• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.8
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• pp.1374-1381
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• 2010

This paper discusses the characteristics of sheath circulating current as well as the development and application of new software for underground power cable systems. Generally, in steady state, high sheath circulating current causes the increase of sheath temperature and thermal resistance which leads to the steeply reduction of the power capacity. Therefore, the exact calculation of sheath circulating current is required for analysis about the influence of high sheath current on permissible current. In this paper, Power Cable Simulator is developed for calculation of the sheath current. It can analyse the sheath current by real time. It is also easier to use than conventional software, such as EMTP and CabSim, because all the data for calculating the cable parameters are stored in a database(DB) within Power Cable Simulator. In addition, the accuracy of Power Cable Simulator is also proved through the comparison among the current calculated by Power Cable Simulator, EMTP and Cabsim with measured current.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.60-67
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• 2008

The spatial limitations of urban environments in general lead to invention and design of a wide range of underground transportation systems such as subways, underground roads and paths, etc. Among them, the application of subway systems in metropolitan cities is most commonly observed to ease those confronted difficulties on this purpose. It in turn leaves passengers and workers to be exposed to indoor air potentially polluted by various sources existing in this underground environment. Specifically when considering the IAQ in a subway station, there exist many IAQ-related parameters to be counted either as individual or as integrated exposures. In this study, a model system has been developed to manage the general IAQ in a subway station. Field survey and $CO_2$ measurements were initially conducted to analyze and understand the relationship between the indoor and outdoor air quality while considering the internal pollution sources such as passengers, subway trains, etc. The measurement data were then employed for the model development with other static information. For the model development, the algorithm of simple continuity was built and applied to model the subway IAQ concerned. In this paper, the recent updated draft version of model developed will be reported and demonstrated.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.4
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• pp.489-502
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• 2023

This article presents the crucial role played by the French underground research laboratory (URL) in initiating the deep geological repository project Cigéo. In January 2023, Andra finalized the license application for the initial construction of Cigéo. Depending on Government's decision, the construction of Cigéo may be authorized around 2027. Cigéo is the result of a National program, launched in 1991, aiming to safely manage high-level and intermediate level long-lived radioactive wastes. This National program is based on four principles: 1) excellent science and technical knowledge, 2) safety and security as primary goals for waste management, 3) high requirements for environment protection, 4) transparent and open-public exchanges preceding the democratic decisions and orientations by the Parliament. The research and development (R&D) activities carried out in the URL supported the design and the safety demonstration of the Cigéo project. Moreover, running the URL has provided an opportunity to gain practical experience with regard to the security of underground operations, assessment of environmental impacts, and involvement of the public in the preparation of decisions. The practices implemented have helped gradually build confidence in the Cigéo project.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.63-69
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• 2014

Due to population growth and urban development in construction technology has expanded living space, underground construction as public transport as has been extended to the ground and underground urban traffic congestion increases. This underpass Stations sphere of influence this development was the center of the living space, space-time became a cultural space. However underpass ground space and time and space are enormous difficulties in contrast visibility due to smoke when light levels are low fire occurs, momentary loss of judgment errors due to a sense of orientation, rapid diffusion and ambient oxygen deficiency due to acquisition limitations, such as the Open resulting in property damage and personal injury. The purpose of this study is to analyze the existing system with respect to the address of the underground shopping center and system for presenting an address to the underground shopping mall in the basement of the straight and circular in connection with the street name address. Also can be known only to evacuate their citizens to address the position in the event of a fire inside the basement through the underground shopping mall address standardization system, the fire department only address exact location is being judged will be identified.

