• Radiation Oncology Journal
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• v.12 no.3
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• pp.393-399
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• 1994

Spinal cord compression, an oncologic emergency, is a rare complication of hematologic malignancy Our experience was obtained with a series 32 Patients following retrospective analysis for assessing the role of radiation therapy and identifying the prognostic factors affecting on treatment outcome. Diagnosis was usually made by means of radiologic study such as myelography or computerized tomography (CT) or magnetic resonance imaging (MRI) and neurologic examination. Five cases were diagnosed by subjective symptom only with high index of suspicion. In 31 cases, the treatment consisted in radiation therapy alone and the remained one patient had laminectomy before radiation therapy because of diagnostic doubts. Total treatment doses ranged from 800 cGy to 4000 cGy with median of 2000 cGy. Initially large fraction size more than 250 cGy were used in 13 patients with rapidly progressed neurologic deficit. The clinical parameters considered in evaluating the response to treatment were backache, motor-sensory performance and sphincter function. Half of all patients showed good response. Partial response and no response were noted in $37.5\%$ and $12.5\%$, respectively. Our results showed higher response rate than those of other solid tumor series. The degree of neurologic deficit at that time of diagnosis was the most important predictor of treatment outcome. The elapsed time from development of symptoms to start of treatment was significantly affected on the outcome. But histology of primary tumor total dose and use of initial large fraction size were not significantly affect on the outcome. These results confirmed the value of early diagnosis and treatment especially in radiosensitive hematologic malignancy.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.41-59
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• 2022

In accordance with the enactment of 'the Paris Agreement' in 2015 and 'the Framework Act on Carbon Neutrality and Green Growth for Response to the Climate Crisis' in 2021, each local government has set appropriate reduction target of greenhouse gas to achieve the nationally determined contribution (NDC, the reduction target of 40% compared to 2018) of greenhouse gas (GHG) emissions in 2030. In this study, the current distribution of GHG emissions was analyzed in a time series centered on the Chungbuk region for the period from 1990 to 2018, with the aim of reducing GHG emissions in Chungbuk by 2030 based on the 2030 NDC and scenario. In addition, the prospected reduction by 2030 was estimated considering the projected emissions according to Busines As Usual in order to achieve the target reduction of GHG emissions. Our results showed that GHG emissions in Chungbuk and Korea have been increasing since 1990 owing to population and economic growth. GHG emissions in 2018 in Chungbuk were very low (3.9 %) relative to the national value. Moreover, emissions from fuel combustion, such as cement and lime production, manufacturing and construction industries, and transportation industries, were the main sources. Furthermore, the 2030 target of GHG emission reduction in Chungbuk was set at 40.2% relative to the 2018 value, in accordance with the 2030 NDC and 2050 carbon-zero national scenario. Therefore, when projected emissions were considered, the prospected reduction to achieve the target reduction of GHG emissions was estimated to be 46.8% relative to 2018. The above results highlight the importance of meeting the prospected reduction of GHG emissions through reduction means in each sector to achieve the national and local GHG reduction target. In addition, to achieve the 2030 NDC and 2050 carbon zero, the country and each local government, including Chungbuk, need to estimate projected emissions by year, determine reduction targets and prospect reductions every year, and prepare specific means to reduce GHG emissions.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.40-50
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• 2024

Pine forests are continuously declining due to competition with broadleaf trees, such as oaks, as a consequence of changes in the natural dynamics of forest ecosystem. This natural decline creates a risk of losing the various benefits pine trees have provided to people in the past. Therefore, it is necessary to prepare future forest management directions by considering the state of pine tree decline in each region. The goal of this study is to understand the characteristics of pine forest changes according to forest dynamics and to predict future regional changes. For this purpose, we evaluated the trend of change in pine forests and extracted various variables(topography, forest stand type, disturbance, and climate) that affect the change, using time-series National Forest Inventory (NFI) data. Also, using selected key variables, a model was developed to predict future changes in pine forests. As a results, it showed that the importance of pine trees in forests across the country has decreased overall over the past 10 years. Also, 75% of the sample points representing pine trees remained unchanged, while the remaining 25% had changed to mixed forests. It was found that these changes mainly occurred in areas with good moisture conditions or disturbance factors inside and outside the forest. In the next 10 years, approximately 14.2% of current pine forests was predicted to convert to mixed forests due to changes in natural forest dynamics. Regionally, the rate of pine forest change was highest in Jeju(42.8%) and Gyeonggi(26.9%) and lowest in Gyeongbuk(8.8%) and Gangwon(13.8%). It was predicted that pine forests would be at a high risk of decline in western areas of the Korean Peninsula, including Gyeonggi, Chungcheong, and Jeonnam. This results can be used to make a management plan for pine forests throughout the country.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.19-32
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• 2007

In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

• Journal of Service Research and Studies
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• v.6 no.2
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• pp.99-116
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• 2016

The purpose of this paper is to see what the problem is and what the direction of the strategy of asset management after this study has analyzed asset management status of domestic life insurance companies according to interest rate trends, analyzing in time series management asset lists, asset distribution state, and securities list of life insurance companies during 2000~2014. It has carried correlation analysis and regression analysis between yield and bond interest KOSPI index. As the study result, life insurance companies have managed assets in stability than profitability. The correlation coefficient between interest rate and performance rates of total asset, management asset and securities is highly plus, correlation of management asset performance rate is higher than that of total asset performance rate, and the correlation of securities performance rate is higher than that of management asset performance rate. The correlation coefficient of KOSPI and performance rate shows minus. The suggestion is that the change of asset management is required as the interest decline rises up a reverse margin risk because of the asset management of stability.

