• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.922-929
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• 2022

Purpose: The purpose of this paper is to develop a deep learning model to detect fire extinguishers in images taken from CCTVs in underground utility tunnels. Method: Various fire extinguisher images were collected for detection of fire extinguishers in the running-based underground utility tunnel, and a model applying the One-stage Detector method was developed based on the CNN algorithm. Result: The detection rate of fire extinguishers photographed within 10m through CCTV video in the underground common area is over 96%, showing excellent detection rate. However, it was confirmed that the fire extinguisher object detection rate drops sharply at a distance of 10m or more, in a state where it is difficult to see with the naked eye. Conclusion: This paper develops a model for detecting fire extinguisher objects in underground common areas, and the model shows high performance, and it is judged that it can be used for underground common area digital twin model synchronizing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.297-307
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• 2017

There are many underground spaces available in an urban environment and they represent an important factor for efficient land use. Especially, underground shopping centers perform both physical and commercial functions at the same time and are frequently used as a means of achieving the revitalization of the city center. However, the underground shopping centers that were developed in the past sometimes led to recession due to their deterioration. This study was carried out for the purpose of proposing alternative methods for the (revitalization) of underground shopping centers. A survey was conducted on seven underground shopping centers in the Busan metropolitan area to understand the factors that determine their user satisfaction and future improvement. The survey data was analyzed using an ordered logit model. As a result of the analysis, service satisfaction, underground environment satisfaction and public facility satisfaction were selected as significant variables. It was concluded that it is necessary to take these factors into consideration, appropriately, when developing a new or renewing an existing underground shopping mall.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.211-214
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• 2002

It becomes difficult and high in cost to construct new ducts and/or tunnels for power cable in Metropolitan area. This paper presents the possible application of a HTS superconducting power cable for transmitting electric power in metropolitan areas, reflecting its important distinction such as compactness for installation in underground ducts and considerably economical efficiency comparable to present underground cables. In this paper, review of transmission capacity and voltage class of compact HTS cable which should be applied to existing ducts was performed.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.1033-1036
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• 2010

Since Jeju island has depended a water resource on the underground water because of a poor development of the surface flow, Jeju island is in need of the surface resource development to prevent the future shortage of the underground water due to excessive development and use of it. The study shows that the SWAT model(continuous rainfall-runoff model) is applied to estimate the outflow in the drainage watershed area, where it has been urbanized through the change of the land, such as a tourism development, cultivation, housing, and impervious layer road development. Near watershed area in Jeju island, weather and topographical SWAT input data were collected, and compared the outflow change of past and present.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.1057-1063
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• 2009

Since Jeju island has depended a water resource on the underground water because of a poor development of the surface flow, Jeju island is in need of the surface resource development to prevent the future shortage of the underground water due to excessive development and use of it. The study shows that the SWAT model(continuous rainfall-runoff model) is applied to estimate the outflow in the drainage watershed area, where it has been urbanized through the change of the land, such as a tourism development, cultivation, housing, and impervious layer road development. Near Oaedo watershed area in Jeju island, weather and topographical SWAT input data were collected, and compared the outflow change of past and present.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.32-38
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• 1991

Airborne suspended particulate concentration in drilling sites of underground coal mines in Taebaek area was evaluated. And respirable coal dust exposure level was evaluated. Airborne suspended particulate mass include total suspended particle(TSP) and thoracic particle(TPM). TSP (by open-face filter holder) and TPM(by elutriator) concentration were determined by low volume air samplers. Personal air samplers were attached to the coal workers including drillers, coal cutters, and their assistants. Normality and log-normality of TSP, TPM, and respirable dust(RPM) concentration were tested by Kolmogorov-Smirnov one-sample test. Differences of means of TSP, TPM, and RPM concentration were tested by paired t-test. Relation between TSP, TPM, and RPM with pairs were tested by regression test and Pearson's correlation.

• 한국전산유체공학회:학술대회논문집
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• 2007.04a
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• pp.59-63
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• 2007

With the recent increasing demand on the high-performance buildings, there has been a rapid growth in the application of the Computational Fluid Dynamics to the Building design. The conceptual ventilation design of the underground parking area currently under construction is validated using the CFD-ACE+. It has been found that the conceptual ventilation design quantitively satisfies the legal standards. However, the highly concentrated region of CO is predicted. The positions and blowing directions of ventilating lane are changed based on the previously predicted concentration distributions. The highly concentrated region of CO is slightly reduced, but not much change has been observed. Two more fang are installed and the positions and blowing directions of the fans are modified so that the highly concentrated region of CO is minimized.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.231-236
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• 2002

The understanding of underground geologic structures is of great importance for the surface and subsurface constructions, prevention of natural hazards such as land-slides and subsidence, and many other areas. To get the information on the geologic conditions, many of investigations such as geologic survey, geophysical explorations, testings on the physical properties of rocks, drilling tests and logging, and groundwater surveys are usually conducted, and tremendous data are collected accordingly. In general, however, these huge amount of data are interpreted in the individual areas only. If these data are analyzed collectively, much more information on the geologic conditions can be obtained. In this study, 3D visualization of borehole logging data is attempted. Borehole logging data are obtained at the urban subsidence area. To compare the 3D logging data with other geologic and geophysical data such as resistivity tomography data, interface module was developed. The 3D visualization of logging data and the comparison with other data can be helpful for the understanding of underground geologic structures.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.15-23
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• 2012

This study was accomplished by analyzing the change of land cover pattern in high-rise buildings in Korea. For this study, we selected 15 locations of high-rise buildings. The ratio of average building coverage and paved area was 79.7%, and both green and water area were low, relatively. The biotope area factor of the site showed low percentage by 15.90% due to the underground space development. As a result of correlation analysis between the time of construction and land-cover type, building coverage has been decreased according to the stream of time. However, biotope area factor has been increased And, the paved area has m correlation. It was identified that reducing paved area is effective to enhance the ecological functions of a high-rise building outdoor.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.2
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• pp.147-155
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• 2013

In this paper structural analysis of underground electrical power cable structures which is excavated below the surface of the earth in the downtown area is carried out considering the effect of construction sequence. There are many various life-line facilities below the surface of the earth in the downtown area. MPDAP was used for finite element analysis of underground electrical power cable structures. Three typical sections are simulated by finite element models. Unbalanced equilibrium problems may be occurred when conventional finite element procedures were used for simulation of tunnel excavation. Therefore equilibrium perturbation concept was applied to solve these problems. The effects of time-dependent deformations in advancing tunnel excavation are considered in the stages of construction sequences as using the load distribution factor. It is shown that values of maximum displacement of both soil and rock surrounding underground electrical power cable structures obtained by our numerical studies are less than allowable values.