• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.2
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• pp.201-208
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• 2006

Currently, 1/5,000 Digital Topographic Map covers the whole country with administrative boundary of Gu, while some region has already been constructed with 1/1,000 digital topographic map has legal boundary of Dong. Here, Dong in 1/1,000 scale represents the legal boundary which is used in the address most of time. Therefore, there is no administrative-Dong yet although it is very useful in various fields. In this study, we suggested a method to construct the administrative boundary extending to the level of Dong empirically. In addition, the practical application of the administrative boundary in GIS is discussed. Two methods are applied to construct the administrative boundary to the level of administration-Dong; using the edited cadastral map and the digital topographic map. When the edited cadastral map is used, some problems such as boundary discordance to superordinate administrative area is appeared. On the other hand, using digital topographic map showed simple construction processes and easy connection with other framework data. Therefore, it is recommended that the digital topographic map should be used in the construction of the administrative boundary. It would be useful as framework data in various industries and public operations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.417-424
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• 2006

Despite of many researches related to create 3D digital maps, it is still time-consuming and costly because a large part of 3D digital mapping is conducted manually. To circumvent this limitation, we proposed methodologies to create 3D digital maps with 3D symbols automatically. For this purpose, firstly, the 3D symbol library to represent 3D objects as 3D symbols was constructed. In this library, we stored the attribute and geometry information of 3D objects which define types and shapes of symbols respectively. These information were used to match 3D objects with 3D symbols and extracted from 2D digital maps and LiDAR(Light Detection and Ranging) data. Then, to locate 3D symbols into a base map automatically, we used predefined parameters such as the size, the height, the rotation angle and the center of gravity of 3D objects which are extracted from LiDAR data. Finally, the 3D digital map in urban area was constructed and the results were tested. Through this research, we can identify that the developed algorithms can be used as effective techniques for 3D digital mapping.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.423-431
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• 2008

The control surveying which aims at identifying the coordinate system of satellite images with that of ground is a repeatedly performed essential process to produce digital ortho - photos and it acts as the main factor to increase the production cost of the photos by duplicated budgets and redundant works when executing the projects for acquiring basic geographical information from high density satellite images. During the experimentation, an application system was established for producing a stereo image chip by the analysis of DPPDB file structure, the stereo image chip was produced with SPOT and IKONOS images, the analysis of 3D modeling accuracy was performed to secure the required accuracy and to present the optimal number and deployment of the control points, and a 3D modeling was performed for new SPOT images and lastly, 3D ground coordinates were extracted by the observation of the same points through the overlapping with the new images. As the results of the research, it is proved that the stereo image chip can be used as the ground controls through the accuracy analysis between the coordinates of the images and the ground, close results were obtained between the coordinates by the ground survey and those by the 3D modeling using new images and the observation of the same points, positional changes were not found during observing the same points, and the research presented the methodology for improving the process of the control survey by showing the availability of the image controls on the stereo image chip instead of the ground controls.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.3
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• pp.227-239
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• 2008

Processing LiDAR (Light Detection And Ranging) data obtained from ALS (Airborne Laser Scanning) systems mainly involves organization and segmentation of the data for 3D object modeling and mapping purposes. The ALS systems are viable and becoming more mature technology in various applications. ALS technology requires complex integration of optics, opto-mechanics and electronics in the multi-sensor components, Le. data captured from GPS, INS and laser scanner. In this study, digital image processing techniques mainly were implemented to gray level coded image of the LiDAR data for building extraction and superstructures segmentation. One of the advantages to use gray level image is easy to apply various existing digital image processing algorithms. Gridding and quantization of the raw LiDAR data into limited gray level might introduce smoothing effect and loss of the detail information. However, smoothed surface data that are more suitable for surface patch segmentation and modeling could be obtained by the quantization of the height values. The building boundaries were precisely extracted by the robust edge detection operator and regularized with shape constraints. As for segmentation of the roof structures, basically region growing based and gap filling segmentation methods were implemented. The results present that various image processing methods are applicable to extract buildings and to segment surface patches of the superstructures on the roofs. Finally, conceptual methodology for extracting characteristic information to reconstruct roof shapes was proposed. Statistical and geometric properties were utilized to segment and model superstructures. The simulation results show that segmentation of the roof surface patches and modeling were possible with the proposed method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.4
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• pp.421-428
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• 2009

In Korea, the change of river flux due to seasons change is so considerable because of the mountainous terrain with the sharp slope and leaned rainfall. This unfavorable natural condition and the difficulties in precise grasping of the river status made the water resource management difficult so that the necessity of the precise river management has been continuously increased. In this study, a precise river-region DEM using the latest equipments of ALS and MBES is constructed. After acquiring DEM from each senor on the river region, a single DEM was generated by combining them. Also, the field inspection was carried out in the overlapped region of ALS and MBES in order to verify the quality of DEM. The verification of DEM was carried out by comparison between TINs obtained from the combined result of ALS and MBES and the surveying result from total station at more than 10 points in the selected two test areas. As a result, NO.1-area's RMSE of 0.322m and 0.113m are obtained for NO. 1 and NO. 2 areas, respectively. The result of this study shows the feasibility of DEM construction for river region using ALS and MBES as seen in the case of NO. 2 area. At the same time, it was appeared that a better method on the data fusion should be developed as seen in the result of NO. 1 area.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.304-311
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• 2013

