• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.54-67
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• 2023

Mount Tai, with an elevation of 1,532 meters, has a reputation as ''The Most Revered of the Five Sacred Mountains (五嶽獨尊)", despite not being the highest mountain in China. A guidebook is a book or pamphlet that contains an introduction and description of specific activities or facilities, especially detailed and accurate information about scenic spots, which provide superior vistas to than other commercially publicized locations. The study aims to investigate Mount Tai's landscape characteristics by analyzing the landscape types and elements, the Kernel Density, the Mean Center and the Standard Deviational Ellipse of the landscape elements appearing in guidebooks introducing Mount Tai. The research results of this study are summarized as follows. First, the landscape type characteristics of Mount Tai are dominated by natural landscapes, which are different from what was shown highlighted in poems and Big Data as they proposed that the landscape characteristics of Mount Tai is dominated by human activities. Second, from the perspective of subdivided landscape types, the landscape elements that appeared in Mount Tai are topography, structure, architecture, plants, semantics, human beings and image orderly, based on the proportion of landscape elements. Third, from the perspective of landscape elements by times series, "Fengshan (封禅)", "sacrifices (祭祀)" and "legends" mostly appeared in the 1950s and 1980s, and after the 1990s, "climbing" and "overlooking" mostly appeared. Fourth, the landscape elements of Mount Tai are concentrated in Daiding (岱顶) and Dai Temple (岱庙) in all periods in terms of spatial distribution. This will become an important space for Mount Tai scenic spots in the future. Moreover, as a whole, the landscape elements of Mount Tai have changed from the concentrated distribution form in Mount Tai scenic spot to the scattered distribution form including Mount Tai and Tai'an City. This will provide necessary enlightenment for the landscape preservation and the re-production of guidebooks of Mount Tai scenic spot in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.1
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• pp.13-26
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• 2023

Recently, as the development of underground spaces has become active due to rapid urbanization and population density, interest in the ground behavior according to the construction of underground spaces is increasing. In large cities with high population density and many buildings, ground subsidence has a great impact on structures and there may be a risk of collapse, so the analysis of ground behavior due to underground construction is essential. Previous studies have been conducted on the subsidence pattern of the surface and the deformation of the tunnel when constructing the tunnel, but analysis has rarely been conducted by using actual topographic information. Therefore, this study analyzed the difference in ground behavior between the actual topography and the flat topography. As a result, it was confirmed that ground settlement occurs at higher elevations, such as in mountainous topography, and when the numerical analysis is performed considering topographical information, the crown settlement of the tunnel is up to about approx. It showed a difference of 10 mm, and it was found that the sensitivity was less in the case of displacement of tunnel wall compared to the crown settlement and ground settlement. The numerical analysis considering the actual GIS-based topographic information presented in this study can be used to obtain more accurate surface subsidence data to understand the behavior of the upper structure due to tunnel excavation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.1
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• pp.1-7
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• 2023

An artificial intelligence (AI) method based on image deep learning is proposed to predict the entire displacement shape of a structure using the feature of partial displacements. The performance of the method was investigated through a structural test of a steel frame. An image-to-image regression (I2IR) training method was developed based on the U-Net layer for image recognition. In the I2IR method, the U-Net is modified to generate images of entire displacement shapes when images of partial displacement shapes of structures are input to the AI network. Furthermore, the training of displacements combined with the location feature was developed so that nodal displacement values with corresponding nodal coordinates could be used in AI training. The proposed training methods can consider correlations between nodal displacements in 3D space, and the accuracy of displacement predictions is improved compared with artificial neural network training methods. Displacements of the steel frame were predicted during the structural tests using the proposed methods and compared with 3D scanning data of displacement shapes. The results show that the proposed AI prediction properly follows the measured displacements using 3D scanning.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.662-675
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• 2022