• Spatial Information Research
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• v.22 no.4
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• pp.39-47
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• 2014

The Yeongsan river estuary has a serious water quality problem due to the water stagnation and it is imperative to predict the changes of water quality for mitigating water pollution. EFDC(Environmental Fluid Dynamics Code) model was mainly utilized to predict the changes of water quality for the estuary. The EFDC modeling normally accompanies the large volume of modeling output. For checking the spatial distribution of the modeling results, post-processing for converting of the output is prerequisite and mainly post-processing program is EFDC_Explorer. However, EFDC_Explorer only shows the spatial distribution of the time series and this doesn't support overlay function with other thematic maps. This means the impossible to the connection analysis with a various GIS data and high dimensional analysis. Therefore, this study aims to develop a post-processing system of a EFDC output to use them as GIS layers. For achieving this purpose, a editing module for main input files, and a module for converting binary format into an ASCII format, and a module for converting it into a layer format to use in a GIS based environment, and a module for visualizing the reconfigured model result efficiently were developed. Using the developed system, result file is possible to automatically convert the GIS based layer and it is possible to utilize for water quality management.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.45-59
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• 2006

In this study, the effects of the surface topographical characteristics on the meteorological fields are examined in a mesoscale meteorlolgical model. We calculated the direct solar radiation using the illumination angle considering the inclination of topography and tried to find out its effect on meteorological fields. In above experiments, we selected two cases for the clear day and the cloudy day to show the effect of weather and represented the results for two cases. In the correction of the direct solar radiation, the results of two cases indicate that there are obvious differences on the steep Taeback and Soback mountains. And on the time-series analysis the east-facing slope of these mountains receives the more direct solar radiation about $10-60W/m^2$ in the morning hours but lesser in the afternoon hours than the horizontal surface while it is opposite on the west-facing slope. And the results mentioned above are more obvious at clear day. With the same analysis method, at clear day, the surface skin temperature is higher at all hours than that on horizontal surface on the both of slope. At cloudy and rainy day, the surface skin temperature on the east-facing slope is higher in the morning hours but lower in the afternoon hours than that on horizontal surface. But on the west-facing slope, it is higher at all hours than that on horizontal surface. In the two cases, the temperature considering the slope of surface is almost higher than that on the horizontal surface. The wind is stronger than that on the horizontal surface with increasing pressure gradient force according as increasing temperature gradient around the Taeback and the Soback mountains.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.199-217
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• 2016

Influences of seasonal warming and cooling rates on the annual temperature patterns were analyzed based on the meteorological data from 13 weather stations in Busan Metropolitan Area(BMA), Korea during 1997~2014. BMA daily temperature time-series was generalized by Fourier analysis, which mathematically summarizes complex, regularly sampled periodic records, such as air temperature, into a limited number of major wave components. Local monthly warming and cooling rates of BMA were strongly governed by the ocean effect within the city. March($1.121^{\circ}C/month$) and November(-$1.564^{\circ}C/month$) were the two months, when the most rapid warming and cooling rates were observed, respectively during the study period. Geographically, spring warming rates of inland increased more rapidly compared to coastal areas due to weaker ocean effect. As a result, the annual maximum temperature was reached earlier in a location, where the annual temperature range was larger, and therefore its July mean temperature and continentality were higher. Interannual analyses based on average temperature data of all weather stations also showed that the annual maximum temperature tended to occur earlier as the city's July mean temperature increased. Percent area of impervious surfaces, an indicator of urbanization, was another contributor to temperature change rates of the city. Annual mean temperature was positively correlated with percent area of impervious surfaces, and the variations of monthly warming and cooling rates also increased with percent area of impervious surfaces.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.273-279
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• 2007

Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of an Arch Bridge. Component reliabilities of girders have been evaluated using the response surfaces of the design variables at the selected critical sections based on the maximum shear and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses lot this relatively small probability of failure of the complex structure, which is hard to be calculated by Monte-Carlo Simulations or by First Order Second Moment method that can not easily calculate the derivative terms in implicit limit state functions. For the analysis of system reliability, parallel resistance system composed of girders is modeled as a parallel series connection system. The upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts, compared with the previous permutation method or conventional system reliability analysis method.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.136-146
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• 1999

A series of experiments were carried out in winter to investigate the indoor thermal environment in greenhouses with different kinds of heating systems, and characterize the energy consumption, heat transport and thermal energy efficiency of each system. By the Quantitative calculation of heat losses which transmit through the covers of greenhouse, the fundamental data of energy-saving of the particular heating system were obtained. And from the analysis of air temperature differences between indoor and outside, it was possible to select more effective energy-saving and comfortable heating system in greenhouses. The electric heater was more stable in thermal environment and cheaper in cost, since it could be used during the surplus time of electric power from 10：00 p.M. to 8：00 A.M. But the low air temperature in greenhouses besides these times resulted in a chilling problem of the crops. The heating system by hot air had the advantage to show nearly uniform temperature difference by the height above the ground. But the system had the disadvantage to require more energy consumption than the electric heating system.