• Geophysics and Geophysical Exploration
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• v.26 no.4
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• pp.211-228
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• 2023

Ground-penetrating radar (GPR) surveys are commonly used to monitor embankments, which is a nondestructive geophysical method. The results of GPR surveys can be complex, depending on the situation, and data processing and interpretation are subject to expert experiences, potentially resulting in false detection. Additionally, this process is time-intensive. Consequently, various studies have been undertaken to detect cavities in GPR survey data using deep learning methods. Deep-learning-based approaches require abundant data for training, but GPR field survey data are often scarce due to cost and other factors constaining field studies. Therefore, in this study, a deep- learning-based model was developed for embankment GPR survey cavity detection using data augmentation strategies. A dataset was constructed by collecting survey data over several years from the same embankment. A you look only once (YOLO) model, commonly used in computer vision for object detection, was employed for this purpose. By comparing and analyzing various strategies, the optimal data augmentation approach was determined. After initial model development, a stepwise process was employed, including box clustering, transfer learning, self-ensemble, and model ensemble techniques, to enhance the final model performance. The model performance was evaluated, with the results demonstrating its effectiveness in detecting cavities in embankment GPR survey data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.721-733
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• 2023

As the frequency of extreme rainfall events increase due to climate change, climate change adaptation measures have been proposed by the central and local governments. In order to reduce flood damage in urban areas, various flood response policies, such as low impact development techniques and enhancement of the capacity of rainwater drainage networks, have been proposed. When these policies are established, regional characteristics and policy-effectiveness from the cost-benefit perspective must be considered for the flood mitigation measures. In this study, capacity enhancement of rainwater pipe networks and low impact development techniques including green roof and permeable pavement techniques are selected. And the flood reduction effect of the target watershed, Gwanak campus of Seoul National University, was analyzed using SWMM model which is an urban runoff simulation model. In addition, along with the quantified urban flooding reduction outputs, construction and operation costs for various policy scenarios were calculated so that cost-benefit analyses were conducted to analyze the effectiveness of the applied policy scenarios. As a result of cost-benefit analysis, a policy that adopts both permeable pavement and rainwater pipe expansion was selected as the best cost-effective scenario for flood mitigation. The research methodology, proposed in this study, is expected to be utilized for decision-making in the planning stage for flood mitigation measures for each region.

• Land and Housing Review
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• v.15 no.3
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• pp.61-77
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• 2024

This study analyzed the characteristics of land use changes around urban railway stations in peri-urban mixed-use cities. The research focused on four station areas along the Gyeonggang Line in Gwangju City, Gyeonggi Province, categorized into three phases based on their opening dates to analyze land use changes. The analysis method utilized building permit registry data from 2012 to 2020 within a 1 km radius of each station, at 250-meter intervals, examining temporal, spatial, and functional distributions. Statistical analysis employed SPSS for weighted cross-tabulation to explore differences in building permits and concentration levels among various building types. The findings revealed: firstly, peri-urban mixed-use city station areas exhibited the highest number of building permits at the time of opening; secondly, significant land use changes were observed within the 500-meter radius from the station; thirdly, residential buildings dominated, reflecting a trend towards housing supply-oriented land use changes; fourthly, cross-tabulation indicated significant differences in building permits across time, distance, and type (p < 0.01). Lastly, the concentration analysis revealed that residential buildings were distributed most evenly, while buildings for educational, social, and agricultural and fisheries purposes were distributed unevenly.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.5
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• pp.185-198
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• 2024

Tidal power is a technology that generates electricity by utilizing tidal current energy, and in recent years, with the advancement of technology, it has reached the stage of real sea performance test. However, in the case of Korea, there is a lack of construction experience and equipment, and work in fast flows such as the Uldolmok region involves various risk factors. In order to establish measures to reduce these risk factors, Korea's Occupational Safety and Health Act recommends performing a risk assessment to identify and manage risk factors that may occur during work in advance. Risk assessment is a process aimed at identifying and evaluating potential risk factors that may arise during work, with the goal of minimizing losses caused by accidents. Therefore, in this study, a risk assessment was conducted to identify risk factors that may occur during offshore O&M work of the 1 MW tidal current energy converter and to ensure the safety of workers and the environment. A total of 60 risk factors were identified, including marine and weather conditions, equipment and personnel, and work environments, and a qualitative risk assessment was conducted three times based on the judgment of several field experts.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.6
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• pp.695-711
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• 2024

Tunnel Boring Machine (TBM) is a mechanical device designed to excavate ground by rotating a cutter head equipped with cutting tools at the front. The excavation efficiency of a TBM is affected by the cutting performance of these rotation. Typically, the behavior of disk cutters, which are used as cutting tools in rock, is predicted using experimental models, with the Norwegian University of Science and Technology (NT NU) and Colorado School of Mines (CSM) models being the most commonly referenced. These models enable the calculation of disk cutter consumption and advance rates, which are then applied to empirical models for construction period planning. During the construction phase, excavation operations follow the plan; however, since TBM operation requires consideration of various factors such as thrust, RPM, and machine power, it often relies heavily on the experience and skill level of the operator. This reliance on subjective judgment rather than objective data can sometimes lead to inconsistent results. Therefore, in this study, a TBM planning and management system was developed by integrating the New Abrasion Test (NAT) model, process simulation, and TBM Advanced Driving Assistance System (TADAS) into the existing NTNU and CSM models. This system was applied to a domestic tunnel construction site, and the outcomes were compared and analyzed.

