• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.680-688
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• 2008

On behalf of hazard mitigation, cases of investigation methods on levee are described. In general, failures of levee are caused by piping, water leakage through ground under the levee in Kimpo, Ilsan etc. Several phenomena against levees should be protected through consideration of analysis and quality control stage during construction. In this paper, protection methods against failures should be investigated by case studies.

• Journal of Conservation Science
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• v.38 no.4
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• pp.265-276
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• 2022

A long-term monitoring investigation at Sarushima Battery (Kanagawa, Japan), which is one of the modernization heritages was conducted from 2017.06 to 2020.12. The investigation of the temperature and relative humidity (RH), measurement of the amount of brick decay, and X-ray diffraction analysis of the brick decay was conducted to understand in detail the environment in which the historical brick structure, the state of deterioration, identify the factors of deterioration. Furthermore, it was discussed whether the suitability of these investigation methods for assessing the status, identifying the level of deterioration and the factors that led to deterioration at the historical brick heritages. It was found that the brick deterioration at the site progressed especially in two periods: in April, and from June to August. These periods coincided with the period when the RH inside the structure decreased, and the Toyo-gumi bricks were in the process of absorbing moisture. Several different types of salts were detected in brick decay, especially thenardite, which is considered highly hazardous and destructive during periods when the amount of brick decay increased. Therefore, the RH in the structure and the salts present in the bricks were identified as one of the factors in the deterioration of the bricks at the site. The methods used in this study are appropriate as the initial survey methods for investigating the current conditions and identifying the causes of deterioration because it is possible to understand the environment within the modernization heritages, grasp the details of deterioration progression, and identify the characteristics of deterioration progression and its factors through long-term investigation using the simple methods.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.335-339
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• 2003

The estimation of seawater intrusion into deep aquifers has been becoming an important subject in terms of site characterization for geological disposal of radioactive waste. Conventional direct-current resistivity methods have been used for ground water explorations and recently have been applied to environmental problems. However, electromagnetic methods are more practical and useful for such a deep investigation. We consider audio-frequency magnetotelluric (AMT) and surface-to-borehole electromagnetic (EM) tomography methods as promising tools for the investigation of deep aquifer. These methods were tested in the Hasunuma area, Chiba Prefecture, Japan. Although the study area is in an urban area, high-quality AMT data were acquired, which was mainly accomplished by night-time data recording and remote-reference data processing. One-dimensional inversion results of the AMT data revealed two extremely conductive zones, which is consistent with the electrical conductivity profile of pore water in core samples. It can be interpreted as the seawater intrusions into both zones. However, the chemical analysis of the groundwater sampled in the deep zone suggests that this groundwater must be fossil seawater that had been confined during sedimentation processes. In addition, the permeability coefficient of the deep layer is very low. Thus the deep conductive zone corresponds to the fossil seawater regarded as being difficult to flow.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.113-115
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• 2010

We studied the methods to utilize vehicle-based mobile mapping system for field investigation work of digital map generation process. Map layers which should be checked by field investigation were analyzed to find the possibility of being checked with data from vehicle-based mobile mapping system. Also new process for digital map generation were suggested to adopt field investigation by vehicle-based mobile mapping system. We performed field investigation work on the Kangneung area by vehicle-based mobile mapping on a trial bases and compared the results with a results from usual field investigation method.

• Structural Engineering and Mechanics
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• v.11 no.6
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• pp.651-662
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• 2001

In order to investigate the seismic behavior and seismic design methods in the transverse direction of a shield tunnel, a series of model shaking table tests and a two-dimensional finite element dynamic analysis on the tests are carried out. Two kinds of static analytical methods based on ground-tunnel composite finite element model and beam-spring element model are proposed, and the validity of the static analyses is verified by model shaking table tests. The investigation concerns the dynamic response behavior of a tunnel and the ground, the interaction between the tunnel and ground, and an evaluation of different seismic design methods. Results of the investigation indicate that the shield tunnel follows the surrounding ground in displacement and dynamic characteristics in the transverse direction; also, the static analytical methods proposed by the authors can be used directly as the seismic design methods in the transverse direction of a shield tunnel.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.1
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• pp.100-111
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• 2006

This study was carried out to increase the efficiency of site investigation through the evaluation of the applicable methods of investigation for cutting slope design. In an effort to find out the applicability of the method employed during the slope investigation, some tests were carried out on 6 subjects i.e location of weak zones, characteristics of discontinuities, distribution of strata, in situ tests for geo-technical properties, laboratory test and estimation of weathering. The method was highly applicable and produced expected results during the test of weak zones, discontinuities and distribution of strata. In order to apply the method to in- situ test for geo-technical properties and laboratory test on soil and rock slope, a statistic analysis of the existing data were required in advance. However its design applicability on rock slope was good although actual cases of application were not many due to limitation of the cases for investigation. The method was frequently referenced but not actually applied for anti seismic design test and estimation of weathering.

