• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.43-46
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• 2006

The Hwangtoh is one of the traditional construction material used in wall, plastering material, and ondol (Korean underfloor heating system) with stone and wood. It is an important greenness material and it has much advantages such as; high storage of heat, auto-purification, antibiotic ability, and emission of far infrared rays. But, it is not developed and not used in modern construction because of its low strength and properties of dry shrinkage crack. According to the recent researches and studies, it is evaluated for natural pozzolanic material like flyash or pozzolan. It's possibility on construction material is high because it's chemical and mineralogical proportion is like as Metakaolin and Kaolinite. In this point of view, this study aims to analyze the physical properties on Hwangtoh mortar through an experiment with various activation condition of Hwangtoh, which is natural pozzolanic material, for the purpose of increase the using possibility in construction material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.55-56
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• 2018

In order to reduce the risk of accidents, we proposed a construction safety management system combined with wearable device and LoRa (Low-Range Wireless Network) communication method to apply the usefulness of Internet (IoT) technology which means "everything connected". to construction safety management Management system. The proposed wearable safety device is a device that relays information exchange between wearable safety device and safety management server by LoRa wireless communication method. The safety management server can store workers bio-data and perform big data analysis. If a risk factor is determined from the analysis result, a warning is sent to the wearable safety device and the manager's application. The goal of this system is to prevent construction workers from entering the dangerous area that is not suitable for work, and to prevent safety accidents caused by human cause by detecting abnormal condition during work.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.126-127
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• 2018

Rebar work is important in terms of cost and process of reinforced concrete construction along with formwork and concrete construction, and the quality of reinforced concrete construction has a great influence on the safety and durability of the structure. Therefore it is important to thoroughly inspect the steel reinforcement after casting the concrete because it is difficult to confirm the actual condition of the reinforcement. The purpose of this study is to develop an augmented reality system to visualize the records of bar placing work, which is increasingly utilized in the construction field. In order to improve maintenance of reinforced concrete, this study suggests a plan to effectively manage the drawing information including the structural drawing, the placing drawing, and the photographed image at the construction and inspection stage, and develop a system that utilizes augmented reality technology that can display the state of the inside of a concrete structure by superimposing it on actual environment.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1148-1154
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• 2009

This study focus on the suggestion of application manual using assembling reference plane design & standard finish material basis upon material classification code. We see it will function as a tool of a linkage between building design and construction standarization in order to enlarge the applicability of house building material that is produced by the module plan. For a estabilishing of this condition, it is neccessary to link the standardization's result of material--design--construction field. According to this neccessity, we are going to suggest information factor that can make relative business manager easily approach to the standardization practical task.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.179-182
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• 2015

Detecting and assessing human-related risks is critical to improve the on-site safety condition and reduce the loss in lives, time and budget for construction industry. Recent research in neural science and psychology suggest inattentional blindness that caused by overload in working memory is the major cause of unexpected human related accidents. Due to the limitation of human mental workload, laborers are vulnerable to unexpected hazards while focusing on complicated and dangerous construction tasks. Therefore, detecting the risk perception abilities of workers could help to identify vulnerable individuals and reduce unexpected injuries. However, there are no available measurement approaches or devices capable of monitoring construction workers' mental conditions. The research proposed in this paper aims to develop such a measurement framework to evaluate hazards through monitoring electroencephalogram of labors. The research team developed a wearable safety monitoring helmet, which can collect the brain waves of users for analysis. A bispectrum approach has been developed in this paper to enrich the data source and improve accuracy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.6
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• pp.98-105
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• 2000

