• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.637-644
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• 2016

This study sought to reevaluate the water supply capacities of the Nakdong river dams, and identify measures to remedy any shortages using weirs, focusing on 5 multipurpose dams and 8 weirs. The reevaluation of the dams was performed by the HEC-5 program using the original design criteria and inflow data recorded for each dam. The results show that the capacities of the 3 dams has decreased to 73~87%. Three simulations were performed to determine the effect of coordinating the dams and weirs. The first simulation was based on individual operation of the dams; the second on coordinated operation of the dams; and the third on coordinated operation of the dams and weirs. To obtain a water supply reliability of 95%, the annual water shortage was calculated for a 20-year period (1992~2011). In addition, long-term runoff simulation data used in the national river basin investigation by the Ministry of Land, Infrastructure and Transportation were used with the dam discharge data, because long-term inflow data for the weirs were not available. The simulations were performed by the HEC-ResSim program, with the reservoir network divided into 2 groups based on the Waegwan water station. The results show that water supply capacity for the 3 simulations to be $2424Mm^3/yr$, $2612Mm^3/yr$ and $2734Mm^3/yr$, respectively. This indicates that coordinated operation of the dams and weirs could provide an additional water supply of $122Mm^3/yr$.

• Journal of Mushroom
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• v.12 no.4
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• pp.275-279
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• 2014

Pleurotus pulmonarius usually grows on the dead wood of deciduous trees from mid summer to early fall. Cultivation of this mushroom is recently increasing due to its good flavour and fragrance. This study was conducted to find out the favorable substrate formulation in the bottle and bag cultivation of P. pulmonarius. The V formulation (10 : 50 : 20 : 20 mixing ratio of poplar sawdust, cottonseed hull, cottonseed meal and beet pulp) showed the fastest mycelial growth in the test tube column medium and highest yields in both bottle cultivation and bag cultivation. Those chemical conditions were pH 5.52, 29.07% organic matter contents, 1.12% total nitrogen, 25.95 OM/N ratio, 0.16% CaO, 0.51% $K_2O$, 0.17 MgO and 0.26 $P_2O_5$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.195-202
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• 2007

The normalized difference in incident solar energy between a target surface and a level surface (overheating index, OHI) is useful in eliminating estimation error of site-specific maximum temperature in complex terrain. Due to the complexity in its calculation, however, an empirical proxy variable called northern exposure index (NEI) which combines slope and aspect has been used to estimate OHI based on empirical relationships between the two. An experiment with real-world landscape and temperature data was carried out to evaluate performance of the NEI - derived OHI (N-OHI) in reduction of spatial interpolation error for daily maximum temperature compared with that by the original OHI. We collected daily maximum temperature data from 7 sites in a mountainous watershed with a $149 km^2$ area and a 795m elevation range ($651{\sim}1,445m$) in Pyongchang, Kangwon province. Northern exposure index was calculated for the entire 166,050 grid cells constituting the watershed based on a 30-m digital elevation model. Daily OHI was calculated for the same watershed ana regressed to the variation of NEI. The regression equations were used to estimate N-OHI for 15th of each month. Deviations in daily maximum temperature at 7 sites from those measured at the nearby synoptic station were calculated from June 2006 to February 2007 and regressed to the N-OHI. The same procedure was repeated with the original OHI values. The ratio sum of square errors contributable by the N-OHI were 0.46 (winter), 0.24 (fall), and 0.01 (summer), while those by the original OHI were 0.52, 0.37 and 0.15, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.1
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• pp.40-49
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• 2013

Current service system of the Korea Meteorological Administration (KMA) for blooming date forecasting in spring depends on regression equations derived from long term observations in both temperature and phenology at a given station. This regression based system does not allow a timely correction or update of forecasts that are highly sensitive to fluctuating weather conditions. Furthermore, the system cannot afford plant responses to climate extremes which were not observed before. Most of all, this method may not be applicable to locations other than that which the regression equations were derived from. This note suggests a way to replace the location restricted regression equations with a thermal time based phenology model to complement the KMA blooming forecast system. Necessary parameters such as reference temperature, chilling requirement and heating requirement were derived from phenology data for forsythia, azaleas and Japanese cherry at 29 KMA stations for the 1951-1980 period to optimize spring phenology prediction model for each species. Best fit models for each species were used to predict blooming dates and the results were compared with the observed dates to produce a correction grid across the whole nation. The models were driven by the KMA's daily temperature data at a 5km grid spacing and subsequently adjusted by the correction grid to produce the blooming date maps. Validation with the 1971-2012 period data showed the RMSE of 2-3 days for Japanese cherry, showing a feasibility of operational service; whereas higher RMSE values were observed with forsythia and azaleas.

• Journal of Korea Water Resources Association
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• v.49 no.4
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• pp.275-282
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• 2016

The objective of this study is to propose a new method to determine the drought event and the design drought severity. In order to define a drought event from precipitation data, theory of run was applied with the cumulative rainfall deficit. When we have a large amount of rainfall over the threshold level, in this study, we compare with the previous cumulative rainfall deficit to determine whether the drought is relieved or not. The recurrence characteristics of the drought severity on the specific duration was analyzed by the conditional bivariate copula function and confidence intervals were estimated to quantify uncertainties. The methodology was applied to Seoul station with the historical dataset (1909~2015). It was observed that the past droughts considered as extreme hydrological events had from 10 to 50 years of return period. On the other hand, the current on-going drought event started from 2013 showed the significantly higher return period. It is expected that the result of this study may be utilized as the reliable criteria based on the concept of return period for the drought contingency plan.

