• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.405-414
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• 2008

To better understand the physical processes that control the high-latitude lower thermospheric dynamics, we analyze the divergence and vorticity of the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions. For this study the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEG CM) is used. The analysis of the large-scale vorticity and divergence provides basic understanding flow configurations to help elucidate the momentum sources that ulti-mately determine the total wind field in the lower polar thermosphere and provides insight into the relative strengths of the different sources of momentum responsible for driving winds. The mean neutral wind pattern in the high-latitude lower thermosphere is dominated by rotational flow, imparted primarily through the ion drag force, rather than by divergent flow, imparted primarily through Joule and solar heating. The difference vorticity, obtained by subtracting values with zero IMF from those with non-zero IMF, in the high-latitude lower thermosphere is much larger than the difference divergence for all IMF conditions, indicating that a larger response of the thermospheric wind system to enhancement in the momentum input generating the rotational motion with elevated IMF than the corresponding energy input generating the divergent motion. the difference vorticity in the high-latitude lower thermosphere depends on the direction of the IMF. The difference vorticity for negative and positive $B_y$ shows positive and negative, respectively, at higher magnetic latitudes than $-70^{\circ}$. For negative $B_z$, the difference vorticities have positive in the dusk sector and negative in the dawn sector. The difference vorticities for positive $B_z$ have opposite sign. Negative IMF $B_z$ has a stronger effect on the vorticity than does positive $B_z$.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.25-31
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• 2007

Characterizing the risk posed by a mixture of chemicals is a challenging task due to the chemical interactions of individual components that may affect their physical behavior and hence alter their exposure to receptors. In this study, cell tests that represent subsurface environment were carried out using benz[a]anthracene (BaA) and p-xylene focusing on phasetransforming interaction to verify increased mobility and risk of highly sorbed pollutants in the presence of less sorbed, mobile liquid pollutants. A transport model was also developed to interpret results and to simulate the same process on a field scale. The experimental results showed that BaA had far greater mobility in the presence of p-xylene than in the absence of that. The main transport mechanisms in the vadose zone were by dissolution to p-xylene or water. The transport model utilizing Defined Time Steps (DTS) was developed and tested with the experimental results. The predicted and observed values showed similar tendency, but the more work is needed in the future study for more precise modeling. The field-scale simulation results showed that transport of BaA to groundwater table was significantly faster in the presence of NAPL, and the oral carcinogenic risk of BaA calculated with the concentration in groundwater was 15${\sim}$87 times larger when mixed with NAPL than when solely contaminated. Since transport rate of PAHs is very slow in the subsurface without NAPL and no degradation of PAHs was considered in this simulation during the transport, the increase of risk in the presence of NAPL is expected to be greater for the actual contaminated site.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4523-4535
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• 2012

As a way to popularize Karatedo, a curriculum for developing excellent trainers is needed. For that, DACUM was used to specifically look into the field of duty and work that a Karatedo trainer should have, and the purpose of this study is to present fundamental data necessary for developing and organizing the curriculum of cultivating Karatedo and create a useful material that can contribute to improve Karatedo trainers' performances who are working on site. A survey using Likert scale's 7 stages was conducted on DACUM meeting data, 28 managers and 108 trainers. Based on the collected data, this study had a test in order to solve the presented subject using DACUM method and SPSS WIN Ver. 14.0. This core work through the requirements analysis process. And karate leaders the necessary knowledge, skills, and tools, and attitude analysis was carried out to perform the tasks of each. Knowledge, skills, tools and attitude for each task, toward the results of the analysis were 47 core tasks. 167 knowledge items, function 143 items, the tool 60 items, 16 attitude items reclassified a total of 18 subjects were derived. The configuration of the karate leader training program curriculum model 'Karate practical expert area', 'theory karate expert area', 'Karate gym business area experts' was composed. Basic process of how it works Step 1, Step 2 integration process, replenishment process intensified Step 3 was composed.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.44-56
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• 1993

