• Journal of the Korean GEO-environmental Society
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• v.25 no.8
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• pp.5-11
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• 2024

Due to the high proportion of mountainous terrain in Korean territory and the concentration of heavy rainfall during the summer season, concerns arise about the potential decrease in slope stability caused by rainfall. Installing slope drainage facilities mitigates the rise in groundwater levels due to infiltration, thus enhancing slope stability. Horizontal drains, classified as auxiliary facilities among drainage systems, lack established installation standards and related research. Slopes with installed horizontal drains have been confirmed to exhibit higher safety factors compared to those without. Furthermore, the safety factor of mimicking horizontal drains by increasing the permeability coefficient of the surrounding ground was compared with that of the conventional simulation method using the Drain function. As a result of the comparison, it was confirmed that the installation length showed better drainage performance than the installation angle in the drainage performance of the horizontal drainage hole, and it was judged that the installation length was a more important factor.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.1
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• pp.94-106
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• 2011

The muddy water occurrence possibility of reservoir were analyzed by considering GIS based soil erosion model, sediment delivery ratio and effective reservoir capacity. For the purpose, the weakness factors for the establishment of countermeasures of basin were analyzed by evaluating input factors of RUSLE model based on spatial data such as DEM, soil map, landcover map and so on. The potential of soil erosion was estimated considering highland upland. The sediment yields of Chungju-Dam and Soyanggang-Dam showed the highest result in sediment yield using sediment delivery ratio with considering basin area. The sediment concentration of Imha-Dam and Chungju-Dam showed the highest value as 0.791 $kg/m^3/yr$ and 0.526 $kg/m^3/yr$ respectively in sediment concentration with considering effective reservoir capacity. Especially, sediment yield of Imha-Dam was about 2.36 times lower than Soyanggang-Dam, but the sediment concentration was 1.90 times higher preferably, because the effective reservoir capacity of Imha-Dam was about 4.48 times lower. This study calculated sediment concentration using the 10 years mean rainfall event and could consider the aspects of soil, terrain, landcover, cultivation condition and effective reservoir capacity of each basin effectively through the results. Therefore, these quantitative sediment concentration data could be used to estimate the potential of high density turbid water for reservoir and applied with effective tools for the management of reservoir.

• Journal of Distribution Science
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• v.11 no.2
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• pp.57-70
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• 2013

Purpose - The objective of this paper is to explain the successful methods for the revitalization of distribution and logistics of the least developed FEZs (Saemangum, Yellow-sea, and Deagu-Kyengbuk) in Korea. With the recent changes in the economic terrain of Northeast Asia as with the rise of China, Korea has developed a logistics hub concept for improving the efficiency of logistics and distribution industry and its distribution and logistics policy has received positive worldwide evaluation. Therefore, we face severe competition and must always look for ways to address these problems. Research design, Data, Methodology - This study adopts two methods to propose successful revitalization of distribution and logistics in the least developed FEZ. The first method investigates the limitation of these FEZs by analyzing the statutes, and the second one follows comparable cases. Thus, we first reviewed the efficient strategic political alternatives for the least developed FEZ, Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk, through the relative institution system, law, and future plans. Next, we studied the Bin-hai Economic Free Section (Zone) in China as a comparable example. In order to analyze the competitiveness of logistics in the three FEZs (Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk), the total factor productivity growth of regional manufacturing industries is divided into three sources: the external trade effect, scale effect, and technical change effect. However, this paper does not test for a positive contribution of external trade, which is a reason of non-building on these FEZs. A FEZ that shows a larger external trade effect than the others will have a comparative advantage in the logistics infrastructure and policy support. This study presented the newly applied Bin-hai FEZ in China, in order to make the studied FEZ as successful by applying the strategy of its distribution and logistics center. Results - In Korea, there is an increased focus on the benefit of the regional development of regions such as the Free Economic Zones (FEZ). We have six FEZs, Inchon, Busan-Jinhae, Guangyang, Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk. However, our FEZs do not have various supporting factors needed for the logistics and distribution industry. Korea designated the above six places as FEZ and has operated to enhance national competitiveness and ensure a balanced regional development since 2003. However, most FEZs did not receive favorable feedback in the first business performance evaluation and it is necessary to take action for substantial improvements. Conclusions - Especially, over the past 10 years, even though the FEZ policy has been implemented in an effort to promote success in distribution and logistics, there are still many underdeveloped industries in logistics. The main problem is the absence of revitalization of the high value added performance in the distribution and logistics industry. However, there is a limitation to this study. We have used non-empirical method based on a case study to arrive at our findings. Future studies should use appropriate statistical methods to supplement our results and provide a solution to this problem.

