• The Journal of the Convergence on Culture Technology
• /
• v.9 no.2
• /
• pp.307-312
• /
• 2023

North Korea has already been using underground space for military purposes for decades, and is currently developing it as a key base for operating asymmetric forces. Accordingly, the special operations teams need fighting methods, weapon systems, and organizational structures to carry out subterranean operations. This paper presents an unmanned system platform for subterranean operations that combines tilt-rotor type drones, high-tech sensors, communication repeaters, and small robots, and a system that can be operated by special operation teams. Based on this, the survivability of the special operations teams can be strengthened and operational utility can be maximized. Afterwards, if Special Warfare Command collects collective intelligence based on the ideas related to subterranean operations presented in this paper and further develops these, it will be possible to drive subterranean operations doctrines, weapon systems, and organizational structures optimized for the battlefield on the Korean Theater of Operations in the near future.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.4C
• /
• pp.255-264
• /
• 2006

The auxiliary reinforcement method is normally applied to prevent a possible collapse of the tunnel face where the ground condition is not favorable or geologic information is not sufficient. Recently, several engineering approaches have been made to choose the effective reinforcement methods using expert system such as neural network and fuzzy theory field, among others. Even if the expert system has offered many decision aid tools to properly select the reinforcement method, the quantitative assessment items are not easy to estimate and this is why the data mining technique, widely used in the field of social science, medical treatment, banking and agriculture, is introduced in this study. Using decision tree together with PDA, the decision aids for reinforcement method based on field construction data are created to derive the field rules and future study will be concentrated on the application of the proposed methods in a variety of underground development cases.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.4D
• /
• pp.535-544
• /
• 2009

Even though Korea's national project - NGIS(National Geographic Information System) has been built since 1995 and the GIS database for underground facilities has also been built, not so many systems are utilizing those databases currently. Also, the waterworks GIS developed and operated by K-Water is not used effectively in supporting field works. In order to manage and operate the waterworks pipelines effectively, systematic supporting strategy must be established by adopting the state-of-the-art technology. In this research, a ubiquitous-based strategy for managing waterworks facilities is proposed to increase the usability of the existing related databases and to ensure the systematic way of distributing information. The current status of the existing waterworks GIS and GIS database were analyzed to achieve the goal. By studying the state-of-the-art technology, we found that importing the LBS technology to the databases is necessary. The results of these efforts are exclusive waterworks-mobile-terminals and LBS system supporting them. Furthermore, the applicability of the ubiquitous technology to waterworks has been examined to realize the real-time waterworks management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.389-391
• /
• 2022

Efforts by the Ministry of Environment and local governments in Korea are continuing to manage the aging of water supply and sewage buried underground. With the support of the Korea Institute of Environmental Industry and Technology's water and sewage innovation technology development project, it is conducting a project to predict and exchange accidents due to aging, and to apply smart functions to new buried pipes. As one of these studies, this paper proposes the design of a dashboard concept model for digital twin-based smart pipe health monitoring, one of the key features of the entire study. Since remote control and monitoring are one of the main functions, distributed transmission and reception agents are deployed to visualize monitoring situations in real time and to increase user affinity by deploying intuitive UI. To validate the design of this proposed special digital twin based smart pipe state monitoring, we construct the conceptual model level and measure the agent effectiveness to validate its excellence.

• Geomechanics and Engineering
• /
• v.31 no.1
• /
• pp.53-69
• /
• 2022

In densely built areas, the development of underground transportation systems often involves twin excavations, which are sometimes unavoidably constructed adjacent to existing piled foundations. Because soil stiffness degrades with induced stress release and shear strain during excavation, it is vital to investigate the piled raft responses to subsequent excavation after the first tunnel in a twin-excavation system. The effects of deep excavations on existing piled foundations have been extensively investigated, but the influence of twin excavations on a piled raft is seldom reported in the literature. In this study, three-dimensional numerical analyses were carried out to investigate the influence of sand density on an existing piled raft (with a working load on top of the raft) due to twin excavations. A wide range of relative density (D_r) from loosest (30%), loose to medium (50% and 70%), and densest (90%) were selected to investigate the effects on settlement and load transfer mechanism of the piled raft during twin excavations. An advanced hypoplastic sand model (which can capture small-strain stiffness and stress-state dependent dilatancy of sand) was adopted. The model parameters are calibrated against centrifuge test results in sand reported in the literature. From the computed results, it is found that twin excavations in loose sand (D_r=30%) caused the most significant settlement. This is because of the higher stiffness of denser sand (D_r=90%) than that of loose sand. In contrast, a much larger tilting (maximum magnitude=0.18%) was computed in dense sand than in loose sand after the completion of the first excavation. As far as the load transfer mechanism along the piles is concerned, an upward load transfer to mobilize shaft resistance is observed in loose sand. On the contrary, a downward load transfer is observed in dense sand.