This study was intended to investigate and analyze the current status of the plant community structure in order to provide basic data for the systematic conservation and management of the Buxus sinica area appearing on the ridgeline connecting the Gyeokjabong(Mt.) and Keungiljae, on Bogildo Island. In consideration of location characteristics such as density, topography, and direction of B. sinica appearing in the shrub layers, a total of 26 sites were set as the survey area for representative vegetation communities or areas with changes in topography. According to DCA and TWINSPAN, it was classified into 6 communities, namely Carpinus turczaninovii-Deciduous broad-leaved, C. turczaninovii, C. turczaninovii-B. sinica, C. turczaninovii-Evergreen broad-leaved, Q. acuta, and D. trifidus-Q. acuta. The community dominated by C. turczaninovii maintains the status quo for the present moment, however, Q. acuta will dominate the surrounding area in the long term, so Q. acuta has high succesion potential. In the case of the Q. acuta and D. trifidus-Q. acuta communities, Q. acuta, known as the climax species of warm-temperate forests, will maintain dominant status. In a case of B. sinica, the community dominated by C. turczaninovii will remain in good status due to the topographical conditions, but the community dominated by Q. acuta growth difficulties are expected due to the high coverage. In the relationship between environmental factors and vegetation distribution, analysis showed that only soil pH affect vegetation distribution. Furthermore, the soil acidity (pH) was 3.78-5.30, the electrical conductivity was 0.186-0.543 dS/m, and the organic matter content was 2.25-2.89%.

• Journal of the Korean Geotechnical Society
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• v.23 no.2
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• pp.47-60
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• 2007

Conventional active surface wave measurements performed using a transient or continuous source are often limited in the maximum depth of penetration due to the difficulty of generating low-frequency energy with reasonably portable sources. This limitation may inhibit accurate seismic site response calculations because of the inability to define deeper subsurface structure. By measuring surface wave generated by passive sources including microtremors and cultural noise, it is possible to overcome this problem and develop soil stiffness profiles to much larger depth. Reliability of dispersion estimates from the passive surface wave measurements is critical to present reliable shear wave velocity profiles and can be improved by the measurements and analyses of passive surface waves based on correct understanding of systematic errors included in passive dispersion data. In this study, the systematic errors caused by poor wavenumber resolution and energy leakage into sidelobes in passive tests are mainly explored. Recommendations for reliable passive surface wave measurements and dispersion estimates are presented and illustrated at a site in San Jose, California, U.S.

• Journal of the Korean Geotechnical Society
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• v.23 no.12
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• pp.61-73
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• 2007

As a part of Load and Resistance Factor Design(LRFD) code development in Korea, in this paper an intensive reliability analysis was performed to evaluate reliability levels of the two static bearing capacity methods for driven steel pipe piles adopted in Korean Standards for Structure Foundations by the representative reliability methods of First Order Reliability Method(FORM) and Monte Carlo Simulation(MCS). The resistance bias factors for the two static design methods were evaluated by comparing the representative measured bearing capacities with the design values. In determination of the representative bearing capacities of driven steel pipe piles, the 58 data sets of static load tests and soil property tests were collected and analyzed. The static bearing capacity formula and the Meyerhof method using N values were applied to the calculation of the expected design bearing capacity of the piles. The two representative reliability methods(FORM, MCS) based computer programs were developed to facilitate the reliability analysis in this study. Mean Value First Order Second Moment(MVFOSM) approach that provides a simple closed-form solution and two advanced methods of FORM and MCS were used to conduct the intensive reliability analysis using the resistance bias factor statistics obtained, and the results were then compared. In addition, a parametric study was conducted to identify the sensibility and the influence of the random variables on the reliability analysis under consideration.

• Korean Journal of Plant Taxonomy
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• v.53 no.1
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• pp.32-37
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• 2023

