic noise was measured using the SPB method on the roadside. The traffic volume, speed, and mixing ratio of large vehicles were measured. As a result, the DLPP was evaluated to be 7.95 dB(A) smaller on average and 7.57dB(A) smaller at the 95% reliability level than the SLPP. The traffic volume was more influential than the speed and the mixing rate of large vehicles. As the traffic volume increased, the noise increased, but the difference in noise between the two pavements decreased gradually. The results showed that the most effective way to reduce road traffic noise is to change the road pavement rather than reduce traffic speed, restrict traffic for heavy vehicles, or reduce traffic volume.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.809-813
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• 2004

강우시 유역 내에서 발생하는 수문특성을 구명하고자 하는 연구는 지속적으로 진행되고 있다. 특히 최근 몇년간 집중호우로 인한 홍수피해가 매우 실각한 수준으로 발생하였고, 이에 지방 소하천을 포함한 전국의 하천정비사업이 새로운 설계홍수빈도를 토대로 진행되고 있다. 우리나라의 강우특성은 여름철에 편중되는 특성을 지니고 있어 홍수시의 홍수방어 대책 등 치수에 많은 어려움이 있는 것이 현실이다. 집중호우로 인한 피해는 전 세계적인 문제로 제기되고 있으며, 이에 강우-유출 관계를 규명하고자 하는 노력이 지속적으로 이루어지고 있다. 강우-유출과정은 시간적, 공간적 다변성을 지닌 수문학적 인자에 의해 좌우되기 때문에 이러한 문제를 해결하기 위해 다년간의 강우-유출 자료를 바탕으로 알고리즘을 생성하고, 이를 바탕으로 정확한 모의가 가능한 수문 모형 및 시스템들을 개발하는데 노력을 기울이고 있다(심순보 등, 1998, 신사철 등, 2002). 그러나 이러한 모형들은 많은 매개변수와 다양한 정보들을 필요로 하게 되어 이들을 처리하는데 많은 어려움이 따른다. 따라서 최근에는 GIS(Geographical Information System)를 활용하여 유역과 분수계를 결정하고 하천형태학적인 특성인자를 추출하는 자동화된 유역정보 추출기술 개발에 대한 관심이 집중되고 있다(Bhaskar, 1992, Francisco, 1995, Yeon, 1999). 이에 본 연구에서는 GIS기법을 이용하여 지형자료로부터 하천연장, 배수면적, 지체시간, 도달시간 등 유역내의 분포형 수문매개변수를 추출하였고 추출된 매개변수를 통해 강우-유출식을 적용하여 분포형 유출량을 산정하는데 활용하고자 한다.ansverse Mercatro) 지구좌표계의 DEM 자료로 변환하였다. 또한 유역의 고도차를 이용한 흐름특성 분석을 위해 수치고도자료를 이용하여 유역흐름특성을 분석할 수 있는 TOPAZ(Topographic PArameteri-Zation) 프로그램을 이용하였다. TOPAZ 프로그램을 통해 분석된 각 격자별 분포형 수문 매개변수는 적합한 관계식을 통해 분포형 유출량을 모의하는데 적용된다.다 정확한 유입량 예측이 가능할 것으로 사료된다.이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유

• Journal of Korea Water Resources Association
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• v.51 no.4
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• pp.301-311
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• 2018

Recently, the flood inundation caused by heavy rainfall in urban area is increasing due to global warming. The variability of climate change is described in the IPCC 5th report (2014). The precipitation pattern and hydrological system is varied by climate change. Since the heavy rainfall surpassed the design capacity of the pipeline, it caused great damage in metropolitan cities such as Seoul and Busan. Inundation in urban area is primarily caused by insufficient sewer capacity and surplus overflow of river. Inundation in urban area with concentrated population is more dangerous than rural and mountains areas, because it is accompanied by human casualties as well as socio-economic damage to recover destruction of roads, brides and underground spaces. In addition, various factors such as an increase in impervious area, a short time of concentration to outlet, and a shortage of sewer capacity's lack increase flooding damage. In this study, flood inundation analysis was conducted for vulnerable areas using XP-SWMM. Also, three structural flood prevention measures such as drainage pipeline construction, detention reservoir construction, and flood pumping station construction are applied as flood damage prevention alternatives. The flood data for each alternative were extracted by dividing the basin by grid. The Spatial Compromise Programming are applied using flood assessment criteria, such as maximum inundation depth, inundation time, and construction cost. The purpose of this study is to reflect the preference of alternatives according to geographical condition even in the same watershed and to select flood defense alternative considering regional characteristics.