• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.219-220
• /
• 2023

The thermal conductivity of the insulation material has a great influence on the heat transmission coefficient, which is currently used for energy evaluation of buildings. The thermal conductivity of insulation changes with changes in the environment, such as humidity and ultraviolet rays, and can be expected to with the passage of time. But there is a lack of data on this, so this study measured the thermal conductivity of organic insulation according to environmental conditions and time, As a result, in the case of XPS, the thermal conductivity value increased over time, which is estimated to be due to the decrease in insulation performance as the foaming gas escapes to the outside, and in the case of PIR class2 No.2 and PIR noncombustible, the increased thermal conductivity value is similar, but in the case of PIR class2 No.2, a relatively moderate increase can be seen, and in the case of PIR noncombustible, a large increase is seen at the beginning, which is judged to be due to the decrease in insulation performance as the internal foaming gas is substituted with air from the outside.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.6
• /
• pp.727-736
• /
• 2021

Road tunnel lengths are increasing. Some 1,300 tunnels with 1,102 km in length had been increased till 2019 from 2010. There are 64 tunnels over 3,000 m in length, with their total length adding up to 276.7 km. Safety facilities in the event of a tunnel fire are critical so as to prevent large-scale casualties. Standards for installing disaster prevention facilities are being proposed based on the guidelines of the Ministry of Land, Infrastructure and Transport, but they may be limited to deep underground tunnels. This study was undertaken to provide guidelines for the spacing of evacuation connection passages and the widths of evacuation connection doors. Evacuation with various spacing and widths was simulated in regards to evacuation time, which is the measure of safety, using the evacuation analysis simulation software EXODUS Ver.6.3 and the fire/smoke analysis software SMARTFIRE Ver.4.1. Evacuation connection gates with widths of 0.9 m and 1.2 m, and spacings of 150 m to 250 m, were set to every 20 m. In addition, longitudinal slopes of 6 % and 0 % were considered. It was determined to be safe when the evacuation completion time was shorter than the delay diffusion time. According to the simulation results, all occupants could complete evacuation before smoke spread regardless of the width of the evacuation connection door when the longitudinal slope was 6 % and the interval of evacuation connection passage was 150 m. When the evacuation connection passage spacing was 200 m and the evacuation connection gate width was 1.2 m, all occupants could evacuate when the longitudinal slope was 0 %. Due to difference in evacuation speed according to the longitudinal slope, the evacuation time with a 6 % slope was 114 seconds shorter (with the 190 m connection passage) than with a 0 % slope. A shorter spacing of evacuation connection passages may reduce the evacuation time, but this is difficult to implement in practice because of economic and structural limitations. If the width of the evacuation junction is 1.2 m, occupants could evacuate faster than with a 0.9 m width. When the width of a connection door is 1.2 m with appropriate connection passage spacing, it might provide a means to increase economic efficiency and resolve structural limitations while securing evacuation safety.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.10 no.3
• /
• pp.210-217
• /
• 2010

This paper presents integrated path planning and collision avoidance for an omni-directional mobile robot. In this scheme, the autonomous mobile robot finds the shortest path by the descendent gradient of a navigation function to reach a goal. In doing so, the robot based on the proposed approach attempts to overcome some of the typical problems that may pose to the conventional robot navigation. In particular, this paper presents a set of analysis for an omni-directional mobile robot to avoid trapped situations for two representative scenarios: 1) Ushaped deep narrow obstacle and 2) narrow passage problem between two obstacles. The proposed navigation scheme eliminates the nonfeasible area for the two cases by the help of the descendent gradient of the navigation function and the characteristics of an omni-directional mobile robot. The simulation results show that the proposed navigation scheme can effectively construct a path-planning system in the capability of reaching a goal and avoiding obstacles despite possible trapped situations under uncertain world knowledge.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.460-467
• /
• 2006

Some large accidents in tunnels in recent years, such as Mont Blanc, Gotthard and Tauern tunnels, have lead to an increasing attention for tunnel safety and necessity of tool for quantitative risk assesment of road tunnel. And the purpose of this study is to develop the quantitative risk assesment tool for the application of road tunnel. The objectives of this paper are as follows : (1) analyze of traffic accident rates in tunnel, (2) make out scenario for fire accidents, (3) develop the evacuation model and FED calculation model, (4) Present the results from quantitative risk assesment for the model tunnel according with the fire heat release rates and distances of cross passage.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.413-416
• /
• 2008

The concrete used most in construction materials. There is an overcrowded iron dimensions use of the concrete at time of the other concrete theory on the reinforcing rod back which did congestion and compares it with this, and there are more few dimensions of the aggregate than concrete, and quantity of aggregate passage is superior in mortar than concrete. If a volume rate of the aggregate writes mortar than concrete against this, therefore, unit amount increases, and quantity of paste increases and quantity of dry shrinkage than increase concrete. However, I let I regulate lay priest distribution of the aggregate, and the results rates increase and reduce unit amount and decrease quantity of dry shrinkage, and separation resistance and the gap passage characteristics are judged because it can be it in a substitute document of very superior concrete. I came to carry out the study that I watched to let I was useful a little more and do the improvement repair of a become building wall body, a basement pillar and repair reinforcement of the assistant in the reinforcing rod back, the old age when I made congestion here. I regulated lay priest distribution of the aggregate in the study and regulated substitution rate of the aggregate (40%, 50%, 60%) and divided W/C 30%, 40% standards and produced mortar and I compared quantity of air by this, slump, compression robbery and showed it this time.