There have been increasing cases for farmers to install automated weather stations (AWS) at their farms and orchards in order to take countermeasures to more frequent weather disasters caused by climate variability and weather extremes. Although raw data are the same, the additive values as agrometeorological information may vary depending on data processing methods. User demands on appropriate information could also be different among crop species, cropping systems and even cultivars. We designed an internet based AWS data processing and display system to help diverse users (e.g., farmers), extension workers to access their weather data on specific demands. The system was implemented at a rural catchment with 52 $km^2$ land area where 14 automated weather stations are in operation. This note introduces the system and describes the major modules in detail. By linking regional AWS networks, a feasibility for this system as an early warning system is also discussed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.219-233
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• 2013

We employed the ecological niche modeling framework using GARP (Genetic Algorithm for Ruleset Production) to model the current and future geographic distribution of Pinus densiflora based on environmental predictor variable datasets such as climate data including the RCP 8.5 emission climate change scenario, geographic and topographic characteristics, soil and geological properties, and MODIS enhanced vegetation index (EVI) at 4 $km^2$ resolution. National Forest Inventory (NFI) derived occurrence and abundance records from about 4,000 survey sites across the whole country were used for response variables. The current and future potential geographic distribution of Pinus densiflora, one of the tree species dominating the present Korean forest was modeled and mapped. Future models under RCP 8.5 scenarios for Pinus densiflora suggest large areas predicted under current climate conditions may be contracted by 2090 showing range shifts northward and to higher altitudes. Area Under Curve (AUC) values of the modeled result was 0.67. Overall, the results of this study were successful in showing the current distribution of major tree species and projecting their future changes. However, there are still many possible limitations and uncertainties arising from the select of the presence-absence data and the environmental predictor variables for model input. Nevertheless, ecological niche modeling can be a useful tool for exploring and mapping the potential response of the tree species to climate change. The final models in this study may be used to identify potential distribution of the tree species based on the future climate scenarios, which can help forest managers to decide where to allocate effort in the management of forest ecosystem under climate change in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.377-383
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• 2000

The composition of primary minerals of sand fractions and secondary minerals of clay fractions were investigated on the polder soils developed from alluvio-marine deposits near to Sapgyo-lake, constructed a sea dike across river estuary located in the west coast. The effects of a topographical sequence on the physico-chemical properties and mineralogical characteristics were evaluated using XRD, DTA, and TG with the chemical composition of $H^+$ saturated clays. Soils located on the seashore side were more silt fraction, higher pH and exchangeable cations than the others. The dominant minerals of soil parent materials are in the order of quartz, feldspars, micas, chlorite and amphibole. According to the greater distance from the lake, the amount of 1:1 minerals increased, but 2:1 minerals decreased. The dominant clay minerals of polder soils are kaolinite, vermiculite and illite. Hydroxy interlayer minerals are abundant in the clay fractions derived from the soil parent materials which have relatively low soil pH.

• Journal of Sericultural and Entomological Science
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• no.12
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• pp.13-16
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• 1970

The studies were intended to clarify the correlations between the characters and the influences upon yield of mulberry trees. The analysis of covariance was used to obtain the genotypic correlations and phenotypic correlations among the eight characters namely branch length, node number, branch diameter, branch number per stock, total branch weight, old branch weight, new shoot and leaf weight, etc., and path-coefficients were calculated by Dewey's method (5). The results obtained are summarized as follows： 1. Genotypic correlations were slightly higher than the corresponding phenotypic correlations between tile characters as shown in Table 1. It could be indicated that hight leaf yield was genetically correlated with almost all characters studied except branch diameter. 2. Leaf yield of mulberry trees was mainly associated with the characters such as node number per branch, total branch weight and old branch weight, etc. 3. Branch length, branch diameter, branch number per stock and new shoot weight had little direct influence upon yield but it had rather considerable indirect in fluence upon yield by increasing the node number and total branch weight per stock. As a result, it can be concluded that total branch weight is primarily determined by branch number per stock and old branch weight, and in turn the leaf yield of mulberry trees is secondary determined by the node number by increasing the branch diameter and length which are positively correlated with branch number per stock and new shoot weight of mulberry trees.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.345-356
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• 2012

We conducted a survey of actual using conditions of farm-made liquid fertilizers by investigating their formulation types, materials, making processes, using methods and various beneficial effects on 29 farms certified by National Agricultural Products Quality Management Service to produce environment-friendly agricultural products in 2009. Most of the materials used to make liquid fertilizers are those that can be easily obtained around the farms. Molasses or black sugar are added as an energy source of microorganism. And leaf mold, bacterial cultures supplied by agricultural extension centers of local governments, and cultures of native microorganisms were used as microbial sources for fermenting effective microorganisms. Types of the farm-made liquid fertilizers were fermented liquid fertilizers, fermented plant juices, amino acid liquid fertilizers, calcium-liquid fertilizers, and phosphoric acid liquid fertilizers. Effects of liquid fertilizers used by the farms were found to promote plant growth by supplying nutrition, to accelerate blooming and flower bud formation, to enhance the quality of agricultural products such as increase of sugar contents and improvement of storing conditions, to induce resistance against diseases and insect pests, and to cause endurance to high temperature stress. Chemical properties of the liquid fertilizers collected were analyzed. As a result, pH and EC range showed differences according to kinds of the liquid fertilizers. Amount of macro-nutrients, such as nitrogen and phosphoric acid, in most of the collected liquid fertilizers, was found to be low. Even though the liquid fertilizers were made from same materials, their contents was found to be different depending on the making process.