• Journal of Korean Society of Forest Science
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• v.82 no.2
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• pp.195-206
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• 1993

The purpose of this study is to provide a basis for establishing regional harvesting systems that ist the prerequisites for the forest mechanization. The factors restricting to the forest harvesting and logging methods from topographical aspects are studied for this purpose. Three main harvesting methods studied in this paper are : shortwood method, longwood method and full tree method. This study shows : the shortwood method is suitable for low, the longwood method for medium, the full tree method for high topographical conditions. For the logging methods, the focus of the study is on various ground based logging systems by animalpower, manpower, gravitation, wheeled & crawler vehicle and cable. The factors limiting the coverage of logging operation are slope and logging distance. The cable crane logging methods are classified by logging distance into short distance(to 300 or 400m), middle distance(to 700 or 800m) and long distance cable crane methods (over 700 or 800m). The wheeled vehicle method shows serious damages to forest resources, whereas the logging by log-line of the gravitation logging method and cable crane method tend to minimize such damages. The wheeled & crawler vehicle method also shows difficult to apply in the high slope conditions, whereas cable crane method can be applied to maximum 120% steep slope and uphill conditions.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.287-297
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• 2016

This study aims to identify the relationship between climatic factors and stand mean Diameter at Breast Height (DBH) for two major tree species; Pinus densiflora and Quercus mongolica in Andong-dam basin. Forest variables such as age, diameter distribution and number of trees per hectare from the $5^{th}$ and $6^{th}$ National Forest Inventory data were used to develop a DBH estimation model. Climate data were collected from six meteorological observatory station and twelve Automatic Weather System provided by Korea Meteorological Administration to produce interpolated daily average temperature map with Inverse Distance Weighting (IDW) method. Andong-dam basin reflects rugged mountainous terrain, so temperature were adjusted by lapse rate based correction. As a result, predictions of model were consistent with the previous studies; that the rising temperature is negatively related to the growth of Pinus densiflora whereas opposing trend is observed for Quercus mongolica.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.587-595
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• 2019

This study analyzed the influence of the environmental factor of each vegetation type in an urban, mountainous park (Tangeumdae Park in Chungju) on air ion. The measuring points were divided according to the tree species, diameter at breast height, crown density, and layered structure, and the meteorological factors and the air ion were measured. The results of the measurement showed the average generation of positive ions of $610.90{\pm}50.27ea/cm^3$, the average generation of negative ions of $723.58{\pm}64.25ea/cm^3$, and the air ion index of $1.19{\pm}0.10$. The results of the analysis, according to the vegetation type, are as follows. Firstly, the air ion varied according to the species, the chest diameter at breast height, and the layered structure, and was analyzed to be statistically significant. Secondly, the air ion and the vegetation type showed a positive correlation with the species, diameter at breast height, crown density, and layered structure. The cation showed a negative correlation with the species, diameter at breast height, and the crown density, and the anion showed a positive correlation with the species, the diameter at breast height, crown density, and layered structure. Thirdly, the ion index in ridges had a higher correlation with the vegetation type than the meteorological factors. In detail, the correlation was higher in the species > layered structure > crown density > diameter at breast height. This study had the limitation of evaluating air ions in the ridge. Therefore, future studies on air ion should consider both terrain structure and vegetation type and analyze the seasonal changes and comparison.

• Korean Journal of Remote Sensing
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• v.35 no.2
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• pp.299-316
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• 2019

The purpose of this study was to analyze landslide susceptibility in the Pyeongchang area using Weight of Evidence (WOE) and Evidential Belief Function (EBF) as probability models and Artificial Neural Networks (ANN) as a machine learning model in a geographic information system (GIS). This study examined the widespread shallow landslides triggered by heavy rainfall during Typhoon Ewiniar in 2006, which caused serious property damage and significant loss of life. For the landslide susceptibility mapping, 3,955 landslide occurrences were detected using aerial photographs, and environmental spatial data such as terrain, geology, soil, forest, and land use were collected and constructed in a spatial database. Seventeen factors that could affect landsliding were extracted from the spatial database. All landslides were randomly separated into two datasets, a training set (50%) and validation set (50%), to establish and validate the EBF, WOE, and ANN models. According to the validation results of the area under the curve (AUC) method, the accuracy was 74.73%, 75.03%, and 70.87% for WOE, EBF, and ANN, respectively. The EBF model had the highest accuracy. However, all models had predictive accuracy exceeding 70%, the level that is effective for landslide susceptibility mapping. These models can be applied to predict landslide susceptibility in an area where landslides have not occurred previously based on the relationships between landslide and environmental factors. This susceptibility map can help reduce landslide risk, provide guidance for policy and land use development, and save time and expense for landslide hazard prevention. In the future, more generalized models should be developed by applying landslide susceptibility mapping in various areas.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.420-430
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• 2001

