• Fire Science and Engineering
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• v.22 no.2
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• pp.49-56
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• 2008

Smoke propagation for the Daegu Metro fire is reproduced by a reduced-scale model experiment. The three-story station building was modeled with 1/20-scale, and the tunnel connected to the platform was not completely modeled because of its length. To include the flow resistance the tunnel provides the mesh screens were used in the model. The fire scenario was selected based on the fire growth rate of the metro car seat where the fire initiated. The time when smoke arrived at each compartment in the station building was measured by thermocouples and visualization. Regarding fire ventilation, the air supply that has been accepted as conventional design in a subway metro building intensifies smoke spread. The results show that the whole building was filled with smoke in about 10 minutes in case of no ventilation.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.393-398
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• 2008

The environment is the important resource to use as well as to conserve for the development. Since 1990s, it has accentuated the importance of the environment and tried to conserve the environment in many areas. Among many area, the building industry has played a role to destruct the environment for providing the living decent space and brought the environmental affect. Therefore, the building industry should endeavor to mitigate the environmental affect. In building life cycle, it consumes the energy and natural resources. But it is difficult to evaluate the environmental affect during the whole building life. It is impossible to calculate the environmental affect without the much time and effort. Therefore. it requires the easy and handing program to calculate the affect to environment in each building life cycle. Until now, many program for assessing the affect to the environment have been developed and limitedly used because of the assessment scope and contents. In this paper, it aimed at developing the assessment program of LCA, focused on the energy consumption and carbon-dioxide emission compared with the domestic and foreign concerned programs. The developed program is divided into 3 areas; construction, maintenance, demolition.

• Journal of the Korean Institute of Educational Facilities
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• v.20 no.3
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• pp.41-52
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• 2013

In the current condition of seeking eco-friendly development, Green Building Certification Criteria can reduce environment burden that is able to be arose in life cycles of buildings. Moreover, it is a great help to induce to constructing pleasant environment. The ripple effect that also improves saving of energy and resources of the whole country, and green-house gases reduction effect and environment friendliness of other buildings can be expected by promoting eco-friendly education facilities which accounts for a great part of public buildings in comparison with other buildings. In this study, analysis of old and new indicators' contrast and contents in Green Building Certification, and post evaluation of education facilities and interviews on authorities were proceeded for improving evaluation indicator of each item in Green Building Certification Criteria. As a result, it analyzed problems in terms of institution and operations management, and drew implications accordingly. In addition, it has a significance in that it proposes improvements of substantively applicable indicators with high applicability.

• Smart Structures and Systems
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• v.23 no.3
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• pp.295-306
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• 2019

Shanghai Tower is a 632-meter super high-rise building located in an area with wind and active earthquake. A sophisticated structural health monitoring (SHM) system consisting of more than 400 sensors has been built to carry out a long-term monitoring for its operational safety. In this paper, a reduced-order model including 31 elements was generated from a full model of this super tall building. An iterative regularized matrix method was proposed to tune the system parameters, making the dynamic characteristic of the reduced-order model be consistent with those in the full model. The updating reduced-order model can be regarded as a benchmark model for further analysis. A long-term monitoring for structural dynamic characteristics of Shanghai Tower under different construction stages was also investigated. The identified results, including natural frequency and damping ratio, were discussed. Based on the data collected from the SHM system, the dynamic characteristics of the whole structure was investigated. Compared with the result of the finite element model, a good agreement can be observed. The result provides a valuable reference for examining the evolution of future dynamic characteristics of this super tall building.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.363-374
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• 2018

The façade is an important, complex, and costly part of a building, performing multiple objectives of value to the occupants, like protecting from wind, rain, sunlight, heat, cold, and sound. But the frequency of façade fires in large buildings is alarming, and has multiplied by seven times worldwide over the last three decades, to a current rate of 4.8 fires per year. High-performing polymer based materials allow for a significant improvement across several objectives of a facade (e.g., thermal insulation, weight, and construction time) thereby increasing the quality of a building. However, all polymers are flammable to some degree. If this safety problem is to be tackled effectively, then it is essential to understand how different materials, and the façade as a whole, perform in the event of a fire. This paper discusses the drivers for flammability in facades, the interaction of facade materials, and current gaps in knowledge. In doing so, it aims to provide an introduction to the field of façade fires, and to show that because of the drive for thermal efficiency and sustainability, façade systems have become more complex over time, and they have also become more flammable. We discuss the importance of quantifying the flammability of different façade systems, but highlight that it is currently impossible to do so, which hinders research progress. We finish by putting forward an integral framework of design that uses multi-objective optimization to ensure that flammability is minimized while considering other objectives, such as maximizing thermal performance or minimizing weight.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.3
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• pp.341-348
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• 2020

