• Proceedings of the KSME Conference
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• 2001.11b
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• pp.254-259
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• 2001

This study deals with the use of the conjugate gradient method for the simultaneous estimation of two unknown boundary heat fluxes on the slab in reheating furnace. Temperature measurements by the experiment are used in the inverse analysis. The heat flux estimations for three different cases of measurement locations in the slab are performed: non-skid, skid, and shift-skid zones. The estimated heat fluxes for three cases indicated the three regions having local peak values of heat fluxes. The estimated temperatures at measurement locations were in good agreements with the measured temperatures within 5% relative error.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.333-340
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• 2006

In these days the floor vibration is beginning to make its appearance of the environmental dispute in apartment building. Standard floor system are suggested for the settlement of this issue by government. The sound of floor impact sound is needed to secure comfortable quality in housing. Also, it is required an accurate analysis and a proper evaluation for floor vibration. Refine model is necessary for the floor system of housing to analyze accurately the floor vibration. But this refine model is not efficient because it is required so much running time for vibration analysis and it is difficult of modeling of standard floor slab. In this paper, new modeling methods of standard floor slab are proposed for the accurate rigidity evaluation. By using the new modeling method, the accurate vibration response can be obtained and can accurately evaluate the rigidity of standard floor system with resilient materials. Therefore the proposed modeling method is of practical use for vibration analysis of floor system of apartment building.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.496-499
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• 2006

In this study, a practical method of shrinkage stress analysis on concrete slab in multi-story building is proposed, which considers both internal restraint and external restraint variation resulting from construction sequence. The shrinkage stress due to external restraint is obtained by multiplying relaxation coefficient to elastic shrinkage stress. The additional shrinkage stress due to internal restraint is obtained by residual strain of the elastic analysis. A verification example was analyzed and compared by the proposed method and commercial analysis program that is capable of time-dependent analysis of concrete. The results of 10-story example building show that the internal restraint of reinforcement increases the shrinkage stress considerably at the slabs under loose external restraint.

• Steel and Composite Structures
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• v.25 no.5
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• pp.523-534
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• 2017

Cable-supported ribbed beam composite slab structure (CBS) is proposed in this study. As a new cable-supported structure, it has many merits such as long span availability and cost-saving. Inspired by the previous research on cable-supported structures, the fabrication and construction process are developed. Pre-stress design method based on static equilibrium analysis is presented. In the algorithm, the iteration convergence can be accelerated and the calculation result can be kept in an acceptable precision by setting a rational threshold value. The accuracy of this method is also verified by experimental study on a 1:5 scaled model. Further, important parameters affecting the mechanical features of the CBS are discussed. The results indicate that the increases of sag-span ratio, depth of the ribbed beam and cable diameter can improve the mechanical behavior of the CBS by some extent, but the influence of strut sections on mechanical behavior of the CBS is negligible.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.627-632
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• 2016

In this paper, we propose a new vision-based defect inspection system for the surface of hot slabs. To minimize the influence of self-emission from slab surfaces with high temperature, an optic method based on blue LED light and a blue pass filter is proposed. Because the slab surface is partially covered with scales, which are unavoidable oxidized substances caused during manufacturing, it is difficult to distinguish between vertical cracks and scale. In order to resolve this problem and to improve the detection performance, the use of a Gabor filter and dynamic programming are proposed. Finally, the effectiveness of the proposed method is shown by means of experiments conducted on images of hot slabs that were obtained from an actual slab production line.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.219-223
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• 2000

The evaluation of habitability to building vibration is conducted by the values of natural frequency, amplitude displacement, damping ratio. These values can be obtained from test or analytical results. Data acquisition through test may be possible in existing building, however, to estimate the serviceability of the building, it is necessary to evaluate those values at the stage of design. The natural frequency is important and basic factor for the evaluation of the serviceability. Calculation method of the effective stiffness in RC slab is proposed. To prove the efficiency of the proposed method, sample results of the analysis and the test are compared. These results proved that the effective width proposed to calculate the effective stiffness is proper to evaluate the natural frequency.

• Structural Engineering and Mechanics
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• v.62 no.4
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• pp.477-485
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• 2017

The structural designs of RC flat plates that have no flexural stiffness by boundary beams may be governed not by strength conditions but by serviceabilities. Specially, since over-loading and tensile cracking in early-aged slabs significantly increase the short- and long-term deflections of a flat plate system, a construction sequence and its impact on the slab deflections may be decisive factors in designs of flat plate systems. In this study, the procedure of simulating slab deflections with considering construction sequences, concrete cracking, and long-term effects is proposed. The proposed method is practically useful, as it can predict well the slab deflections at construction and service stages only with a few input data. The proposed method is verified by comparisons with measured results in a real-scale test.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.465-468
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• 2004

The first thing in remodelling of an apartment is the enlargement of living area, which is usually attained through extending balcony or corridor to the outside of the building. As a reasonable solution to the extension of floor a method of rigid connection in which steel bars are injected into the existing slab and concrete of newly building slab is installed with proper reinforcement is proposed in this research. To verify the structural performance of the method bending tests have been carried out for seven slab specimens.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.337-340
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• 2006

The purpose of this study is to propose the stiffness reduction factor for flat plate slabs under lateral loads. Current design code (e.g., ACI 318-05) requires considering the effects of cracks for calculating slab stiffness under lateral loads. This study collected the test results of 20 interior slab-column connections, from which stiffness reduction in each test was estimated with respect to the ratio of applied moment to cracking moment ($M_a/M_{cr}$). Based on collected data, this study proposed equations for calculating stiffness reduction with respect to $M_a/M_{cr}$. To verify the proposed equations, this study conducted the experimental test of interior slab-column connections under quasi-static cyclic loading. From the test, load-deformation curve is compared to that obtained from effective beam width method with the proposed equation for the stiffness reduction. It is shown that the effective beam width method with the proposed equation for stiffness reduction predicts accurately the test results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.77-81
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• 1999

The predictions of metal flow forging load optimal die angle and preform size are not so easy in turbine blade forging. First of all the quality of final product is influenced by side force which is one of the significant factors. in this study slab method is applied to determine optimal die angle minimizing side force and the position of preform Finally drawing of die design is obtained in optimal die angle with developing tool that is composed of Visual Basic.