• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.367-373
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• 2010

When the numerical analysis is carried out, it is necessary to set proper elements as a feature of analysis domains for more accurate simulations. In this study, Distinct Element Method(DEM) is applied, only considering repulsive force and tensile force except for frictional force and resisting force of particle. When the filled particles with initial Quad-tree type is relocated by DEM, a blank space existing among the particles can be minimized because the shape of particle is circular. Finally, it is the effective feature that the centroidal disposion of the particles is similar to an equilateral triangle. Triangular mesh are formed by using the Delaunay triangular technique on these relocated particles, the quality of triangular mesh is more improved by carrying out Laplace interpolations. The compared result of Aspect Ratio before and after the Laplace interpolation is shown that although the quality of triangular mesh made by DEM is good, the later triangular mesh are higher quality than the formers. In this study, although the developed technique takes a longer calculational time than the previous technique to generate triangular mesh, it is considered that the applicable possibility is very high in the generation of finite element mesh about wave analysis and various numerical simulation to need a complex or reappearance of exact topography.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.1
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• pp.11-19
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• 2018

Changgyeonggung Palace, which was built in Seongjong Period in September 1484, is a tradition space that has been seen as a gateway to the Joseon Dynasty until it was demolished in 1907 at Changgyeongwon Garden. During the Japanese colonial rule, large greenhouses, museums, and botanical gardens were opened in Changgyeonggung Palace and traditional architecture and palace gardens were lost or changed. In 1984, the Changgyeonggung Palace maintenance plan was restored to the current status through the construction of the rebuild construction in 1986 to restore the traditional palaces. Since then, it has been maintained and managed in the shape of the mid-term plan of the 1980s for 30 years. The appearance of Changgyeonggung Palace(宮園) in the early 19th century shows the appearance of Changgyeonggung Palace in "Donggwoldo", and it is possible to confirm the prototype of the Joseon Dynasty through analysis of "Donggwoldo". The vegetation survey of Changgyeonggung Palace which started from 1984 was surveyed 4 times over 2005, 2010, and 2016, and the vegetation status of Changgyeonggung Palace could be confirmed based on the results of vegetation survey. By comparing and analyzing the results of the vegetation survey for 30 years and the analysis of the vegetation in Changgyeonggung Palace by the analysis of "Donggwoldo", we were able to confirm whether the vegetation status of Changgyeonggung Palace approached to the appearance of the Joseon Dynasty era.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.159-169
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• 2012

Seokgasan(石假山) is originated in Goryeo, is a Korean traditional technique handed down to Joseon and Seokgasan is the Korean creative culture of gardening by artificial stones, which replicates small artificial mountain of natural landscape in the garden. The object of this study is Seokgasan made by Seong-im(成任), who was a civil minister in Joseon and lived from 1421 to 1484, in his residence located in Inwang Mountain, Hanyang and the purpose of this study is to investigate the historical meaning and symbol of Seokgasan made by Seong-im on the base of the relative old literatures and embody its shape and structure. According to the result of this study on Seokgasan of Seong-im, it can find out some facts as follows; Seokgasan of Seong-im in the early Joseon succeeded to the structural form of Seokgasan of the artificial rock mountain type connected pond, which was made-up firstly in the garden of the Palace of Manwoldae in the Middle Goryeo, and it was called firstly as 'Seokgasan' in the garden of Seong-im's house. Seong-im's Seokgasan in the early Joseon had more concentrated philosophical meanings, including the idea of taoist immortal, than those in the Goryeo dynasty and was be emblematic of an imaginative space. Also there were lots of gardens modeled on the famous mountains and famous lakes in China much the same as the Goryeo dynasty. In addition, there was an exceptional purpose for building Seokgasan which could not be found in the Goryeo dynasty. That was practicality for emotional stability and cure. Seong-im's Seokgasan is record-relics with high value of landscape architecture history, which can identify its historical meanings, shapes and structural frames succeeded from the Goryeo dynasty.

