• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.113-117
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• 2004

We need the contingency cost in order to deal with the uncertainty to be accompanied inevitably at the construction and an every kind risk not to forecast in advance. And also the contingency colt needed for the change order and we need it for reduction of the delay and reduce the trouble between owner and constructor. This study, through checking and analyzing the risk factor, in the step of domestic construction, suggests optimal management reserve to specific business about the contract type and the scale. The main results of this research are summarized as follow. First, I investigated the recognition about the contingency cost, grasped the risk to be happened at the construction step and found out the frequency occurrence, through making up question to engineer are carrying out their job in the domestic construction. Second, I computed optimal contingency cost rate by the statistics investigation, and proposed an improvement plan and problem when compute a contingency cost.

• Journal of the Korean Institute of Rural Architecture
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• v.11 no.1
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• pp.37-45
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• 2009

This study aims for proposing improvement method for streetscape in a small and medium city of Korea. According to this purpose, in chapter 2, by inspecting conservation of street environment and streetscape, deduce the frame for analyzing streetscape in commercial district. In chapter 3, analyzing present condition and problems of selected streets in Pohang City, derive the primary factors to induce desirable streetscape through problems and their reason between the analyzed elements of building form. Analyzed elements are composed of floor elements, wall elements, ceiling elements. The detailed elements are pavement of road, street furniture, height of buildings, color and material of building and outdoor advertisements. In chapter 4, by conducting a questionnaire survey of pedestrians about street images -choosing impressive physical elements and the feeling of the street by the list of adjective of semantic differential scale- and the preference, propose the direction of improvement about streetscape in commercial district.

• Architectural research
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• v.7 no.1
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• pp.19-26
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• 2005

Unlike other countries, Korea uses various kinds of wall-paper as finishing material. Conventional wall-paper consists of paper and vinyl, and petrochemical ink is used for the decoration of the surface. Adhesive is used to paste the wall with the wall-paper, which emit substantial amounts of VOCs and formaldehyde. In this study, VOCs characteristics emitted from specimens made of concrete, mortar, gypsum board and wall-paper were investigated using small chamber method. Moreover, concentration and emission factor of BTEX(Benzene, Toluene, Ethylbenzene, m,p,o-Xylene) and TVOC were investigated, and concentration and emission factor decay were estimated. As a result of the prediction, both time-dependent concentration decay and cumulative concentration can be converted into the logarithmic scale. Furthermore, prediction equations were developed from the experimental results under accurately controlled experimental conditions. Therefore, there may be difference if the estimated equations are directly applied to real buildings. Further research should be done on the generalization of the developed prediction equations.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.119-124
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• 2014

Recently buildings are constructed in larger and higher scales and becoming more complex. However from small to large scale buildings and on construction sites there still are fire safety accidents that occur continuously. Therefore this study is aimed to assess of evacuation safety for building construction by use of simulation. On this study, the evacuation times required were estimated for the permissible evacuation times in cases. Fire safety management plans were suggested for building construction.

• Journal of the Korean housing association
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• v.17 no.1
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• pp.67-75
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• 2006

Multi-family housings caused several problems related to physical form such as isolation of housing estate, inhumanity of the exterior space, and mismatch with the urban structure. To handle these problems, the purpose of this study is to analyse density elements which have a direct impact on physical forms, thereby understand the characteristics of physical form and also identify a meaning of inter-relationships between them. Therefore both formal constituents and density elements are reformed into respective analyzing indices. From the analysis, physical form and the spatial layout of buildings were more uniform in large-scale housing estates than in medium or small housing estates. However, small-scale housing estates showed various form and the spatial layout of buildings in order to increase the building density.

• Structural Engineering and Mechanics
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• v.17 no.1
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• pp.69-85
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• 2004

The novel form of composite walling system consists of two skins of profiled steel sheeting with an in-fill of concrete. Such walling system can be used as shear elements in steel framed building subjected to lateral load. This paper presents the results of small-scale model tests on composite wall and its components manufactured from very thin sheeting and micro-concrete tested under monotonic and cyclic shear loading conditions. The heavily instrumented small-scale tests provided information on the load-deformation response, strength, stiffness, strain condition, sheet-concrete interaction and failure modes. Analytical models for shear strength and stiffness are derived with some modification factor to take into account the effect of quasi-static cycling loading. The performance of design equations is validated through experimental results.