The ability to extract useful information from an image, such as the human eye, is an interface technology essential for AI computer implementation. The building recognition technology has a lower recognition rate than other image recognition technologies due to the various building shapes, the ambient noise images according to the season, and the distortion by angle and distance. The computer vision based building recognition algorithms presented so far has limitations in discernment and expandability due to manual definition of building characteristics. This paper introduces the deep learning CNN (Convolutional Neural Network) model, and proposes new method to improve the recognition rate even by changes of building images caused by season, illumination, angle and perspective. This paper introduces the partial images that characterize the building, such as windows or wall images, and executes the training with whole building images. Experimental results show that the building recognition rate is improved by about 14% compared to the general CNN model.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.51-55
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• 2004

Generally, aggregate may limit the strength of concrete, and aggregate with undesirable properties including strength, shape and grading etc. cannot produce good concrete. Also, the properties of aggregate greatly affect the durability and structural performance of concrete. Recently, it has increased the using of crushed aggregate for concrete due to the exhaustion of good natural aggregate. In case of Korea, the using ratio of crushed stone occupies about 97％ of whole coarse aggregate, and ratio of crushed sand occupies about 18.3％ of whole fine aggregate. This is an experimental study to compare and analyze the properties of crushed sand for concrete in capital region and concrete according to the replacement ratio of crushed sand to do suitable mix design and improve the concrete quality. According to results, it was found that nearly all the properties of crushed sand satisfied with the value recommended by KS.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.2
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• pp.9-21
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• 2011

This study aims to examine and research the characteristics of apartment landscape at the street from a view that apartments are the major element of a cityscape and many apartments form a street today. Then, the subjects of this study were three sections consisting of streets in Namak New Town and the results were as follows. A streetscape is necessary to have identity under the unity(context) of parts which orient to "one as a whole". However, the subject apartments were not united(contextual) in layouts, roofs, and walls, whereas their facades appeared too united(contextual). Accordingly, to make a united(contextual) streetscape, the wall located in a boundary(a buffer zone) with public space which consists of a streetscape, building layout, building height, and roof forms need a design guideline which can have unity as a whole to connect with architectural design. On the other hand, the facade which was found too uniform should have a more active design guideline to elicit identity at unity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3780-3797
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• 2022

The estimation of radio map (RM) is a fundamental and critical task for the network planning and optimization performance of mobile communication. In this paper, a RM estimation method is proposed based on a deep dual learning structure. This method can simultaneously and accurately reconstruct the urban building map (UBM) and estimate the RM of the whole cell by only part of the measured reference signal receiving power (RSRP). Our proposed method implements UBM reconstruction task and RM estimation task by constructing a dual U-Net-based structure, which is named RadioCycle. RadioCycle jointly trains two symmetric generators of the dual structure. Further, to solve the problem of interference negative transfer in generators trained jointly for two different tasks, RadioCycle introduces a dynamic weighted averaging method to dynamically balance the learning rate of these two generators in the joint training. Eventually, the experiments demonstrate that on the UBM reconstruction task, RadioCycle achieves an F1 score of 0.950, and on the RM estimation task, RadioCycle achieves a root mean square error of 0.069. Therefore, RadioCycle can estimate both the RM and the UBM in a cell with measured RSRP for only 20% of the whole cell.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.71-79
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• 2008

The rebar work is very related to the safety and durability of the building. Recently, the rebar work is produced some serious problems due to the lack of skillful crafts-man and the rising cost of rebar materials. Many papers have dealt with the rebar work of the manufacturing system in plants with a view to improvement those problems. But, the research on the rebar work of the manufacturing system in field is in a insignificant condition. This study presents the following improvement schemes as a result. First, the education strengthening for evaluation on practical affairs, second, the reinforcement of drawing & management in shop drawing and finally the simplification of apartment rebar work in slab. Also, this paper aims at advancing apartment rebar work by the actual condition survey in slab work. The further research will be needed about the whole structure parts such as foundation, wall, girder and rebar truss-deck plate as one of the improvement methods.