• Tunnel and Underground Space
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• v.22 no.4
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• pp.227-242
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• 2012

Youngju multipurpose dam is planned to minimizing the damage by flood and obtaining the water for industrial use in Nakdong river region. Faults in rock mass have strong influences on the behaviors of dam structure. Thus, it is very important to analyse for the characteristics of fault rocks in dam design. However, due to the limitation of geotechnical investigation in design stages, engineers have to carry out the additional geological survey including directional boring to find the distribution of faults and the engineering properties of faults for stability of dam. Especially, the selection of location of dam and type of dam considering fault zone must be analyzed through various experimental and numerical analysis. In this study, various geological survey and field tests were carried out to analyse the characteristics of the large fault zone through the complex dam is designed in foundation region. Also, the distribution of structural geology, the shape of faults and the mechanical properties of fault rock were studied for the reasonable design of the location and type of dam for long-term stability of the complex dam.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.109-141
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• 1992

University library must have a substantial collection development policy, by which the short and long term plannings are set up to meet the goals of university education and to support university function. Only when university library organizes collection building based on the well-planned policy, can it establish the systematic collection building, which can satisfy users, support continuity of work, use budget efficiently, and solve the space problem by with-drawing the materials. But most Korean university libraries, contrary to many foreign cases, don't have proper systematic collection development policy or guideline that controls overall library work from planning the collection of materials to evaluating and preserving them. Questionaire on whether university library has collection development policy or guideline was answered positively by only 6 cases out of 57 cases, which is just 10.5 percent. Even in cases that they have a guideline, the content of the copied guideline they sent was confined to acquisition, which is just a part of collection development. Collection development is a statement needed to set up long and short term plannings in consideration of the aims of the library and the needs of users and to shape and manage the library collection systematically. With the above conception and definition, we try to make a proper collection development policy and guideline for the Korean university libraries. Here we must define the object of the university. Object of university is to have good curriculum, good courses, research activities on the part of the faculty, enlargement of graduate school, and establishment of various institutes, etc. And in guideline, selector, method of selection, level of selection and arrangement of budget, etc. must be described concretely in its contents. Since collection development policy and guideline of Korean university libraries should concern their situation, we must confer with the result of the survey and analysis on the matter of collection determination. Here the contents include the priority of materials to be collected, method of collecting materials, arrangement of budget, and others. The purpose of this study is to develop a tenative collection development guideline in reference to the Jeonju University Library by means of analyzing the guiding principle, contents of the guideline, and present conditions of the Korean university libraries. The systematic collection development based on the Guideline for Collection Development of the Korean University Library, can offer a satisfactory service to the users of the university community, and also contribute to the development of the university itself as well as the university library.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.327-336
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• 2007

The 3D building modeling is one of crucial components in building 3D geospatial information. The existing methods for 3D building modeling depend mainly on manual photogrammetric processes by stereoplotter compiler, which indeed take great amount of time and efforts. In addition, some automatic methods that were proposed in research papers and experimental trials have limitations of describing the details of buildings with lack of geometric accuracy. It is essential in automatic fashion that the boundary and shape of buildings should be drawn effortlessly by a sophisticated algorithm. In recent years, airborne LiDAR data representing earth surface in 3D has been utilized in many different fields. However, it is still in technical difficulties for clean and correct boundary extraction without human intervention. The usage of airborne LiDAR data will be much feasible to reconstruct the roof tops of buildings whose boundary lines could be taken out from existing digital maps. The paper proposed a method to reconstruct the roof tops of buildings using airborne LiDAR data with building boundary lines from digital map. The primary process is to perform octree-based segmentation to airborne LiDAR data recursively in 3D space till there are no more airborne LiDAR points to be segmented. Once the octree-based segmentation has been completed, each segmented patch is thereafter merged based on geometric spatial characteristics. The experimental results showed that the proposed method were capable of extracting various building roof components such as plane, gable, polyhedric and curved surface.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.259-266
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• 2003