Spiraea prunifolia f. simpliciflora Nakai is a perennial shrub widely used for horticultural and medicinal purposes. We simultaneously obtained the complete plastid genome (plastome) and nuclear ribosomal gene transcription units, 45S nuclear ribosomal DNA (nrDNA) and 5S nrDNA of S. prunifolia f. simpliciflora, using Illumina short-read data. The plastome is 155,984 bp in length with a canonical quadripartite structure consisting of 84,417 bp of a large single-copy region, 18,887 bp of a short single-copy region, and 26,340 bp of two inverted repeat regions. Overall, a total of 113 genes (79 protein-coding genes, 30 tRNAs, and four rRNAs) were annotated in the plastome. The 45S nrDNA transcription unit is 5,848 bp in length: 1,809 bp, 161 bp, and 3,397 bp for 18S, 5.8S, and 26S, respectively, and 261 bp and 220 bp for internal transcribed spacer (ITS) 1 and ITS 2 regions, respectively. The 5S nrDNA unit is 512 bp, including 121 bp of 5S rRNA and 391 bp of intergenic spacer regions. Phylogenetic analyses showed that the genus Spiraea was monophyletic and sister to the clade of Sibiraea angustata, Petrophytum caespitosum and Kelseya uniflora. Within the genus Spiraea, the sections Calospira and Spiraea were monophyletic, but the sect. Glomerati was nested within the sect. Chamaedryon. In the sect. Glomerati, S. prunifolia f. simpliciflora formed a subclade with S. media, and the subclade was sister to S. thunbergii and S. mongolica. The close relationship between S. prunifolia f. simpliciflora and S. media was also supported by the nrDNA phylogeny, indicating that the plastome and nrDNA sequences assembled in this study belong to the genus Spiraea. The newly reported complete plastome and nrDNA transcription unit sequences of S. prunifolia f. simpliciflora provide useful information for further phylogenetic and evolutionary studies of the genus Spiraea, as well as the family Rosaceae.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.43-53
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• 2009

Knowledge retrieval service that uses collective intelligence which has special quality of open structure and can share the accumulative data is gaining popularity. However, acquiring the right needs for users from massive public knowledge is getting harder. Recently, search results from Google which is known for it's exquisite algorism, shows results for collective intelligence such as Wikipedia, Yahoo Q/A at the highest rank. Objective of this paper is to show that most answers come from human and to find the most influential people in on-line knowledge retrieval service. Hereupon, this paper suggest the influence value calculation algorism by analyzing user relation as centrality which social network is based on user activeness and reliance in Naver 지식iN. The influence value calculated by the suggested algorism will be an important index in distinguishing reliable and the right user for the question by ranking users with troubleshooting solutions in the knowledge retrieval service. This will contribute in search satisfaction by acquiring the right information and knowledge for the users which is the most important objective for knowledge retrieval service.

• The Mathematical Education
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• v.61 no.1
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• pp.1-28
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• 2022

The purpose of this study is to explore how students' fractional knowledge is related to their solving of proportion problems. To this end, 28 clinical interviews with four middle-grade students, each lasting about 30~50 minutes, were carried out from May 2021 to August 2021. The present study focuses on two 7th grade students who exhibited their ability to coordinate three levels of units prior to solving whole number problems. Although the students showed interiorization of three levels of units in solving whole number problems, how they coordinated three levels of units were different in solving proportion problems depending on whether the problems required reasoning with whole numbers or fractions. The students could coordinate three levels of units prior to solving the problems involving whole numbers, they coordinated three levels of units in activity for the problems involving fractions. In particular, the ways the two students employed partitioning operations and how they coordinated quantitative unit structures were different in solving proportion problems involving improper fractions. The study contributes to the field by adding empirical data corroborating the hypotheses that students' ability to transform one three levels of units structure into another one may not only be related to their interiorization of recursive partitioning operations, but it is an important foundation for their construction of splitting operations for composite units.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.19-35
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• 2022

In this study, the forest vegetation structure in the Maruguem (ridge line) area from Yuksipryeong to Cheonwangbong, Baekdudaegan, was analyzed using vegetation classification, importance values, species diversity, and NMS. Data were collected using 373 quadrates in a Braun-Blanquet vegetation survey conducted from May to October 2020. Vegetation was classified into nine vegetation units, which were verified using DCA analysis. Vegetation units 1-5, which were grouped by sub-alpine region, showed high importance values, mainly for sub-alpine vegetation, such as Abies koreana, Picea jezoensis, Pinus koraiensis, and Betula ermanii. In Maruguem, which is not high above sea level, importance values for species such as Pinus densiflora and Quercus serrata were high due to the topographical characteristics of the ridge. The A. koreana community (vegetation unit 1-5), which had a relatively high average elevation, had higher species diversity compared with that of other vegetation units. According to NMS analysis, for abiotic environmental factors, there was a positive correlation between vegetation units 1, 2, 4, and 5 and elevation. Overall, this study describes all low-elevation area vegetation (P. densiflora and Lindera erythrocarpa) to high-elevation area vegetation (A. koreana and P. jezoensis) as well as the characteristics of the Baekdudaegan ridge vegetation that did not include valley vegetation.