• International conference on construction engineering and project management
• /
• 2013.01a
• /
• pp.634-639
• /
• 2013

The aim of the study is to develop the 3D visualization of Building Information Model and integrated 4D model for optimization of resources in the construction project. This study discuss the process of methodology and creation of 4D model of the project and simulate it to monitor the workflow at the site. Different stages of the construction process and activities are generated by using Revit and MS Project. MS project has been used for creation of the schedules and these are linked with the Revit for 3D modeling. The time used as the fourth dimension and 4D model created by using Navisworks Time liner software. Narges shopping center is presented as a case study to realize the actual uses and benefits of Building Information Model (BIM). Narges shopping mall is located in Tehran, Iran. As a part of Hekmat master plan, Narges shopping center is an 11 stores building with a total area of 30000 Sq.m. This shopping and entertainment center is comprised of 150 retails and two multi-use public halls with a capacity of 400 persons each and underground parking with total 400 parking space. The main purpose of architecture was to create an urban public center along with its revolving, spiral like form and an ever changing continuous façade by means of different colors, materials, which is in harmony with the other building of the master plan. The approximate cost of the project is $17 million and duration of the project schedule is 30 months. The developed Building Information Model enabled us to identify the potential collisions or clashes between various structural and architectural systems. 4D model has been used for limiting the interaction between subcontractors installing the different systems so rework could be avoided and productivity maximized. It is also observed that the utility of BIM for construction stimulation and clash detection is the best suitable method. Clash detection before the implementation of work is highly recommended to avoid rework.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2023.04a
• /
• pp.79-79
• /
• 2023

With the development of digital technology, the size of the smart agriculture market at home and abroad is rapidly expanding. It is necessary to establish a foundation for sustainable precision agriculture in order to respond to the aging of rural areas and labor shortages. This study was conducted to establish an automated digital agricultural test bed for soybean production management using data suitable for agricultural environmental conditions in Korea and to demonstrate the field of leading complexes. In order to manage water smartly, we installed a subsurface drip irrigation system in the upland field and an underground water level control system in the paddy field. Based on data collected from sensors, water management was controlled by utilizing an integrated control system. Irrigation was carried out when the soil moisture was less than 20%. For effective water management, soil moisture was measured at the surface, 15cm, and 30cm depth. The main growth characteristics and yield, such as stem length, number of branches, and number of nodes of the main stem, were investigated during the main growth period. During the operation of the test bed, drought appeared during the early vegetative growth period and maturity period, but in the open field smart agriculture test bed, water was automatically supplied, reducing labor by 53% and increasing yield by 2%. A test bed was installed for each field digital farming element technology, and it is planned to verify it once more this year. In the future, we plan to expand the field digital farming technology developed for leading farmers to the field.

• Tunnel and Underground Space
• /
• v.33 no.5
• /
• pp.299-311
• /
• 2023

Continuous excavation technologies are developed to improve the excavation rate of shield TBM. Continuous excavation is a technology that provides thrust to segments, excluding being installed one, to reduce tunneling downtime. This paper investigated the prior technology related to continuous excavation segments. The main technology was classified into helical segment, honeycomb segment, and conventional segment methods. The helical segment method has not been applied in actual construction yet, and the honeycomb segment method has not succeeded in commercialization. The continuous excavation method using conventional segments has been successfully demonstrated. The thrust force and operation method of the thrust jacks for the semi-continuous technology were analyzed. Continuous excavation TBM research is also progressing in Korea, and through the analysis of successful cases, the need to develop independent continuous excavation methods has been identified.

• Journal of the Korean Geotechnical Society
• /
• v.40 no.1
• /
• pp.55-63
• /
• 2024

In this study, a thermomechanical numerical model was developed to evaluate the stability of energy slabs. First, a wall-type energy slab was installed in a residential underground parking lot, and thermal performance tests were conducted. Based on the tests, a numerical thermohydraulics model of the energy slab was developed to accurately simulate the thermal behavior in thermal performance tests. Finally, utilizing the temperature data acquired using the developed model, a thermomechanical numerical model of the energy slab was established. The thermomechanical model was then used to simulate the thermal stresses induced by operating the energy slab. The results demonstrated a maximum thermal stress of 5,300 kPa, which highlights the need to utilize cement mortar with sufficient tensile strength to realize stable operation of the energy slab.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.1
• /
• pp.507-516
• /
• 2024

Through the use and development of underground spaces, subways have become a representative means of transportation in the city center. Due to the extension of subway lines and the increase in the number of subway users, there is a risk that safety for evacuating human lives in case of fire will not be secured. Therefore, this study tried to identify citizens' perceptions of evacuation facilities through questionnaires and find alternatives. An online survey of 115 subway passengers was conducted to learn about citizens' awareness of subway evacuation facilities. As a result of the survey, awareness of evacuation facilities was high in the order of guidance lights, life-saving devices, emergency lights and portable lights, special evacuation stairs, and evacuation stairs. In addition, the majority of the respondents said they were not well aware of evacuation facilities, and people's indifference was the most common cause. As a solution to the lack of awareness, responses to active advertising and promotion, education and experience activities were the highest.