• Wind and Structures
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• v.38 no.3
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• pp.203-214
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• 2024

Large-span cantilevered roof represents a unique type of structure that is vulnerable to wind loads. Inspired by the need to maximumly reducing the rooftop wind loads, this study examined the feasibility of positioning vented slots on the leading edge, and the effectiveness of such aerodynamic mitigation measures are assessed via both physical and numerical simulations. The reliability of numerical simulation was evaluated via comparisons with the wind tunnel tests. The results indicated that, the variation of venting hole arrangement can cause significant change in the rooftop wind load characteristics. For the cases involved in this study, the maximum reduction of mean and peak wind suction coefficients are found to be 9% and 8% as compared to the original circular slot without venting holes. In addition, the effect of slot shape is also evident. It was shown that the triangular shaped slot tends to increase the wind suction near the leading edge, whereas the hexagonal and octagonal shaped slots are found to decrease the wind suction. In particular, with the installation of octagonal shaped slot, the maximum reduction of wind suction coefficients near the leading edge reaches up to 31% as compared to the circular shaped slot, while the maximum reduction of mean wind suction coefficients is about 30%.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.177-184
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• 2003

The purposes of this study are to develop the real coding genetic algorithm and to obtain the shape optimization of a cable domes by using this scheme. Generally, the structural performance of the cable dome is influenced very sensitively by prestress, geometry and length of the mast because of flexible structures. So, it is very important to decide the optimum shape to get maximum stiffness of cable domes. We use the two models to verify the usefulness of this algorithm for shape optimization and analyze the roof system of Seoul olympic gymnastic arena as one analytical model of practical structures

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.35.5-35
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• 2001

The purpose of the study is to develop a synthetic method for generating arbitrary number of not the same but similar texture images. The method includes processes to extract basic shape elements from texture images originating in actual objects, to select them to reappear the image features and to arrange them in a image plane. The authors have already proposed the shape-pass type filter bank assuming that the sensual impression mainly depends on minute shapes existing in the texture images. By use of nine basic shape elements, namely black/white-roof, black/white-line, black/white-snake, black/white-pepper, and cliff, natural texture images originating in actual objects have been characterized by feature vectors in a nine dimensional space. To generate arbitrary number of similar texture images, minute shape pieces ...

• Conservation Science in Museum
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• v.4
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• pp.17-21
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• 2003

We performed conservation treatment for the sarira reliquary from the pagoda of Hwangnyongsa temple site. The sarira reliquary is in the shape of gilt-bronze octagonal miniature pagoda. Through radiography, it was newly proved that a radial design exists on the roof part. The gilded layer was plated with amalgam. Each part was plated first before being put together. We restored the lost parts and made supports, and then assembled it in the following order: base, upper part of the base, shaft and roof part.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.124-125
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• 2013

The purpose of this research is to propose an approximate estimation system for Modernized Hanok. Mock-up (Jisinjae) site data has been collected and analysed to characterize the modernized Hanok and to examine the range of cost fluctuation rate with each work items. As a result, number of floor, area (㎥), shape, methods and materials were considered as key factors for price change on the total construction cost. Furthermore, wood structure (34%) and roof (17%) account for major cost percentage. The cost fluctuation rate of two factors were -3.3%~+5.6% (wood structure) and -4.1%~+4.2% (roof). For further research, existing method will be analysed in order to developing the Hanok estimation system. And the cost fluctuation rate of every work items will be continually evaluated.

• Structural Engineering and Mechanics
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• v.86 no.2
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• pp.157-165
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• 2023

In the present work, the vibration characteristics of sandwich nanocomposite shells, fortified with graphene platelets (GPLs) have been researched. The shell has been considered as the stadium roof shape with double curvatures under vibration due to earthquake. The nanocomposite has the matrix of concrete which is fortified with uniform or linear dispersions of GPLs. Also, the core possesses cellular type square architecture for which the effective elastic modulus has been defined in the context of relative density based relations. Based upon the classic shell strains containing two identical curvatures, the governing equations have been established and solved through differential quadrature approach. It will be seen that the vibrational frequencies rely on the core relative density, height of layers, the amount and dispersions of GPLs and even shell geometric parameters.