• Tunnel and Underground Space
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• v.30 no.2
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• pp.109-135
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• 2020

Globally, the deepening depth in the underground is a situation of the high interest for a purpose of the development of various facilities. The development of deep underground space should be based on the structural stability of rocks. Spalling is known to have an impact on the structural stability degradation in deep underground space. As an attempt to predict spalling, many researchers have proposed predicted conditions in accordance with stress states which occur around the tunnel, rock conditions, and types of rock. In addition, the analysis on spalling method has been verified by using computer modeling such as FLAC, EXAMINE, Insight 2D, UDEC and FRACOD, along with in-situ measurement results. In Canada URL (Underground Research Tunnel), CWFS model (Cohesion Weakening Frictional Strengthening) was used to precisely predict for the state of spalling, comparing spalling modeling. CWFS model has been identified as a reliable method for predicting such phenomena. This study aims to analyze several cases of spalling, and then make a comparison between the conditions for spalling occurrence and the predicted results of model CWFS. With this, it investigates the applicability of prediction of spalling, targeting pillar under deep depth condition.

• Tunnel and Underground Space
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• v.22 no.2
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• pp.120-129
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• 2012

Recently, mining facilities have being installed in an underground space according to a social demand for environment-friendly mine development. The underground structures for mining facilities usually requires a large volume of space with width greater than height, and thus the stability assessment of the large-scale underground mine structure is an important issue. In this study, we analysed a factor of safety based on strength reduction method, and proposed a numerical design approach to determining the dimension of underground mine structures in combination with a strength reduction method and a multivariate regression analysis. Input design parameters considered in the present study were the stress ratio and shear strength of rock mass, and the width and cover depth of underground mine structures. The stabilities of underground mine structures were assessed in terms of factor of safety under different conditions of the above input parameters. It was calculated by the strength reduction method, and several kinds of fit functions were obtained through various multivariate regression analyses. Using a best-fit regression model, we proposed the charts which provide preliminary design information on the dimension of underground mine structures.

• Proceedings of the Korean Geotechical Society Conference
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• 1994.09a
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• pp.149-157
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• 1994

In this study two dimensional visco-plastic finite element model capable of handling the multi-step excavation was developed for investigating the effect of excavation support sequences on the behavior of underground openings in the jointed rock mass. First, the finite element model which is capable of handling the multi-step excavation is developed and verified. And then the model is combined with visco-plastic joint model. Ubiquitous joint pattern was considered in the model and joint properties in cach set were assumed to be indentical. Passive, full-grouted rockbolts were cosidered in the numerical model. The visco-plastic deformations of joints and rockbolts were assumed to be governed by Mohr-Conlomb and von Mises yield criteria, respectively. With the ability of removing elements, the model can simulate the multi-step excavation-suppport sequences. The reliability and applicability of the model to the stability analysis for the underground excavation in pratice was checked by simulating the behavior of underground crude oil storage caverns under construction.

• 전자공학회논문지 IE
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• v.44 no.2
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• pp.41-46
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• 2007

In this paper, we have proposed Station Safety Management System to protect station accident. we establish a sensor part near an underground rail. If a passenger approaches an underground rail, at first, lamp is shining and warning sound is ringing. nevertheless he approaches end of underground rail, At the same time, lamp is shining, warning sound is ringing, this information transfer server and train using wireless LAN. We makes this system using low cost in comparison with another system.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.69-72
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• 2009

In this paper, the Stand-alone underground water pumping system was developed that is consist of Submersible Pump (AC type), Photovoltaic Array and Power converter by the application of solar energy. And also wish to introduce system that is possible to supply of drinking water or water for agriculture using solar energy at desertification area or a Off-grid area, interior etc. and operation test results. This system can use in deep tube well of 200m range with common Submersible Pump and maximized to the quantity of pumping through M.P.P.T control. Also system availability raised through apply various driving mode.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.362-365
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• 2007

In this paper we present development process and results of some cases for underground pad transformer and switchgear. Some characteristic factors was considered and tested to improve the functions of the case, such as natural convection of cooling air between the internal and external cases, properties of material that used as external panel etc. Proposed designs and functional characteristics will be adapted to making the cases of underground facilities after the elaborated tests. The results obtained from this study will improve the scenery of a street.