• Journal of the Korean Institute of Educational Facilities
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• v.1 no.2
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• pp.33-46
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• 1994

This paper inquires into the most desirable measures which can diversify instruction-learning methodsand take advantage of educational facilities in order to carry out both education for the whole man and individualized instruction in a smallscale class primary school. For this purpose, this paper makes investigation into thirty primary schools at Pochon district(including one branch school) and analyzes the contents of investigation into as follows: 1) the general present status of primary schools at Pochon district educational facilities, 2) the educational environment and educational facilities, 3) the instructional systems design and instructional media, 4) the educational facilities for the scale of applying instructional media. And then, on the side of educational facilities, This paper makes proposal for eight accessible alternatives which diversify instruction learning methods and enforce individualized instruction (=open education) without expanding or reconstructing on alarge scale a building of the existing small-scaleprimary schools.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.647-656
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• 2019

This paper aims to analyze the priority of elements in building management system surveying owners living in Small-scale Apartment, and to suggest basic data for establishing effective management alternatives. To achieve the goal, this paper extracted the elements from a guideline supported by the Ministry of Land, Infrastructure and Transport in Korea, and tried to analyze their priority. The result as follows. First, the analysis of the first level suggested that people give priority to facility management, moving management, security management and administrative for management. Second, on the analysis of the second level, settlement of budget was the most important for the administrative, cleaning for facility management, parking management for security management and advertisement of the administrative for moving management. By suggesting the result, this paper concludes that it would be very important to establish a regional management corporation to manage the Small-scale Apartment.

• Wind and Structures
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• v.32 no.4
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• pp.371-391
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• 2021

Tornadoes are the most devastating meteorological natural hazards. Many empirical and theoretical numerical models of tornado vortex have been proposed, because it is difficult to carry out direct measurements of tornado velocity components. However, most of existing numerical models fail to explain the physical structure of tornado vortices. The present paper proposes a new empirical numerical model for a tornado vortex, and its load effects on a low-rise and a tall building are calculated and compared with those for existing numerical models. The velocity components of the proposed model show clear variations with radius and height, showing good agreement with the results of field measurements, wind tunnel experiments and computational fluid dynamics. Normal stresses in the columns of a low-rise building obtained from the proposed model show intermediate values when compared with those obtained from existing numerical models. Local forces on a tall building show clear variation with height and the largest local forces show similar values to most existing numerical models. Local forces increase with increasing turbulence intensity and are found to depend mainly on reference velocity Uref and moving velocity Umov. However, they collapse to one curve for the same normalized velocity Uref / Umov. The effects of reference radius and reference height are found to be small. Resultant fluctuating force of generalized forces obtained from the modified Rankine model is considered to be larger than those obtained from the proposed model. Fluctuating force increases as the integral length scale increases for the modified Rankine model, while they remain almost constant regardless of the integral length scale for the proposed model.

• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.553-556
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• 2004

We present a new model for the generation of magnetic fields on large scales occurring at the end of cosmological reionisation. The inhomogeneous radiation provided by luminous sources and the fluctuations in the matter density field are the major ingredients of the model. More specifically, differential radiation pressure acting on ions and electrons gives rise to electric currents which induce magnetic fields on large scales. We show that on protogalactic scales, this process is highly efficient, leading to magnetic field amplitudes of the order of $10^{-1l}$ Gauss. While remaining of negligible dynamical impact, those amplitudes are million times higher than those obtained in usual astrophysical magnetogenesis models. Finally, we derive the relation between the power spectrum of the generated field and the one of the matter density fluctuations. We show in particular that magnetic fields are preferably created on large (galactic or cluster) scales. Small scale magnetic fields are strongly disfavoured, which further makes the process we propose an ideal candidate to explain the origin of magnetic fields in large scale structures.