• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.4
• /
• pp.75-81
• /
• 2016

This study focused on exploring real transaction price of apartment and spatial and temporal heterogeneity of the variables that influence real transaction price of apartment from the spatial and temporal perspective. As independent variables that are considered to influence real transaction price of apartment, transport, local characteristics, educational conditions, population, and economic characteristics were taken into account. Accordingly, the influence of independent variables and spatial distribution pattern were analyzed from the global and local aspects. The spatial and temporal changing patterns of real transaction price of apartment which is a dependent variable were analyzed. First, to establish an analysis model, OLS analysis and GWR analysis were conducted, and thereby more efficient and proper model was selected. Secondly, to find spatial and temporal heterogeneity of independent variables with the use of the selected GWR model, Local $R^2$ was used for local analysis. Thirdly, to look into spatial distribution of independent variables, kriging analysis was carried out. Therefore, based on the results, it is considered that it is possible to carry out more microscopic housing submarket analysis and lay the foundation for establishing a policy on real property.

• Journal of Distribution Science
• /
• v.11 no.8
• /
• pp.31-37
• /
• 2013

Purpose - This study aims to strengthen the economic cooperation between Korea and Japan by studying the pattern of trade between them and identifying drawbacks. Thus, it aims to enable trade expansion by analyzing the factors that affect trade and identifying ways to improve them. If economic cooperation is improved, transport and communication costs, as well as the transaction cost of economic exchanges, can be minimized. Research design, data, methodology - The trade intensity index developed by the Japanese economist Yamazawa under his trade intensity theory was used to analyze the trade decision factor of Korea and Japan. Trade structure and decision factors were analyzed for the target period of 2000 to 2012, and the period ranging from 2000 to 2005 was compared with the period ranging from 2005 to 2012. This paper is an analysis of the resultant time series. The data were collected from Korea Traders Association, Korea Customs Office, and UN Comtrade (2000, 2005, 2012) and whole table indexes were calculated by the author. Trade related index was used to analyze the comparative advantage based on time-series analysis statistics data (2000. 2005, 2012) through an analysis of the trade intensity index (TII), revealed comparative advantage index (RCA), and trade specialization index (TSI). Results - The trade intensity index of the industries of Japan and Korea is 1.814 in 2000. The export ratio of Japan against China was slightly higher at 2.128. TII is indicated to be 1.600 in both 2005 and 2012, which means export ratio of Japan against China is considerably maintained in 2005; however, export ratio of Japan against China is diminishing gradually as its index is 1.600 in 2012. Second, as per the trade specialization index of the ship industry in Japan and China, TSI is indicated to be -0.818 in 2000, -0.308 in 2005, and -0.847 in 2012. Generally, it is still closer to -1 and especially, we can see it is more closer to -1 in 2012. Third, as per the revealed comparative advantage index of the ship industry in Japan and China, the RCA index in 2012 is 0.007, which is quite far from 1 as compared to the value in 2000 and 2005. Hence, the Japanese ship industry has a significant comparative disadvantage against the Chinese ship industry. Conclusions - Both countries invest most of their capital in the shipping industry. It is the shipping industry that receives the most capital investment in the two countries is invested and governmental policy funds are needed. As both countries have large shipping industries, this research project is very valuable. Japan and China are compared because they are Korea's neighbors. Also, Korea is strategically located in Northeast Asia and has a history of foreign intrusion from several countries. Therefore, the purpose of this research study is to understand the trade structures of both countries and intensify the economic cooperation between Japan and China.

• Journal of Korean Society of Transportation
• /
• v.33 no.3
• /
• pp.256-267
• /
• 2015

The intelligent transportation systems allow us to have valuable opportunities for collecting wide-area coverage traffic data. The significant efforts have been made in many countries to provide the reliable traffic conditions information such as travel time. This study analyzes the impacts of the fog weather conditions on the traffic stream. Also, a strategy for predicting the long-term traffic speeds is developed under foggy weather conditions. The results show that the average of speed reductions are 2.92kph and 5.36kph under the slight and heavy fog respectively. The best prediction performance is achieved when the previous 45 pattern cases data is used, and the 14.11% of mean absolute percentage error(MAPE) is obtained. The outcomes of this study support the development of more reliable traffic information for providing advanced traffic information service.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.6
• /
• pp.1329-1338
• /
• 2015

This article aims to develop model for the right policy Tools available from the cause analysis regarding the regional differences of subway modal split in Seoul metropolitan area. This allows two major factors of the most influential subway modal split to be proved and Portfolio Analysis is conducted. The results are as follows. Firstly, the two primary factors affecting subway modal split were shown as subway adjacent area and local line bus. It signifies that expansion of subway adjacent area, establishing the number of the subway stations and increase of local line bus are required in order to improve a diminishing subway modal split. Following that, pattern of the improvement to strengthen better subway connections are classified according to the two areas which are Concentration Area of Improvement in Subway Station Area (CAISSA) and Concentration Area of Improvement in Local Bus (CAILB). Our study revealed that Ganbukgu, Seodaemungu, Geumcheongu, and Gwanakgu were selected as the area of CAILB and Songpagu, and Junggu were selected as the area of CAISSA. As all things are considered, transportation policy makers should be taken into account in the two main factors driven by our study according to types in order to enhance the future subway share proportion.

