• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.644-658
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• 2021

Understanding the functional traits of dominant species in urban ecosystems provides insight into species' trait adaptation and ecosystem function in response to fragmented and isolated urban vegetation and reduced biological interactions. This study compared means and variances of environmental factors (geographic, meteorological, and soil attributes) and 4 leaf traits (leaf area, specific leaf area, leaf dry mass content, and leaf shape index) and 7 reproductive traits (fruit width, fruit length, fruit shape, fruit dry weight, fruit dry matter content, seed weight, and seed ratio) measured of 40 Sorbus alnifolia individuals in four mountainous areas south of Seoul downtown, South Korea. We then performed the multivariate analysis of trait combinations. While the measured environmental factors indicated the individuality of the survey sites, the urban vegetation was drier and had a longer growth period. The leaves of S. alnifolia in the urban areas were smaller and heavier, and the fruits produced longer and lighter seeds, showing the traits affected by long urbanization. The study confirmed changes in the growth and reproduction mechanism of the S. alnifolia population under the urban environment, indicating reduced biological interaction due to vegetation fragmentation and isolation. This study provides limited but distinct ecological information about the function and persistence of key species in cities with a reduced scale of biological interactions and many negative environmental factors such as air pollution.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.159-168
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• 2022

Local governments should try to resolve the inequality of living SOC (Social Overhead Capital) and construct spatial information on the location of living SOCs and optimal locations. This study analyzed the accessibility, equity, and optimal location of the living SOC, considering the research needs related to the living SOC. The target facility is core living facilities(a public library, a park, a culture center, and a public daycare center). The analysis area is Suwon city in Gyeonggi province, and the base year of the analysis is 2020. The study calculated accessibility per population in a microscopic neighborhood living area(200m×200m). The Gini coefficient was used to identify the regional disparity in accessibility among Dong regions. The optimal location was explored with the Maximal Covering Location Problem theory. As a result, spatial accessibility of facilities except for public daycare centers revealed a large gap between regions. Areas with excellent accessibility also showed significant variations in the facilities. The regional disparity in living SOC was the largest in culture centers, followed by parks, public daycare centers, and public libraries. The optimal locations for public libraries, parks, and culture centers are concentrated in the old downtown, while those of public daycare centers are found throughout Suwon city. The results of this study are the crucial contents of spatial planning for SOC supply in local governments. Therefore, follow-up studies will be able to refer to the analysis structure and results of the study.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.93-104
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• 2021

A coastal ferries, which serve as a mode between mainland and offshore islands, are frequently used by islanders and travelers visiting islands. Therefore, it is located in a place with good accessibility to the downtown so that users can use it conveniently. However, research on the built environment and walking environment of coastal ferry terminals has not been conducted to ensure that elderly islanders and general travelers can use comfortably the coastal ferry terminal. In this study, with a focus on the coastal ferry terminal space, the walking section was set as 1)the accessibility of the coastal ferry terminal, 2)the built environment for using the coastal ferry terminal, and 3)walking environment in the ferry boarding and disembarkation at the coastal ferry terminal, and 4, 5)walking environment in the ferry. An evaluation tool was developed to measure the walking environment for each walking section, and the importance and satisfaction of users were analyzed using the IPA for the Yeosu Coastal Ferry Terminal. As a result, in the process of approaching the ferry terminal, 'convenience of using public transportation by foot' and 'convenience of using signposts guiding the location and direction of the ferry terminal' were investigated as concentrated areas. On the other hand, the built environment inside the ferry terminal and the walking environment showed that the satisfaction of the users was high. Regarding the walking environment from the ferry terminal to the ferry, the 'surface walking environment of the walking path', 'convenience of walking with luggage', 'convenience of walking in the slope section', and 'convenience of walking in the ferry ramp section' showed low satisfaction. This study can be used as basic data for improving the facilities and walking environment of Yeosu Coastal Ferry Terminal and is expected to be used as data for comparative research with other coastal ferry terminals.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.69-75
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• 2021

This study investigated the status of disaster response, focusing on modern architecture. The modern architecture is drawing more attention and being more used in the local community among the architectural heritage in downtown collective. The railway employee residence area in Soje-dong, Daejeon is a collective building group, and the efforts to evaluate and preserve its historical, cultural, and architectural values have been underway. However, the area is now an undesignated cultural property that does not receive institutional protection. It carries significance in preserving it as a collective building group. Yet, since the main structure is made of wood, the risk of being destroyed by fire or disaster is high, and disaster prevention measures are insufficient. Therefore, this study examined the structural and non-structural conditions such as the arrangement and architectural characteristics of official residence buildings, and looked into measures of the construction of a disaster prevention system and residents' participation. To preserve the urban historical environment created as a collective architectural heritage, it is necessary that the area reinforces its own disaster prevention capabilities, such as establishing an effective disaster prevention system considering village characteristics, strengthening disaster prevention capabilities based on residents' participation, and forging formal and informal governance in the local community.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.101-113
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• 2022

This study is planned with the aim of developing a systematic construction process based on the scientific and engineering theory of the water-sealing grouting construction applied to the tunnel excavation process during the construction of the downtown underground traffic network, so that the construction quality of the relatively backward domestic tunnel water-sealing grouting construction is improved and continuously maintained no matter who constructs it. The main contents of the improved tunnel water-sealing grouting can be largely examined in the classification of tunnel water-sealing grouting application and the definition of grouting materials, the correlation analysis of groundwater pressure conditions with groundwater inflow, the study of the characteristic factors of bedrock, and the element technologies and injection management techniques required for grouting construction. Looking at the trends in global research, research in the field of theoretical-based science and engineering grouting is actively progressing in Nordic countries (Sweden, Finland, Norway, etc.), Japan, Germany, and the United States. Therefore, in this study, the algorithm is established through theoretical analysis of the elements of tunnel water-sealing grouting construction techniques to provide an integrated solution including a construction process that can effectively construct tunnel water-sealing grouting construction.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.5
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• pp.1-12
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• 2022