The object of this study is to develop a computer program for the arrangement of the forest-road network maximizing the investment effect in forest-road construction with factors such as terrains, forest physiognomy, management plan, logging system, cost of forest-road construction, capacity of inputted labour, capacity of timber production and so on. The operating system developed by this study is Korean Windows 95/98 and Microsoft Visual Basic ver. 5.0. User interface was designed as systematic structure, it is presented as a kind of GUI(graphic user interface). The developed program has result of the most suitable forest-road arrangement, has suitable forest-road density calculated with cost of logging, cost of forest-road construction, diversion ratio of forest-road, cost of walking in forest. And the most suitable forest-road arrangement was designed for forest-road arrangement network which maximized investment effect through minimizing the sum of cost of logging and cost of forest-road construction. Input data were divided into map data and control data. Digital terrain model, division of forest-road layout plan, division of forest function and the existing road network are obtained from map data. on the other hand, cost of logging related terrain division, diversion ratio of forest-road and working road, cost of forest-road construction, cost of walking, cost of labor, walking speed, capacity of inputted labor, capacity of timber production and total distance of forest-road are inputted from control data. And map data was designed to be inputted by mesh method for common matrix. This program can be used to construct a new forest-road or vice forest-road which compensate already existing forest-road for the functional forestry.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.2
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• pp.72-78
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• 2009

The demand for rainfall data in gridded digital formats has increased in recent years due to the close linkage between hydrological models and decision support systems using the geographic information system. One of the most widely used tools for digital rainfall mapping is the PRISM (parameter-elevation regressions on independent slopes model) which uses point data (rain gauge stations), a digital elevation model (DEM), and other spatial datasets to generate repeatable estimates of monthly and annual precipitation. In the PRISM, rain gauge stations are assigned with weights that account for other climatically important factors besides elevation, and aspects and the topographic exposure are simulated by dividing the terrain into topographic facets. The size of facet or grid cell resolution is determined by the density of rain gauge stations and a $5{\times}5km$ grid cell is considered as the lowest limit under the situation in Korea. The PRISM algorithms using a 270m DEM for South Korea were implemented in a script language environment (Python) and relevant weights for each 270m grid cell were derived from the monthly data from 432 official rain gauge stations. Weighted monthly precipitation data from at least 5 nearby stations for each grid cell were regressed to the elevation and the selected linear regression equations with the 270m DEM were used to generate a digital precipitation map of South Korea at 270m resolution. Among 1.25 million grid cells, precipitation estimates at 166 cells, where the measurements were made by the Korea Water Corporation rain gauge network, were extracted and the monthly estimation errors were evaluated. An average of 10% reduction in the root mean square error (RMSE) was found for any months with more than 100mm monthly precipitation compared to the RMSE associated with the original 5km PRISM estimates. This modified PRISM may be used for rainfall mapping in rainy season (May to September) at much higher spatial resolution than the original PRISM without losing the data accuracy.

• Journal of Navigation and Port Research
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• v.37 no.1
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• pp.71-77
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• 2013

Most of the maritime accidents are the crash that occurred by complex coastal terrain, increased maritime traffic and frequent weather changes. Therefore, transportation safety is exactly determined using accurate environmental informations, but if informations are inaccurate or insufficient, accident risk can be increased. Therefore, ship need the system that can accurately generate transportation safety information. This paper proposes the transportation safety system and performance evaluation in the real environment. The proposed system includes database of environment informations and navigation algorithm using PPP method to estimate the accurate ship position. Therefore, this system can accurately calculate distance or freeboard between ship with other factors. Futhermore, when weather is deteriorated, crew can sail with database based 3-D monitoring module in the transportation safety system. To verify the function and performance, data of Kyungin ARA waterway and ferry is used to evaluation.