• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.215-229
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• 2020

In response to the recent 4th industrial revolution, the demand for 3D object models in the latest fields of digital twin, autonomous driving, and VR/AR, as well as the existing fields such as city, construction, transportation, and energy has increased significantly. It is expected that the demand for 3D object models with various precision from LOD1 to LOD4 will increase more and more in various industry fields. However, the Ministry of Land, Infrastructure and Transport, and the local government and the private sector have partially built 3D object models of different precisions for some specific regions because of the huge cost. Therefore, this study proposes a feasible plan that can solve the cost problem in generating 3D object models for the whole territory. For our purpose, we first analyzed usage, demand, generation technology and generation cost for 3D object models. Afterwards, we proposed LOD3 model generation plan for all territory using automatic 3D object model generation technology based on image matching. Additionally, we supplemented the proposed plan by using LOD4 generation plan for landmarks and LOD2 generation plan non-urban area. In the near future, we expect this would be a great help in establishing a feasible and effective 3D object model generation plan for the whole country.

• Journal of the Korean Geotechnical Society
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• v.31 no.12
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• pp.71-76
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• 2015

Recently, people are increasingly interested in horizontal directional drilling (HDD) to construct oil and gas pipeline and utility pipeline in the urban area as one of trenchless methods. One of major issues during the HDD is the collapse of borehole, which may be the potential causes of ground collapse. This study investigated the effect of mud pressure on the borehole stability, using finite element analysis. Since the borehole is being drilled with a certain angle, three dimensional analysis should be performed. The borehole stability was examined by applying two different types of mud pressures, i.e., uniform and non-uniform, to the exterior surface of borehole. The results show that the high mud pressure at the beginning of drilling, i.e., at shallow depth, causes the borehole collapse, whereas the borehole was stable even at high mud pressure as the drilling depth increases. It can be said that the determination of maximum mud pressure is strongly related to the drilling depth.

• Journal of the Korean Geotechnical Society
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• v.36 no.7
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• pp.5-14
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• 2020

Kansai International Airport (KIX) was opened in September 1994. Although 26 years have passed since the completion of the first island, long-term settlement is still in progress. This settlement occurs in the Pleistocene layer. For it is not easy to determine the permeability of the Pleistocene sand layer because the thickness and the degree of fine content in the horizontal direction are constantly changing. In addition, it is also a difficult to predict the interactive behavior of the ground due to the construction of the second phase island adjacent to it. In order to solve this problem, a two-dimensional finite element analysis considering elasto-viscoplastic was performed to evaluate the long-term deformation, including the interactive behavior of the alternating Pleistocene foundation due to the construction of two adjacent reclaimed islands. In general, two-dimensional analysis can be used when a section can represent the entire sections. However, Kansai Airport is an artificial reclaimed island so two-dimensional analysis cannot solve the problem such as the stress deformation in the corners of the island. Additionally, the structure of the actual sub-ground through physical exploration is non-homogeneity and its thickness is also not constant. Therefore, there are limitations for the two-dimensional analysis to explain the phenomena. That is, three-dimensional analysis is strongly required. Due to these demands, the author extended the existing two-dimensional program capable of elasto-viscoplastic analysis to three-dimensional and completed the verification of the three-dimensional program developed through one-dimensional consolidation analysis. In order to demonstrate the validity of the developed 3D program that has been verified, an analysis is performed under the same analysis conditions as the existing research using a two-dimensional program. The effectiveness of the developed 3D numerical analysis program was demonstrated by comparing the analysis results with the 2D results and actual measurement data.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.4
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• pp.1-22
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• 1997