• Journal of the Korean earth science society
• /
• v.23 no.7
• /
• pp.565-574
• /
• 2002

Based on previous investigations of aerial photographs and topographical surveys, this study focuses on the sedimentologic features of the Daebudo area including sedimentation processes, sedimentary facies and hydrologic conditions of the erosional coast. A total of 137 surface sediments and one core (by hand auger) sediment were obtained to interpret the depositional environment of the erosional coast in the macro-tidal coast. Surface sediments are distributed from sandy gravel (sG) to silt (Z). Textural parameters are characterized not only by coarse, poorly sorted, positive skewed and multi-modal distribution in the supra-tidal flat, but also finer, relatively well-sorted, symmetric distribution in the intertidal flat. According to the C/M diagram, sediment transport modes of study area are characterized by the mixed mode of suspension and bedload in the upper-, middle-tidal flat and by uniform suspension in the lower-tidal flat due to tidal effect. Vertical sediment distribution of the core, collected near shoreline, shows coarsening-upward, poorly sorted pattern by the input of detritus resulting from coastal erosion. Considering the sedimentological features of the study area, it appears to be composed of a coastal zone changed by not only artificial reclamation, but also by natural processes such as strong wave action due to typhoons and storms during high water level and long/short-term sea level rising. As a result, tide-dominated erosional coasts show that the shore is affected by local, temporal and hydrological conditions near high tide level and that the intertidal flat is represented by a general tide-dominated sedimentary environment.

• Journal of Environmental Science International
• /
• v.19 no.12
• /
• pp.1343-1354
• /
• 2010

The purpose of the study was to analyze the persistence of HCH in atmosphere, soil, sediment and water of the western and southern regions of Korea. The samples from the western region were collected from Anmyeon Island, and the samples from the southern region were collected from Kimhae and Busan. The concentration of HCH isomers in atmosphere showed the pattern of $\alpha$-HCH>$\gamma$-HCH>$\beta$-HCH. The regions with high HCH concentration in the atmosphere are the regions that have been highly exposed to HCH used in the past, and the areas that have been influenced by the long range transport. The HCH that persists in the soil, water and sediment evaporates into the atmosphere, showing the characteristics of Air-Surface exchange. When the regional concentration distributions are compared, the concentration of HCH was higher in the atmosphere of a plain and the cities near the plain, than the urban areas. In this study, the ratio of $\alpha/\beta$-HCH was used as an indicator for estimating the source of Technical HCH and Lindane. According to the result, the contribution of Lindane was high in Kimhae plain and Kimhae urban areas. However, in Busan, the contribution of Technical HCH was higher than Lindane. In case of Anmyeon Island, the western region of Korea had high contribution from Tehcnical HCH. In soil and sediment, $\beta$-HCH was dominant. In water, $\gamma$-HCH was dominant among other isomers. Such results are due to $\gamma$-HCH inLindane. Furthermore, the source of $\gamma$-HCH in urban areas is assumed to be the use of medicine, medical supplies and other living supplies. Based on the results of this study, the management of HCH, a newly list up emerging POPs, should be strengthened by further research on sources, fate, persistency, accumulation and exposures and etc. to the risk assessments.

• Journal of Environmental Health Sciences
• /
• v.44 no.2
• /
• pp.143-152
• /
• 2018