The situation and the problems of the management of public forest owend by Kangweon provincial and Taebaek municipal govenments were investigated throughout literature and field survey. The results were as follows; 1. Kangweon provincial forest is 25,896ha and Taebaek municipal forest is 550ha, which consists of Kangweon provincial forest, 470ha and municipal forest, 80ha. Taebaek city is responsible for the management of the province-owned forest in its administrative district in addition to its own forest. 2. Except San 1-2Changjookdong (443ha) which is leased by Dai Han Coal. Coporation for mining coal, the remaining forest (107ha) consists of 32 scattered, small-area forest lands. 3. Due to small area and dispersal of municipal forest, the management base for forest production is not sound and the management at present is nearly absent. Based on these actual conditions, the following suggestions are provided for the rationalization for the municipal forest management. First, scattered, small-scale forests should be gathered to prepare a management complex. Second, the sustaining production of timber should be attained through the estblishment of systematic management plan. Third, the reasonable system for forest land utiliztion shoule be established in consideration of the recreational use of public forest.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.287-298
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• 1992

The main purpose of this study is to obtain information on the factors influencing forest scenic beauty in order to make and manage scenic forest of recreation areas. 62 slides were taken for the study. Each photograph was independently judged by college students in 10 different major fields, with a total 264 observers after reliability test in the study. The ratings were scaled using a computer program developed by Brown & Daniel(1990). The results of rating scale analysis indicate that respondents' major field difference affects visual preference for forest scenic beauty. Similarly, with different sexual, forest visit frequency, and community type in childhood, people tend to rate their preference differently. The respondents' rating scale of relative scenic beauty of near-view forest scenes can largely be explained in terms of forest physical characteristics of forest landscape. Bare ground area and stash area are represented negative esthetic effects, while DBH, number of trees per hectare, sky area showed positive esthetic effects. These 6 variables in the model can be accounted for 74% of total variance in perceived forest scenic beauty. With this study result, it can be concluded that forest physical characteristics are significantly related to visual preference for near-view forest scenes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.1
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• pp.1-12
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• 2022

Wind tunnel test for a small scale electric ducted fan with a 104mm diameter was conducted to analyze the aerodynamic characteristics when it was used as a propulsion system of tilt-propeller UAV. Experimental conditions were derived from flight conditions of a sub-scaled OPPAV. Forces and moments of the ducted fan model were measured by a 6-axis balance and 3-dimensional wake vectors which could induce an aerodynamic influence in the vehicle were measured by 5-hole probes. Thrust and torque on hover and cruise conditions were measured and analyzed to drive out the operating conditions when it was applied in the sub-scaled OPPAV. On transition conditions, thrust keep its value with tilt angle variation below 40° and increase after that. But, sideforce increase constantly until 75°. The maximum axial velocity in the wake on hover and cruise conditions was around 60m/s and tangential velocity was around 12m/s. The position of the maximum axial velocity and vortex center move off the fan rotation center line as the tilt angle increases.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.467-476
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• 2013

With increasing interest in environmental issues and the quality of surface water becoming inadequate for water supply, the Korean government has launched a groundwater development policy to satisfy the demand for clean water. To drive this policy effectively, it is essential to guarantee the accuracy of sustainable groundwater yield and groundwater use amount. In this study, groundwater use was monitored over several years at various locations in Korea (32 cities/counties in 5 provinces) to obtain accurate groundwater use data. Statistical analysis of the results was performed as a method for estimating rational groundwater use. For the case of groundwater use for living purposes, we classified the cities/counties into three regional types (urban, rural, and urban-rural complex) and divided the groundwater facilities into five types (domestic use, apartment housing, small-scale water supply, schools, and businesses) according to use. For the case of agricultural use, we defined three regional types based on rainfall intensity (average rainfall, below-average rainfall, and above-average rainfall) and the facilities into six types (rice farming, dry-field farming, floriculture, livestock-cows, livestock-pigs, and livestock-chickens). Finally, we developed groundwater-use estimation equations for each region and use type, using cluster analysis and regression model analysis of the monitoring data. The results will enhance the reliability of national groundwater statistics.