• Korean Security Journal
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• no.8
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• pp.379-407
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• 2004

The cyber-crime is one of the results occurring from the increased dependency toward information-telecommunication devices. Currently, the Korean National Police Agency and many other related law enforcement agencies have made efforts to respond against the cyber-crimes. However, the number of cyber-crime is increasing steadily. The worse problem is that the arresting rate for the cyber-crime has been decreased than before. The reasons of decreasing arresting rate come from many different kinds of cyber-crime methods with the developed computer and network technology, Also, the easy concealment of the cyber-crime by the violater and the difficulty of specification against the data objected to search and seizure make the crackdown difficult. The other difficulties come from the lack of professionally trained investigators, the lack of high-technological investigation devices, and the failure of the technology development for the search and seizure of evidences because of the budget deficit. That is to say, these phenomenon show the comprehensive problem of the cyber-police system. Accordingly, to respond against newly changed cyber-crime activities and to investigate effectively, the cyber-police has to take consideration into the professional reorganization of the cyber-police, the development of the investigation technology, and the adjustment of current cyber-crime laws. Most importantly, the cyber-police needs the high-technological investigation devices, the development of the investigation methods, and the training for the professional human resources with the enough budget support.J

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.276-282
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• 2003

The geoscientific study on geological disposal for radioactive wastes has established the stepwise site characterization program, methods and investigation technology. However the intrinsic properties of geological material such as heterogeneity and scale dependent properties make difficulty on satisfactory understanding of geological conditions. To avoid unnecessary time delay and unexpected extra-cost for site investigation, the accurate and complete site investigation program should be established in a stepwise manner and the QC programs for investigation methods and procedures. Moreover, the technical requirements and preferences for a repository should be distinguished and be assessed at the end of each investigation step.

• Geotechnical Engineering
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• v.7 no.2
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• pp.27-40
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• 1991

The Sunghak Campus, Dong-A University, which located at the excavated area of mountain, has been constructed year by year for about 10 years since 1978. The buildings, steep slopes, road and so on in the Campus area were damaged by heavy rainfall more than 200mm 1 day on August, 1989. The methods used for the investigation and repair methods of the damage are the preliminary investigation, the present condition survey, 50 by 50m grid survey, compasstraverse for locating outcrops, geopysical exploration, geologic survey, boring and laboratory soil testing. Based on the results of investigations, the causes of the failures have been evaluated, and the repair methods have been set up as horizontal drains, removal of the dangerous rock, retaining wall with subsurface drains, the elimination of colluvium and slope stabilization by use of precast concrete grids and so on.

• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.2
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• pp.7-14
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• 2018

Purpose: The outbreak of Middle East Respiratory Syndrome(MERS) in KOREA has brought up the demands for ventilation guideline and regulations for healthcare facilities since most of the infection was spreaded inside healthcare facility. Currently KOREA has no ventilation guideline or regulations covering entire section of healthcare facility. The purpose of this study is to investigate current ventilation methods in KOREA healthcare facilities to in future, propose ventilation guideline. Methods: Research of foreign counties ventilation guideline and regulation for healthcare facilities were conducted for reference. Field investigation with survey of 21 healthcare were conducted to identify the ventilation system and operating methods. Additionally survey for healthcare workers were conducted to observe the recognition related to ventilation system in healthcare facility. Results: The result showed that most of foreign countries ventilation guideline and regulation suggests similar items to reduce the spread of infection and maintain good indoor air quality. The investigation results indicated that fixed guideline for ventilation in healthcare facility were required due to different ventilation operating methods. Survey result of healthcare workers has told us that ventilation guideline and regulation is needed to prevent further infection. Implications: Absence of ventilation guideline and regulations for healthcare facility in KOREA is an urgent issue.