Objectives: The purpose of this study was to provide basic data for air pollutant exposure modelling and understanding the contribution of respective microenvironments by assessing the time-activity patterns of Korean students according to variables such as grade, sex, weekday, and weekend. Methods: In this study, we compared the residential time of 521 (both weekday and weekend) lower elementary students, 1,735 (1,054 on weekdays, 681 on weekends) upper elementary students, 2,210 (1,294 on weekdays, 916 on weekends) middle school students, and 2,366 (1,387 on weekdays, 979 on weekends) high school students in different microenvironments according to grade, sex, weekday, and weekend. We used data from the 2014 Time-Use Survey by the Korean National Statistical Office for upper elementary students through high school students, and surveyed time-activity patterns of 521 lower elementary students aged 7-9 years. Each microenvironment was divided into indoor, outdoor, and transport. Indoor environments were divided into home, school, and other places. In addition, the results of previous studies were compared to this study. Results: Weekday time-activity patterns of Korean students indicated that lower elementary students spent $16.02{\pm}2.53hr$ in the home and $5.37{\pm}2.32hr$ in school. Upper elementary students spent $14.11{\pm}1.79hr$ in the home and $6.27{\pm}1.37hr$ in school. Middle school students spent $12.83{\pm}2.22hr$ in the home and $7.48{\pm}1.88hr$ in school. High school students spent $10.65{\pm}2.86hr$ in the home and $10.23{\pm}2.86hr$ in school on weekdays. High school students spent the least amount of time in the home and the most time in school compared to other grades Conclusions: Students spent most of their time indoors, including in the home, school, and other indoors. On weekdays, as the grade increases, home residential times were decreased and school residential times were increased. Differences in time-activity patterns according to sex were not found for either weekdays or weekends. It is estimated that Korean students could be affected by school indoor air quality. High school students could be most affected by school indoor air quality since they spent the most time at school.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.26 no.6
• /
• pp.405-412
• /
• 2014

A number of algal bloom models (red-tide models) have been developed and applied to simulate the redtide growth and decline patterns as the interest on the phytoplankton blooms has been continuously increased. The quantitative error analysis of the model is of great importance because the accurate prediction of the red-tide occurrence and transport pattern can be used to setup the effective mitigations and counter-measures on the coastal ecosystem, aquaculture and fisheries damages. The word "red-tide model" is widely used without any clear definitions and references. It makes the comparative evaluation of the ecological models difficult and confusable. It is highly required to do the performance test of the red-tide models based on the suitable classification and appropriate error analysis because model structures are different even though the same/similar words (e.g., red-tide, algal bloom, phytoplankton growth, ecological or ecosystem models) are used. Thus, the references on the model classification are suggested and the advantage and disadvantage of the models are also suggested. The processes and methods on the performance test (quantitative error analysis) are recommend to the practical use of the red-tide model in the coastal seas. It is suggested in each stage of the modeling procedures, such as verification, calibration, validation, and application steps. These suggested references and methods can be attributed to the effective/efficient marine policy decision and the coastal ecosystem management plan setup considering the red-tide and/or ecological models uncertainty.

• Korean Journal of Remote Sensing
• /
• v.34 no.5
• /
• pp.763-775
• /
• 2018

In this study, the effects of wind fences on the dispersion of the particles emitted from a constructing site located in the building-congested area in Busan, Korea, using geographic information system (GIS) and a computational fluid dynamics (CFD) model. We averaged the wind speeds observed for 10 years at the Busan automated synoptic observing system (ASOS) and we used the averaged wind speed as the wind speed at the reference height (10 m above the ground level). The numerical simulations were performed for 16 inflow directions, before and after the construction of wind fences with the heights of 5 m and 10 m (total 48 simulations). The detailed flows were analyzed for the northeasterly and south-southwesterly cases which predominantly observed at the Busan ASOS. In the northeasterly case, high concentration appeared at the elementary school next to the construction site due to transport by the airflow coming from the northeast. In the 5-m wind fence case, the wind speeds were slightly weaker and the spread of the fugitive dust was slightly less than those in the no wind fence case. In the 10-m wind fence case, the dust concentration at the elementary school has the maximum reduction of 37%. In the south-southwesterly case, the flow pattern became complicated in the construction site due to the terrain and buildings. Fugitive dust was stagnant at the south side of the construction site but rather spread to the north, increasing the concentration at the elementary school. After the wind fence was built, the concentrations inside the construction site became high as the wind speeds decreased inside, but, the concentrations in the elementary school rather decreased.

• Korean Journal of Soil Science and Fertilizer
• /
• v.36 no.1
• /
• pp.32-40
• /
• 2003

To characterize diel pattern of methane transport via rice plant, methane emission was measured on specific days in rice growing stages; tillering, meiotic, heading and harvest stages, from a paddy under different water management and organic amendments. Methane emission was monitored every two hours a day from chambers with and without rice plants. Proportion of the rice plant-mediated methane emission at different stage increased till the maximum growth of LAI and dry weight, and decreased thereafter. The proportion of methane emission through rice plants on June 18-19 at tillering stage was 38.4, 36.5 and 64.3 percent for NPK, Rice straw compost, RSC, and rice straw on February, RS2, respectively. The proportion on July 30-31 at meiotic stage was 70.4, 74.3 and 74.4 percent for NPK, RSC and RS2, respectively. The proportion on August 20-21 at heading stage was 80.1, 84.5 and 74.8 percent for NPK, RSC and RS2, respectively. The proportion on September 28-29 at harvest stage was 69.9, 65.9 and 64.4 percent for NPK, RSC and RS2, respectively.