This paper was focused on the efficient management of landscape woody plants, and concerned itself with their important role in the urban environment. Based on the philosophy that there is nothing that can be done without an inventory, the purpose of this study was to develop an inventory system and iris proper application to a site for establishing a management plan Two different approaches were used, The first was to make a newly structured inventory system through collecting, analyzing, and evaluating various types of inventories used in Korea, the U. S. A., and Japan. The second approach was to apply a newly designed inventory system to the case study area. using GIS 'as a tool of spacial analysis and statistics for making decisions. The results could be summarized as follows; 1. In Korea, most of the Landscape Woozy Plants Inventories had datas which represented possession of trees, and only the work which they had done according to their traditional ways, There was no data related to the conditions, management needs, and site conditions of individual trees, This is essential information for organizing an inventory system . 2. There needs to be data which is balanced, containing tree characteristics and site characteristics. Through such information the management needs could be adjusted properly. The inventory list described in this paper was determined by botanical identity, placement condition, condition of tree, and types of work for maintaining as well as improving the condition of each tree One of the most important things was to determine the location data of each tree so as to compare data with other trees. The data gained from the field survey still had some problems because of lack of scientific method for supporting objective views, and because of actual situations, especially in the field of evaluating site conditions and management needs. All data should be revised to fit a computer data management system , if possible 3. The GIS(Geographic Information System) application showed good performance in handling inventory data for decision making. All the data used for the GIS application was divided into location and non-spatial data. Using the location data, it was easy to find the exact location of each tree on the monitor and on the maps generated by the computer even in the actual managed trite, along with various attribute data. Therefore it could be said that the entire management plan should start from data of individual trees with their exact locations, for making concrete management goals through actual budget planning.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.1-9
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• 2017

This study investigates the environmental factors of endemic species in Korea in order to understand their ecological characteristics, and to investigate the target species of their natural habitats to find similar sites. The purpose is to restore and follow suitable growth methods for the appropriate highway facility of target species to establish a management system via monitoring. This study endeavors to restore the target species near highway facilities on the basis of monitoring data and restore sites have similar natural characteristics of the target species. After restoring the target species, a restoration strategy and management plan will be established for breeding and continuation. The restoration strategy and management plan of the target species is divided into breeding, restoring, maintaining and monitoring plans. Specially management plans include several divisions such as soil, water, non-point pollution source reduction and naturalized plants. The results of this study can be used as reference materials for the restoration of endemic Korean plants in the future of highway routes, and for systematic management measures in habitats.

• Land and Housing Review
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• v.11 no.1
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• pp.21-38
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• 2020

This study examined the population movement of the young generation in accordance with the characteristics of housing market focusing on the housing problem of youth issues. Targeting 64 local governments in the seoul metropolitan area, the temporal range was decided as 2015. Setting up the rising population in 19-34 as a dependent variable, supposing that each age group shows different characteristics, it was divided into age groups in 19~34, 19~29, and 25~34. The population movement of the young generation in accordance with the characteristics of housing market was considered through the multiple regression analysis. In the results, the population movement of the young generation was influenced by the change in detached multi-family housing and the rate of housing supply. The increase of detached multi-family housing promoted the population inflow of the young generation while the population movement of the young generation was disturbed by the rising rate of housing supply. Also, when the local characteristics are not controlled, the young generation hesitates to enter the region where relatively high rent should be paid while the new housing supply focusing on apartment is hard to be selected by the young generation for residence because of the size and price. The population movement of the young generation looked quite different in each age group. The population inflow of the young generation in 19~29 was influenced when there were many officetels and non-apartments on top of detached multi-family housing. On the contrary, the population movement of the young generation in 25~34 was significantly influenced by the increase of the whole size of completed apartment area. Even though it was not the research subject of this study, among control variables, the financial independence and daily average number of get-on/off had effects on the movement of the young generation. It means that the housing type preferred by college students and social novices is different from the housing type preferred by the group with experiences in marriage and childbirth within the same young generation. Thus, it would be necessary to divide the purposes of policies for each subject when executing the youth housing policies.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.40-49
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• 2018

Purpose: The number of patients with dyslipidemia have been increasing steadily over the past few decades in South Korea. The association between the chromium level and chronic disease has attracted considerable interest, but few studies have been conducted on the Korean population. The aim of this study was to identify the dietary and non-dietary correlates of the toenail chromium level, and evaluate the association between the toenail chromium level and dyslipidemia. Methods: The baseline data of an ongoing prospective cohort study in Yeungnam area in South Korea were analyzed. A total of 500 participants aged 35 years or older who completed questionnaires on their demographics, lifestyle characteristics, and medical information were included. The toenail chromium level was analyzed by neutron activation analysis. The dietary intake was assessed using a validated 146-item semi-quantitative food frequency questionnaire. The blood lipid profiles were obtained from medical examinations conducted by the Korean National Health Insurance Service or medical institutions. Results: Higher chromium levels were associated with the residential area (urban), higher education level, higher intakes of noodles and vegetables, and lower intake of fruits. Multiple logistic regression analysis showed that the toenail chromium levels were not associated significantly with the prevalence of dyslipidemia (odds ratio: 0.99, 95% confidence interval: 0.61 ~ 1.60). Conclusion: This study is the first study in Korea to determine the independent correlates of the toenail chromium levels and the association between chromium exposure and dyslipidemia. These findings provide useful scientific evidence for the development of chromium intake guidelines for the Korean population.