• Journal of Korean Society of Rural Planning
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• v.13 no.3
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• pp.123-133
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• 2007

The purpose of this study is to develop the landscape resource assessment system(LRAS) to help evaluate the value of landscape resources(Jeju Island's Stonewall fencing farming land) for the introduction of direct payment system of the landscape preservation objectively and to applicate the model in the fields. Delphi survey on Jeju's stonewall experts shows that the order of priority among value evaluation elements on Jeju's stonewall is its harmony with surroundings(34%), the preservation of its original state(34%) and its density and scale(32%). Evaluation system development of landscape resources(Jeju's stonewall fencing filming land) and field observation survey utilizing it consists of the following five steps. Step 1 includes the first Delphi survey on Jeju's stonewall experts to decide its value evaluation elements and their priority. Step 2 is the second Delphi survey on Jeju's stonewall experts to grade pictures of landscape resources(Jeju's stonewall fencing farming land) on the basis of expert-proposed value evaluation standards. Step 3 consists of analysis work using the result of Delphi survey on experts. Step 4 is to select five grade standard pictures according to each of three grading elements of A, B, C belonging to each of the three standards. Then, it is necessary to make panels including five A-grade pictures, five B-grade pictures and five C-grade pictures according to each of the three elements of density, harmony, and original state preservation. Step 5 consists of field observation survey. According to the result of few experts' value evaluation of stonewall fencing farming land with the aid of NRAS developed in this research, the area of Pyeongdae-ri is ranked first, and then the area of Bukcheon-ri, Chocheon-up, the area of Gwakgi-ri, Ewol-up, the area of Shinum-ri, Ewol-up and the area of Yongsu-ri, hankyung-Myun are ranked in the order named. When those areas are graded, A Grade Areas includes the areas of Pyeongdae-ri, the area of Bukcheon-ri, the area of Gwakgi-ri, B Grade Areas consist of the area of Shinum-ri and the area of Yongsu-ri, and the areas of Onpyeong, wimi and youngrak belong to C Grade Area.

• Journal of Korean Library and Information Science Society
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• v.51 no.1
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• pp.201-225
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• 2020

In order to respond to changes in college's educational goals and talents, university libraries need to be transformed into spaces that support creative and collaborative learning. Apart from overseas cases, it is necessary to discuss the development of creative and collaborative learning spaces appropriate to the situation of Korean university libraries. This purpose of this study is to provide an effective guide to university libraries planning to develop creative and cooperative learning spaces. To this end, this study conducted a literature review to define the concept of a creative and collaborative learning space in a university library, collected and analyzed cases of creative and collaborative learning space of Korean university libraries, and proposed a model for developing creative and collaborative learning space for university library. Case collection was carried out through field visits to 12 university libraries. In addition, in-depth interviews were conducted with the staffs in charge of the construction and operation of five university libraries selected in consideration of the operating entity, region, and scale. This study is meaningful in that it intensively researched and analyzed the advanced cases of creative and collaborative learning spaces in Korea to derive suggestions that can be used in the field of domestic university libraries.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.149-162
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• 2008

The Soil and Water Assessment Tool (SWAT) developed by the USDA-Agricultural Research Service for the prediction of land management impact on water, sediment, and agricultural chemical yields in a large-scale basin was applied to Daecheong Reservoir basin to estimate the amount of soil losses from different land uses. The research outcomes provide important indications for reservoir managers and policy makers to search alternative watershed management practices for the mitigation of reservoir turbidity flow problems. After calibrations of key model parameters, SWAT showed fairly good performance by adequately simulating observed annual runoff components and replicating the monthly flow regimes in the basin. The specific soil losses from agricultural farm field, forest, urban area, and paddy field were 33.1, $2.3{\sim}5.4$ depending on the tree types, 1.0, and 0.1 tons/ha/yr, respectively in 2004. It was noticed that about 55.3% of the total annual soil loss is caused by agricultural activities although agricultural land occupies only 10% in the basin. Although the soil erosion assessment approach adopted in this study has some extent of uncertainties due to the lack of detailed information on crop types and management activities, the results at least imply that soil erosion control practices for the vulnerable agricultural farm lands can be one of the most effective alternatives to reduce the impact of turbidity flow in the river basin system.