• The Journal of the Korea Contents Association
• /
• v.11 no.9
• /
• pp.506-514
• /
• 2011

The purpose of this study is to look into whether there is a possibility to develop the image of the local community in conjunction with green tourism, thus to explore the concrete ways to vitalize local community with diversified green tourism programs. In the pursuit of relating the research of community image-building with comprehensive local characteristics, this study selected the case of Jung Bang I village near Daejeon and analyzed the case through both written materials and on-site investigation. As a result of analysis, first, it was found that community image-building contributed positive effects in terms of the commercialization of the local community and its revitalization. Second, it was observed that community image-building led to form a "green route" that played a role as a passage to link townspeople to the country. It was also verified that those country villages that succeeded in image-building provided the places where people could experience the country and arts, which showed the potential of their roles as educational opportunities. In conclusion, this study will be able to suggest the direction to where the green tourism and image-building projects of the small communities near towns should go, and also provide a substantial guideline to related people regarding how to operate and maintain the local community.

• Korean Institute of Interior Design Journal
• /
• v.13 no.5
• /
• pp.106-113
• /
• 2004

The purpose of this study is to present the dwelling space by attaching or inserting the mobile space unit to the fixed building by providing the temporary dwelling space for those suffering from flood disaster, natural disaster or solitary old people or the space and program that the completed building in the city can not provide such as temporary events in the bridge, passage space, walking space for the handicapped, stores located between street blocks, and plaza. Therefore, this study was intended to investigate temporary dwelling space through the composition of space and the experiment of the applicability of the program through the methods of movement, folding, module, expansion and evolution of mobile space. An attempt was made to apply the concept of ‘mobile space’ to the dwelling space not only with a focus on the freedom of variable and changeable physical movement but also with a focus on the existence of the nomad and the way of thinking that bleaks away from a given value system and code, creates a new value and continues to move to a new domain. This study attempted to analyze how the concept of ‘mobile space’ has been developed in what form and method they have been applied and interpreted in the historical background. It attempted to resolve the concepts of movement and mobility through the experiment so that they might apply to the space of contemporary city. This study attempted to experiment this possibility using the mobile space unit and apply it.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.19-24
• /
• 2008

Recently, the buildings have gradually become higher, more massive and more complex with high growth of economy and varieties of the patterns of people's living. Therefore we study a performance and Improving Methods of the fire compartment as a measure to minimize the damage of the people and property from the fire. Currently, under the economic crisis situation, we do not consider about prevention of disaster safety enough; safety investment evasion, safety carelessness, and management relaxation etc. Also in the aspect of regulation system, industrial technology and plan engineering, Korean techniques of preventing fire disasters are far behind of other advanced nations. At this point, we are in need of improving about it. When considering like this situation, we need more studies on the practical improvement in order to assure fire prevention for buildings. The fire compartment prevent from magnifying the fire to the wide area by compartment into specific area. From this, it is possible to minimize fire damage and property and secure emergency exit for life safety. This fire compartment has primary function to extinguish fire easily, and the openings and penetrations are important passage which makes the smoke and fire go away from the fire area to the contiguous space. This study suggests improving methods of domestic fire compartment efficiency standard through comparative analysis of overseas advanced provision and domestic provision about base element of the building fire prevention.

• Journal of the Korea Institute of Building Construction
• /
• v.3 no.3
• /
• pp.83-90
• /
• 2003

This study examines the material characteristics of fibers and their influences on reinforced concrete through the tests of reinforced concrete by the types of fibers including non-reinforced, steel, polypropylene and cellulose fibers and the test of compressive strength and reinforced concrete beam without shear reinforcement and consequently it obtains the following conclusions. As a result of conducting compressive strength by the types of specimens, fiber reinforced specimen with the highest compressive strength value at 28 days of age was cellulose fiber reinforced specimen as 280.4kgf/$\textrm{cm}^2$ and steel fiber specimen had the highest compressive strength of 250.7kgf/$\textrm{cm}^2$ at 180 days of age. In case of non-reinforced specimen, its compressive strength was 277.4kgf/$\textrm{cm}^2$ at 28 days of age and 273.1kgf/$\textrm{cm}^2$ at 180 days of age. Comparing the compressive strength of non-reinforced specimen to that fiber reinforced specimen showed that the compressive strength of fiber reinforced specimen was lower in the passage of age and the results of this experiment showed no effects of fiber reinforcement. As a result of testing reinforced concrete beam without shear reinforcement, ductility factors of specimens were 4.67 for non-reinforced specimen, 8.18 for steel fiber reinforced specimen, 6.20 for polypropylene fiber reinforced specimen and 5.49 for cellulose reinforced specimen, and it is found that steel fiber reinforced specimen was highest. When non-reinforced specimen and steel fiber reinforced specimen were compared, steel fiber reinforced specimen had higher ductility factor of about 75.2% than that of non-reinforced specimen.

• Tunnel and Underground Space
• /
• v.20 no.5
• /
• pp.369-377
• /
• 2010

Applied to the braced wall in order to stabilize the adjacent tunnel. A pre-load of bracing was imposed to prevent the horizontal displacement of the braced wall during the ground excavation. For this purpose, real scale model tests were conducted, without and with pre-load on braced wall. Real scale model tests were conducted, without and with building load (0 m, 1D, 2D) on ground surface. As a result, it was found that the stability of the existing tunnel adjacent to the braced wall could be greatly enhanced when the horizontal displacement of the braced wall was reduced by applying a pre-load, which was larger than the designated axial force of bracing. In this paper, the behaviors of braced wall and adjacent tunnel was studied. Model tests in 1:10 scale were performed in real construction sequences. Adjacent tunnel was 12 m in diameter and the size of test pit was 2.0 m (width) ${\times}$ 6.0 m (height) ${\times}$ 4.0 m (length) in dimension.