• Journal of Cadastre & Land InformatiX
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• v.54 no.2
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• pp.219-234
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• 2024

The purpose of this study is to present the possibility of effective integration of land-related big data and AVM in selection of a site for a waste disposal facility through simulation. As a difference from general AVM technology, KDI compensation ratio was utilized. The simulation analysis target areas were selected as candidate sites for additional facilities in Boryeong-si, Cheongyang-gun and Buyeo-gun in Chungcheongnam-do. In the big data analysis stage, spatial information and land characteristic information of the sites were analyzed environmental exclusion factors and economic factors. There was little difference in environmental factors among the three candidate sites, but in terms of economic aspects, the site in Buyeo-gun was found to have the lowest land cost, making it the most suitable area. When the integrated method of big data and AVM presented in this study was applied, the site candidate status analysis, which previously took 2 to 4 months, was shortened to within 1 month. This time saving can be an important factor in increasing the efficiency of the entire project. In addition, it is judged that compensation costs can be optimized through AVM and minimized costs due to social conflicts.

• Land and Housing Review
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• v.3 no.4
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• pp.369-378
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• 2012

In France, there are many forms of organizations based on the intercommunal solidarity for city development and management. The purpose of the collaboration among Communes is to achieve high quality and well-equipped service-delivery system through co-operation of public services needed grand finances : water supply and sewage system and waste disposal system etc. The cooperation among French Communes and its effects, even though these were owing to the existing French local administration system, continued throughout regional co-management and social co-development process. This study suggested some characteristics and implications of the collaborative-style French new-town development and management organizations focused on the EPA, SAN and CA. First, the role of developmental corporation like EPA and its collaborative structure of decision-making are meaningful, because in these ways many related Communes could share a goal of new town development. Second, the way of new town corporation (SAN) is important in the sense of enabling the Communes to collaborate with each others while maintaining autonomy, so those are not simply state-directed objects, which was very difficult in the former French local administration system. Finally, transforming to CA (Communautes d'agglomeration:city community), EPA as an intercommunal corporation is possible to extend its purpose to the domain of regional planning including new town and periphery areas and change its position to a subject which can practice Commune's sustainable development according to stages of city's development and maturity. The most important implication of this study on urban development in Korea is that administrative consultative council or association among local governments and related authorities need to be established and effectively operate because multi-stakeholders could share a goal of urban development and management through that.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1827-1836
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• 2022

Disasters that occur unexpectedly are difficult to predict. In addition, the scale and damage are increasing compared to the past. Sometimes one disaster can develop into another disaster. Among the four stages of disaster management, search and rescue are carried out in the response stage when an emergency occurs. Therefore, personnel such as firefighters who are put into the scene are put in at a lot of risk. In this respect, in the initial response process at the disaster site, robots are a technology with high potential to reduce damage to human life and property. In addition, Light Detection And Ranging (LiDAR) can acquire a relatively wide range of 3D information using a laser. Due to its high accuracy and precision, it is a very useful sensor when considering the characteristics of a disaster site. Therefore, in this study, development and experiments were conducted so that the robot could perform real-time monitoring at the disaster site. Multi-sensor module was developed by combining LiDAR, Inertial Measurement Unit (IMU) sensor, and computing board. Then, this module was mounted on the robot, and a customized Simultaneous Localization and Mapping (SLAM) algorithm was developed. A method for stably mounting a multi-sensor module to a robot to maintain optimal accuracy at disaster sites was studied. And to check the performance of the module, SLAM was tested inside the disaster building, and various SLAM algorithms and distance comparisons were performed. As a result, PackSLAM developed in this study showed lower error compared to other algorithms, showing the possibility of application in disaster sites. In the future, in order to further enhance usability at disaster sites, various experiments will be conducted by establishing a rough terrain environment with many obstacles.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.1
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• pp.13-28
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• 2023

This study examines the process of project promotion in Busan, which introduced the private participation-type consultative body for the first time in the country in the promotion stage of the private-initiated park development project, and introduced flexible application of the system and differentiated policy elements in the implementation process, and examines the operational characteristics and we tried to analyze performance, etc. As a result of the analysis, first, the preferred bidder was selected by introducing a mixed method in the project method, which is an independent project method that cannot be seen in other local governments. Second, by specifying guidelines considering the characteristics of each park and detailed guidelines such as the location, area, and maximum height of non-park facilities, criteria for establishing a rational development plan utilizing regional identity and the basis of evaluation standards were laid. Third, in the project process, transparency was secured through the delegation-type roundtable, in which the private sector performs the functions and roles of key actors, thereby preventing disputes such as suspicion of preferential treatment. Fourth, in order to improve the quality of park facilities to be donated and to secure design adequacy, after approval of the implementation plan, a general planner was introduced and construction project management (design stage) services were performed to promote efficient implementation and specialization of luxury parks in the region. As a result, the city of Busan carried out the project efficiently by conserving 5 parks from sunset, a park area of 2.25km², and reducing land compensation and park construction costs by KRW 740 billion. Reinforcement of the public nature of the private-initiated park development project was suggested. However, due to the application of these systems and verification procedures, the project period is prolonged, and park services are delayed along with the financial burden on private operators.