Recently, the construction method of high pressure jet-grouting is in wide-use, for the purpose of structure foundation ground, reinforcing of ground behind propped retaining walls and cut-off in order to perform safe construction of underground excavation work. This study was performed a serious of tests of field permeability and unconfined compressive strength upon ground improved established on the ground behind propped retaining walls and examined proper jet mechanism by changing the construction parameter value of high pressure jet-grouting. In addition, we got the conclusion like the followings as a result of inspecting the condition of earth pressure distribution and deformation, using elasto-plastic method and FEM. 1. In that characteristics of strength of ground improved, with the same condition of construction parameter, unconfined compressive strength of sand gravel is shown bigger than that of silty sand by about 1.6 times and cut-off effect is shown to have effect of reducing the permeability of original ground by about 10$^{-2}$ ~10$^{-3}$ cm/s. 2. As a result of analysis of figures of horizontal displacing quantity of propped retaining walls materials regarding before and after High pressure jet- grouting through FEM, the reducing quantity of 0.1~0.3mm in maximum horizontal displacement is shown.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.208-218
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• 2006

It is very important to evaluate predictable problems diversely such as stability of a tunnel and structures when tunnel is inevitably constructed in the area where is adjacent to a structure and low overburden. Double electrified railway design on the third section of Donghae-Nambu line studied in this paper has some problems mentioned above. So more careful works are required before construction. In this study, ground surrounding is composed of faults, fault zone and set back about 13m from a Buddhist temple located on the upper part of the tunnel. From these conditions, this case study presents proper methods considering ground condition, effects of blasting and civil petitions. It is tried to make the tunnel and Buddhist temple stable by analytical technique and analysis of existing cases. And design considering stability of tunnel and adjacent structure during operation is carried out as well. Especially, environmentally friendly railway tunnel which is appropriate to the local condition and surroundings is designed by minimizing noise and vibration that is able to occur during construction and train service. From now on, this study is helpful to better design in the case of tunnel design which has to consider civil petition.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.398-403
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• 2009

The theoretical bases on characteristics of heat release rate in compartment of building for scenario of smoke management are introduced and the numerical applications to simple compartment model are carried out. The growth stage which is important for smoke management design is modelled as t-squared fire curve including fire growth coefficient with related to growth rate. The conditions for the happening of flashover is presented such as $600^{\circ}C$ of temperature or $20kW/m^2$ of radiation heat flux. After the flashover happen, the fire in compartment changes to fully developed fire having the characteristics of ventilation-controlled fire. As the result of numerical analysis to simple compartment model, the time to reach 900K under ceiling for condition of medium growth is twice for condition of fast growth.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1923-1924
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• 1996

Some part of the route in KEPCO 765kV transmission line being constructed passes through a high mountain area which is 800m above the sea level (Taebaek, Sabuk area in Gangwon province). This area is the top part of Taebaek mountains corresponding to the backbone of korean peninsula and has lots of snow during the winter season because the winter seasonal wind gone up along the mountainside of Taebaek Mts. meets open air of the East sea. KEPCO has experienced 63 faults of T/L between 1968 and 1993 in this area, which is a very serious problem. Especially 154kV Hwang-Ji T/L fault in 1990, 2 was a unprecedented case which needs to be analyzed carefully to take proper measures. After reviewing ice and snow loading conditions and analyzing the fault of Hwang-Ji T/L, we're going to determine the revisement of ice and snow loading condition in this area to increase reliability of 765kV transmission line.

• Journal of the Korea Institute of Building Construction
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• v.3 no.2
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• pp.141-148
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• 2003

This study deals with the estimation of material properties according to the construction condition for water-soluble rubberized asphalt waterproofing material of spray type. In this study, the waterproofing material property by the spray construction method is suggested by means of estimation its tensile performance and temperature dependency according to mix proportion ratio(4:1, 8:1), referenced viscosity and solid content (A:360cps, 76%, B:580cps, 79%, C:490cps, 70%), spray angle($30^{\circ}$, $45^{\circ}$, $60^{\circ}$), and spray distance(30cm, 50cm, 70cm). The result of testing are as follows. (1) The mix proportion ratio of principal agent and hardener is 4:1. (2) The viscosity referenced and solid content are 490cps and 70%. (3) The spray angle referenced is $45.^{\circ}$ (4) The distance referenced from concrete surface to spray gun is 40~50cm.