Non-rigid registration between different modality images with shape deformation can be used to diagnosis and study for inter-patient image registration, longitudinal intra-patient registration, and registration between a patient image and an atlas image. This paper proposes a hierarchical registration method using bodily tissue based segmentation for registration between color images and CT images of the Visible Human leg areas. The cross-sectional color images and the axial CT images are segmented into three distinctive bodily tissue regions, respectively: fat, muscle, and bone. Each region is separately registered hierarchically. Bounding boxes containing bodily tissue regions in different modalities are initially registered. Then, boundaries of the regions are globally registered within range of searching space. Local boundary segments of the regions are further registered for non-rigid registration of the sampled boundary points. Non-rigid registration parameters for the un-sampled points are interpolated linearly. Such hierarchical approach enables the method to register images efficiently. Moreover, registration of visibly distinct bodily tissue regions provides accurate and robust result in region boundaries and inside the regions.

• Tunnel and Underground Space
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• v.29 no.5
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• pp.332-345
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• 2019

Maximum dip vector of individual joint plane, which can be uniquely defined on the hemispherical projection plane, has been established by considering its dip and dip direction. A new stereographic projection method for the rock slope analysis which employs the maximum dip vector can intuitively predict the failure modes of rock slope. Since the maximum dip vector is uniquely projected on the maximum dip point of the great circle, the sliding direction of discontinuity plane can be recognized directly. By utilizing the maximum dip vector of discontinuity both the plane sliding and toppling directions of corresponding blocks can be discerned intuitively. Especially, by allocating the area of high dip maximum dip vector which can form the flanks of sliding block the potentiality for the formation of virtual sliding block has been estimated. Also, the potentiality of forming the triangular-sectioned sliding block has been determined by considering the dip angle of joint plane the dip direction of which is nearly opposite to that of the slope face. Safety factors of the different-shaped blocks of triangular section has been estimated and compared to the safety factor of the most hazardous block of rectangular section. For the wedge analysis the direction of crossline of two intersecting joint planes, which has same attribute of the maximum dip vector, is used so that wedge failures zone can be superimposed on the stereographic projection surface in which plane and toppling failure areas are already lineated. In addition the maximum dip vector zone of wedge top face has been delineated to extract the wedge top face-forming joint planes the orientation of which provides the vital information for the analysis of mechanical behavior of wedge block.

• Tunnel and Underground Space
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• v.29 no.5
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• pp.346-355
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• 2019

When evaluating pillar stability in very closely spaced tunnels, a local safety factor (strength/stress ratio) at the minimum width has been widely used. Tension bolts have been frequently applied as reinforcement for the cases where safety factors are less than 1.0 from FEM stress analysis. However, the local safety factor shows a constant value irrespective of the change in pillar width/tunnel diameter (PW/D) and the safety factor of the pillar is underestimated because the variation of deviation stress is relatively small even when the pre-stressing is applied to the tension bolt. In addition, the average safety factor proposed by Hoek and Brown(1980) was reviewed, but the pillar safety factor was relatively overestimated when the width of the pillar was increased. As an alternative, the SRM safety factor using shear strength reduction method shows the effect of changing the safety factor in the case of no reinforcement and tension bolt reinforcement as the pillar width/tunnel diameter(PW/D) changes. The failure shape is also similar to the previous limit theory result. In this study, the safety factor was evaluated without considering rock bolt and shotcrete to distinguish reinforcing effect of tension bolt.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.27-35
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• 2019

The existing middle-long span railway bridge has been mainly applied to steel box girder bridges. However, the steel box girder bridges have disadvantages in securing the space under the bridge, and the main girder is made of a thin plate box shape, resulting in a ringing noise due to the vibration. Many complaints about noise have been raised. For this reason, there is a need for the development of long railway bridges that can replace steel box girder bridges. In this paper, the characteristics of the steel composite railway bridge currently developed were introduced and a time history analysis was conducted using MIDAS Civil reflecting the speed of KTX load for 40m and 50m bridges. In addition, from the analysis results, the dynamic behavior of target bridges were verified and it was examined whether they meet the dynamic performance criteria proposed in the railway design standards. As a result, all of the bridges under review satisfied the dynamic safety criteria, however, in case of 40m of span, the vertical acceleration value was very large. In order to solve this problem, authors proposed the improvement plan and corrected the cross section to confirm that the vertical acceleration decreased.