• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.754-762
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• 2021

Seamless wireless communication network access technology enables users to guarantee service continuity. Hence, it is necessary for disaster situations in which network service may be interrupted. The Multi-path router is a technology to improve network stability and strengthen field operability, particularly in a disaster environment where network failure can occur by providing high-performance data transmission using multi-communication networks and network security by VPN-based wireless IP. In this paper, a prototype system for an MPR-based wireless communication network was proposed to improve the operation performance for disaster field investigation applications. A comparative experiment was performed on various data transmission performances with the existing single wireless communication network. In addition, another experiment was conducted by measuring the data packet transmission and receiving performance in the existing/new wireless communication system first and then assessing the UDP transmission performance in a single router environment to understand the transmission capability of the new MPR. The experimental results showed that the sending and receiving performance was improved by approximately double that of the existing single wireless communication system. The proposed prototype system is expected to allow users to share and disseminate collected on-site data more quickly and efficiently during a disaster site investigation.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.671-672
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• 2015

Due to harsh conditions of disaster areas, understanding of current feature of collapsed buildings, terrain, and other infrastructures is critical issue for disaster managers. However, because of difficulties in acquiring the geographical information of the disaster site such as large disaster site and limited capability of rescue workers, comprehensive site investigation of current location of survivors buried under the remains of the building is not an easy task for disaster managers. To overcome these circumstances of disaster site, this study makes use of an unmanned aerial vehicle, commonly known as a drone to effectively acquire current image data from the large disaster areas. The framework of 3D model reconstruction of disaster site using aerial imagery acquired by drones was also presented. The proposed methodology is expected to assist rescue workers and disaster managers in achieving a rapid and accurate identification of survivors under the collapsed building.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.373-375
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• 2003

The subway, a typical electrified transit, is operated by the 1500 V DC-powered system with the overhead positive feeder and the rails negative return. This return path would bring about considerable stray current circuits, that is, from the bottom of rails to sell and then to the station ground, unless the rail-to-soil resistance is sufficiently high. The stray current can cause electrolytic corrosion of subway metallic structures and adjacent underground utilities. In this paper, we reports on-site investigation of the stray current condition, especially influenced by drainage method. The drainage method including both forced drainage and polarized drainage, extensively adopted as a countermeasure for electrolytic corrosion of underground pipelines, was found out to exert a harmful influence upon rail components as well as the pipelines.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.825-830
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• 2005

Cut slope and facility of management investigation is the protection of humans and properties. it is very important the prevention of disaster facility and the damage of the slope protection facility. It is very difficult to forecast slope stability, disaster possibility and collapse. It will be able to minimize the damage which it prepare against slope facility and cut slope of deformable investigation and collapse and the disaster. therefore those deformable investigation is important. Investigations execute upheaval, crack, sliding for slope and cut slope reinforcement. Investigation executes forecast in place where the construction problem, the effect which the damage in road traffic or the contiguity facility.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.266-292
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• 2007

Round Robin Test (RRT) on ground response analyses was conducted for three sites in Korea based on several site investigation data, which include borehole logs with the N values from standard penetration test (SPT) for all three sites and additionally cone tip resistance profiles for two sites. Three input earthquake motions together with the site investigation data were provided for the RRT. A total of 12 teams participating in this RRT presented the results of ground response analyses using equivalent-linear and/or nonlinear method. Each team determined input geotechnical properties by using empirical relationships and literatures based on own judgment, with the exception of the input motions. Herein, the characteristics of input motions were compared in terms of the frequency and period, and the selection of the depth to bedrock, on which the motions is impinged, was discussed considering geologic conditions in Korea. Furthermore, a variety of geotechnical properties such as shear wave velocity profiles and soil nonlinear curves were investigated with the input properties used in this RRT.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.62-67
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• 2012

Risk Assessment, a basis of health and safety management system, is an calamity prevention activity which regularly measure the level of a risk to passively improve potential hazard. A problem, the assessment not being improved to be applied to the construction work site where requires diversity and complexity, causes the assessment to be inefficient to bring quality results. A study on the investigates and compares the surveyed degree of recognitions of workers who works in companies executing the risk assessment By the investigation and comparison, it is expected to bring the better solution for early and efficient application for those companies which are not taking the risk assessment.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.1-11
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• 2012

Risk Assessment, a basis of health and safety management system, is an calamity prevention activity which regularly measure the level of a risk to passively improve potential hazard. A problem, the assessment not being improved to be applied to the construction work site where requires diversity and complexity, causes the assessment to be inefficient to bring quality results. A study on the investigates and compares the surveyed degree of recognitions of workers who works in companies executing the risk assessment By the investigation and comparison, it is expected to bring the better solution for early and efficient application for those companies which are not taking the risk assessment.

• Proceedings of the Korean Magnestics Society Conference
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• 2014.05a
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• pp.88-89
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• 2014

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.276.2-276
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• 1999

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.63-71
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• 2019

Work Guideline of Construction Quality Management was revised in July 2017, and it has changed the perception of scaffolding in South Korea. The on site investigation and survey was performed on manufacturers, leasing companies, and quality inspection agencies regarding the compliance with the guideline for the scaffolding and the related components brought to the site. Moreover, the related guidelines and identified unsatisfactory quality management items were analyzed by each subject. As a result, the major factors that cause the problems were reasonably deducted. The related regulations to prohibit the delivery of faulty scaffolding components to the construction site in order to secure the safety of the temporary structure was suggested.