• Journal of the Korean Geosynthetics Society
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• v.9 no.4
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• pp.9-15
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• 2010

In this study, a non-open cut method using a round or square pipe which has been commonly employed in Korea was experimentally evaluated and the behavioral features resulting from the friction while the pipe is penetrated into the ground was identified through the scale model test. To that end, a test device was fabricated by type of penetration pipe, by which the surface displacement caused by surrounding friction resistance was monitored. To simulate the settlement and heaving by excavation stage, the test was conducted based on generalized friction condition and surface displacement and the result therof was compared and analyzed, considering the type of penetration pipe.

• Journal of Korean Association for Spatial Structures
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• v.16 no.3
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• pp.47-58
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• 2016

Cable network system is a flexible lightweight structure which curved cables can transmit only tensile forces. The weight of cable roof dramatically can reduce when the length becomes large. The cable network system is too flexible, most cable systems are stabilized by pretension forces. The tensile force of cable system is greatly influenced by the sag ratio and pretension forces. Determining initial sag ratio of cable roof system is essential in a design process of cable structures. Final sag ratio and pretension depends on initial installed sag and on proper handling during installation. The design shape of cable system has an affect on the sag and pretension, and must be determined using well-defined design philosophy. This paper is carried out the comparative data of the deflection and tensile forces on the geometric non-linear analysis of cable network systems according to sag ratio. The study of cable network system is provided to technical informations for the design of a large span cable roof, analytical results are compared with the results of other researchers. Structural nonlinear analysis of systems having cable elements is relatively complex than other rigid structural systems because displacements are large as a reason of flexibility, initial prestress is applied to cables in order to increase the rigidity, and then divergence of nonlinear analysis occurs rather frequently. Therefore, cable network systems do not exhibit a typical nonlinear behavior, iterative method that can handle geometric nonlinearities are necessary.

• Structural Engineering and Mechanics
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• v.33 no.4
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• pp.503-527
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• 2009

This paper presents experimental results on the behaviour and ultimate load of fifteen pipes and six roof panels made of ferrocement. Additional results from three roof panels, carried out by others, are also compared with this research results. OPC cement, natural sand and galvanised iron wire mesh were used for the construction of 20 mm thick specimens. The pipe length was 2 m and roof panel length was 2.1 m. The main variables studied were the number of wire mesh layers which were 1, 2, 3, 4 and 6 layers, the inner pipe diameter which were 105, 210 and 315 mm, cross sectional shape of the panel which were channel and box sections and the depth of the edge beam which were 95 mm and 50 mm. All specimens were simply supported and tested for pure bending with test span of 600 mm at mid-span. Tests revealed that increasing the number of wire mesh layers increases the flexural strength and stiffness. Increasing the pipe diameter or depth of edge beam of the panel increases the cracking and ultimate moments. The change in the pipe diameter led to larger effect on ultimate moment than the effect of change in the number of wire mesh layers. The box section showed behaviour and strength similar to that of the channel with same depth and number of wire mesh layers.

• Analytical Science and Technology
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• v.14 no.6
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• pp.476-485
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• 2001

Both concave and convex roof-end tiles having same style and shape are excavated in Yongjangsung castle at Jindo and Burnhwasa temple at Wando in Jeollanam-Do that are the Sambyulcho's resistance sites against Mongolia in the late Koryo dynasty. Obtained data by NAA have been used to classify the equality of a raw materials' porvenance by multiple correlation analysis(MCA) and discriminant analysis. The results of MCA has shown that there are very high correlation for [La : Sm], and [Lu : Yb]. Exactly pottery site at Chungdo, roof tile site at Chungyang, Yongjangsung castle and Bumhwasa temple and Chunghaejin site at Jangdo were distributed for four trace elements, Cr, Sc, ${\Delta}$(${\Sigma}$(Lu, Yb)) and Eu by discriminant analysis, and their accuracy is above 95%. This means that Yongjangsung castle and Bumhwasa temple have same raw material's provenance.