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.3-9
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• 2018

Although Life Cycle Cost (LCC) must be evaluated by experts, sometimes it may not allow a sufficient time for even the experienced LCC expert to make rational decisions. Therefore, it often ends with relatively comparing the final numbers. We have broken down 110 technical proposals that are actually bade and accepted for large construction projects, and then have analyzed the uncertainty of Maintenance and Energy (M&E) cost during building life cycle, which turns out be the most volatile factor in uncertainty of LCC. Also we suggest "Value Engineering Index (VEI)" - the reduced M&E cost that is normalized by the reduced first cost. It is analyzed that the most uncertain factors of the M&E cost include repair and replacement term differing from each project, duplicated repair and replacement, non-standard repair items, and site-specific energy cost. Eventually we propose a VEI population with a mean of 1.38 and a standard deviation of 1.19, which is obtained by individually and exclusively applying the uncertain factors of the M&E cost to the 35 standard sample of technical proposals. The LCC evaluators may be able to use the VEI population as the benchmark to select the technical proposal with the most reasonable LCC among many others in two suggested manners; the one is to deterministically calculate the probability of single VEIs, and the other is to stochastically calculate the probability of the VEIs where uncertainty is quantified.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.87-92
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• 2011

This paper describes a study on the permeability reduction of the riverbed ground during urban railway tunnel construction. The research is mainly concentrated on the study of the grouting or injection methods among permeability reduction methods which can be adapted in the riverbed ground. The design technology of grouting methods considering the long term hydro-geological behaviour in the riverbed, was suggested. Two injection methods namely, Natural Durable Stabilizer (N.D.S) and Space-Multi Injection Grouting (S.M.I) methods, were introduced as new approach methods which could be adapted to modify the riverbed ground. In order to evaluate the performance of the improved ground by the N.D.S and S.M.I method, a series of pilot tests including the field and laboratory permeability tests, were carried out in the river crossing tunnel construction sites. The results obtained from pilot test program, were also reviewed. The results, the grouting efficiency of the S.M.I method using the non-alkalimeter silica sol is better than that of N.D.S method using cement. In addition, it is anticipated that the current research results are contributed to develop the grouting design technology.

• Journal of Preventive Medicine and Public Health
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• v.52 no.2
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• pp.131-139
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• 2019

Objectives: Self-reporting can be used to determine the incidence and prevalence of hypertension (HTN). The present study was conducted to determine the validity of self-reported HTN and to identify factors affecting discordance between self-reported and objectively measured HTN in participants in the Ravansar Non-Communicable Diseases (RaNCD) cohort. Methods: The RaNCD cohort included permanent residents of Ravansar, Iran aged 35-65 years. Self-reported data were collected before clinical examinations were conducted by well-trained staff members. The gold standard for HTN was anti-hypertensive medication use and blood pressure measurements. The sensitivity, specificity, positive and negative predictive values, and overall accuracy of self-reporting were calculated. Univariate and multivariate logistic regression were used to examine the discordance between self-reported HTN and the gold standard. Results: Of the 10 065 participants in the RaNCD, 4755 (47.4%) were male. The prevalence of HTN was 16.8% based on self-reporting and 15.7% based on medical history and HTN measurements. Of the participants with HTN, 297 (18.8%) had no knowledge of their disease, and 313 (19.9%) had not properly controlled their HTN despite receiving treatment. The sensitivity, specificity, and kappa for self-reported HTN were 75.5%, 96.4%, and 73.4%, respectively. False positives became more likely with age, body mass index (BMI), low socioeconomic status, and female sex, whereas false negatives became more likely with age, BMI, high socioeconomic status, smoking, and urban residency. Conclusions: The sensitivity and specificity of self-reported HTN were acceptable, suggesting that this method can be used for public health initiatives in the absence of countrywide HTN control and detection programs.