• Journal of Korea Water Resources Association
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• v.49 no.4
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• pp.283-291
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• 2016

As the infrastructures and populations are the condensed in the mega city, urban flood management becomes very important due to the severe loss of lives and properties. For the more accurate calculation of runoff from the urban catchment, hourly or even minute rainfall data have been utilized. However, the time steps of the measured or forecasted data under climate change scenarios are longer than hourly, which causes the difficulty on the application. In this study, daily rainfall data was disaggregated into hourly using the stochastic method. Based on the historical hourly precipitation data, Gram Schmidt orthonormalization process and K-Nearest Neighbor Resampling (KNNR) method were applied to disaggregate daily precipitation into hourly. This method was originally developed to disaggregate yearly runoff data into monthly. Precipitation data has smaller probability density than runoff data, therefore, rainfall patterns considering the previous and next days were proposed as 7 different types. Disaggregated rainfall was resampled from the only same rainfall patterns to improve applicability. The proposed method was applied rainfall data observed at Seoul weather station where has 52 years hourly rainfall data and the disaggregated hourly data were compared to the measured data. The proposed method might be applied to disaggregate the climate change scenarios.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.352-357
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• 2003

Volatile flavor compounds Angelica gigas Nakai and Angelica acutiloba Kitagawa were extracted by SDE (simultaneous steam distillation & extraction) using the mixture of n-pentane and diethylether (1:1, v/v) as an extract solvent and analyzed by GC-FID and GC-MS. The amount of essential oils of top part and root in Angelica gigas were obtained in 0.063% (v/w) and 0.389% (v/w) yields as a fresh weight base, respectively. The main compounds in top parts and the root were identified as nonane (7.51% and 24.49%, respectively), ${\alpha}-pinene$ (14.64% and 31.75%), limonene+${\beta}-phellandrene$ (14.01% and 9.66%), ${\gamma}-terpinene$ (7.85% and 1.20%), germacrene-d (5.85% and 0.22%), (E,E)-${\alpha}-farnesene$ (6.05% and 1.40%), ${\beta}-eudesmol$ (5.26% and 1.84%). Although these compounds were present in both parts. The results showed large differences in. the concentrations of them much varied. The amount of essential oils stem and leaf obtained (0.068% and 0.127% in A. gigas) and (0.153% and 0.243% in A. acutiloba) yields as a fresh weight base, respectively. More than 18 and 32 components in stem and leaf have been identified, which of main components in A. gigas were ${\alpha}-pinene$, myrcene, limonene, germacrene-d, eudesmol and butylphthalide, but germacrene-d and butylphthalide contents were also different in stem and leaf. And more than 21 and 32 components in A. acutiloba were ${\gamma}-terpinene$ and butylphthalide. Volatile compounds were very different in both species.

• Spatial Information Research
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• v.21 no.1
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• pp.45-52
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• 2013

Recently 3D surveying is recommended to manage underground facilities systematically before refilling of site operation. As the demand of realtime localization increases, cost reduction and consistent data construction which are realizable by using one man surveying method with unmanned target, are necessary for constructing DB of all sorts of the underground facilities with more speediness and correctness. This study sets a goal to develop a new type of surveying target which allows realtime localization to be performed by one man, through making an optimum reflector(triangle, quadrangle, and semispherical shape) by using the retro-reflection principle of optical prism which is being used for surveying currently. The new surveying target makes realtime surveying possible. To check reliability of its data, the accuracy is compared with surveying coordination of total station for each type in a quantitative method. In the result, the usefulness of the reflector for Underground Facilities localization is proved. Thus the foundation for underground DB construction conducted by one man is established for acquisition of 3D location information in more efficient way through using unmanned target.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.70-82
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• 2020

Recently, a lot of damages have been caused by urban flooding, and heavy rainfall that temporarily occur are the main causes of these phenomenons. The damages caused by urban flooding are identified as the change in the water balance in urban areas. To indirectly identify it, this research analyzed the change in the remote sensing indices on each land cover before and after heavy rainfall by utilizing daily precipitation data and multi-temporal Sentinel-2 satellite imagery. Cases of heavy rain advisory and warning were selected based on the daily precipitation data. And statistical fluctuation were compared by acquiring Sentinel-2 satellite images during the corresponding period and producing them as NDVI, NDWI and NDMI images about each land cover with a radius of 1,000 m based on the Seoul Weather Station. As a result of analyzing the maximum value, minimum value, mean and fluctuation of the pixels that were calculated in each remote sensing index image, there was no significant changes in the remote sensing indices in urban areas before and after heavy rainfall.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.3
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• pp.9-20
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• 2017

Camp Page, which has been located in front of Chuncheon Station for about 50 years since 1958, recently opened to the public. Chuncheon City is currently struggling to construct a park on this site due to an uncertainty of general plans and financial difficulties. Accordingly, this research conducted a cognitive survey about site usage with Camp Page users in order to clarify directions for efficient establishment of parks within the former military base. The course of research includes analytical methods such as a survey targeting Chuncheon citizens and tourists both in the field and online, a frequency analysis of 1,360 index samples, a cross analysis and t-test. As a result, firstly, Chuncheon citizens recognized the image of Chuncheon as a city with a fresh, clean lakeshore whereas tourists think of it as a city for sightseeing and leisure. Hence, it was justifiable to conclude that the city should organize various programs for people to enjoy leisure activities while at the same time protecting the environment. Second, the awareness of tourists about Camp Page was relatively low and both citizens and tourists recognize that it was not sufficient enough for enjoyment of free time. The majority answered "space for culture and art and for experiencing the natural environment" when asked about the direction of space creation at Camp Page, which indicates that the site will need to be available both for cultural art and nature experiences. Lastly, it was thought that the direction of developing leisure facilities in Chuncheon city should include the improvement of worn out installations and developing chain products among programs. This research will be able to use fundamental data for the efficient utilization of the returned U.S. military camps that are constantly merging.