COVID-19 led to an increased need for mountainous urban parks in the city that can be enjoyed while moving rather than staying put. However, studies on the economic value of mountainous urban parks have been insufficient. As a result, this study investigates the economic value of Gyeyangsan, a mountainous urban park located in the city, by quantifying the value of natural resources provided to residents and analyzing the factors affecting these values. The results are summarized below. First, according to the economic value assessment of Gyeyangsan, the use value was 2,210 won per person or 4.42 billion won per year, and the preservation value was 6,182 won per household, or 129.37 billion won. Gyeyangsan's total assets value was assessed as 3.68 trillion won. Second, according to the estimates of the willingness to pay and the determinants for the use-value, the frequency of visits, age, and use satisfaction significantly impacted the intention to pay for the use-value. Third, according to the estimates of the willingness to pay and the determinants for the preservation value, the intention to revisit, volunteer participation, educational level, gender, and residence significantly influenced the intention to pay for the preservation value. According to the findings of this study, it will be possible to make crucial policy implications when setting a direction for future park management by presenting a practical policy plan for the maintenance of mountain parks in downtown areas and will broaden the scope of research.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.189-200
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• 2023

As urbanization and industrialization increase development in downtown areas, damage due to ground settlement continues to occur. Building collapse in urban has a high risk of leading to large-scale damage to life and property. However, there has rarely been studied on measurement data analysis methods when uneven loads are applied to the excavated ground and no prior knowledge of the ground. Accordingly, it was attempted to analyze the relative settlement behavior and correlation by processing the time-series surface settlement of construction sites in the urban. In this paper, the average index of difference in settlement and average of relative difference in settlement are defined and calculated, then plotted in the coordinate system to analyze the relative settlement behavior over time. In addition, since there was no prior knowledge of the ground, a standard to classify the clusters was needed, and the observation points were classified into using k-means clustering and Dunn Index. As a result of the analysis, it was confirmed that all the clusters moved to the stable region as the settlement amount converges. The clusters were segmented. Based on the analysis results, it was possible to distinguish between the independent displacement area and same behavior area by analyzing the correlation between measurement points. If possible to analyze the relative settlement behavior between the stations and classify the behavior areas, it can be helpful in settlement and stability management, such as uplift of the surrounding area, prediction of ground failure area, and prevention of activity failure.

• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.87-95
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• 2023

Recently, redevelopment of the original downtown area is underway, the necessity of construction in adjacent location is increasing. However, excavations in dense urban areas are prone to ground problems due to various causes, so it is necessary to use materials and methods that can minimize such problems. As a general earth retaining method, various methods such as diaphragm wall and CIP method are applied using cement. However, since a large amount of cement is used for the installation of earth retaining method, it is necessary to conduct research on the development of new cement substitute materials to significantly reduce greenhouse gas emissions. In this study, we utilized the hardening reaction of blast furnace slag powder, desulfurized gypsum and high calcium fly ash by alkali activation and applied it to the SCW method. As a result, it was analyzed that the compressive strength of solidified soil using development solidification material was 96.2 ~ 106.3% of OPC at 28 days of curing. In addition, the strength increment ratio was 2.06 for sandy soil and 2.41 for clayey soil, which was higher than 1.85 of OPC. It seems an advantageous in terms of long-term strength. In addition, from the environmental point of view, it was analyzed that there is no elution of heavy metals and that greenhouse gas emissions can be dramatically reduced. Therefore, if further studies are conducted, it can be applied to the SCW method.

• Journal of the Korean GEO-environmental Society
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• v.24 no.4
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• pp.23-29
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• 2023

Ground subsidence shows a mechanism in which the upper ground collapses due to the formation of a cavity due to the movement of soil particles in the ground due to the formation of a waterway because of damage to the water supply/sewer pipes. As a result, cavity is created in the ground and the upper ground is collapsing. Therefore, ground subsidence frequently occurs mainly in downtown areas where a large amount of underground facilities are buried. Accordingly, research to predict the risk of ground subsidence is continuously being conducted. This study tried to present a ground subsidence risk prediction model for two districts of ○○ city. After constructing a data set and performing preprocessing, using the property data of underground facilities in the target area (year of service, pipe diameter), density of underground facilities, and ground subsidence history data. By applying the dataset to the machine learning model, it is evaluated the reliability of the selected model and the importance of the influencing factors used in predicting the ground subsidence risk derived from the model is presented.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.313-325
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• 2023

Purpose: According to the recent occurrence statistics of ground accidents, ground subsidence and subsidence have become social problems as the frequency has increased centering around the downtown areas. This study tried to clarify risk of detailed factors which have an effect on subsidence. Method: For the study, detailed risk factors of 28 foundations were mainly drawn through the materials, precedent studies, and research reports shown by analyzing JIS' accident cases from 2016 to September 6, 2022 and by taking advice from an excavation expert. And risk was assessed by conducting a survey on 12 subsidence experts from the universities, research institutes, and industries and applying Fuzzy-FMEA to it. Result: It has found that damage of sewer pipes is 24.99% of overall risk, followed by excavation work (17.34%), water pipes (14.84%), and poor compaction (refill) (13.93%). And it has found that risk of damaging utilities (water pipes, sewer pipes, and other utilities) is highest, followed by poor construction works (excavation work, damage of sewer and water pipes, and other utility work) and poor compaction (refill). Conclusion: This shows that risk of subsidence factors judged by experts is similar with JIS' cases of ground subsidence.