• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.2
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• pp.145-151
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• 2017

As an alternative to conventional explosive methods for demolition of concrete structures and rocks, the use of non-explosive demolition agents can be considered to reduce noise, vibration, and dust emissions during the demolition process. In this study, we conduct finite element analysis for crack initiation and propagation caused by the expansion of non-explosive demolition agents in square concrete structures. The predicted crack patterns are compared with the experimental results in the literature. The minimum values of the required expansion pressure of non-explosive demolition agents are also estimated, which depend upon the arrangement of non-explosive demolition agents and empty holes. Furthermore, we investigate the effect of empty holes on the fragmentation of concrete structures, and discuss the effective arrangement of non-explosive demolition agents and empty holes for fragmentation improvement.

• Wind and Structures
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• v.34 no.3
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• pp.275-290
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• 2022

Mobile sand barriers are a new type sand-retaining structure that can be moved and arranged according to the engineering demands of sand control. When only used for sand trapping, mobile sand barriers could be arranged in single row. For the dual purposes of sand trapping and sand stabilization, four rows of mobile sand barriers can be arranged in a staggered form. To reveal the effect of plane layout, the included angle between sand barrier direction and wind direction on the characteristics of flow fields and the sand control laws of mobile sand barriers, numerical computations and wind tunnel tests were conducted. The results showed that inflows deflected after passing through staggered arrangement sand barriers due to changes in included angle, and the sand barrier combination exerted successive wind resistance and group blocking effects. An analysis of wind resistance efficiency revealed that the effective protection length of staggered arrangement sand barriers approximately ranged from the sand barrier to 10H on the leeward side (H is sand barrier height), and that the effective protection length of single row sand barriers roughly ranged from 1H on the windward side to 20H on the leeward side. The distribution of sand deposit indicated that the sand interception increased with increasing included angle in staggered arrangement. The wind-breaking and sand-trapping effects were optimal when included angle between sand barrier direction and wind direction is 60°-90°.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.359-364
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• 2003

Population concentration phenomenon of city need large-scale ride, and ride is important urea that develop area and is armed surrounding land utilization. but, it is difficult to evaluate effect that ride gets land utilization change and community development as quantitative. Therefore, this research evaluates change and effect of land utilization as political to subway station that is main ride of Seoul City, and chose standard and position for right place arrangement of electric railway station. Research contents analyzed subway station effect area interior and external land utilization change taking advantage of GIS's buffer function and RS's classification technique, and decide precedence at subway station establishment and chose position of subway station for effect area outside area.

• Journal of Korea Trade
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• v.23 no.3
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• pp.52-67
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• 2019

Purpose - This study analyzes the effect of the authorized economic operator-mutual recognition arrangement (AEO-MRA) on the performance of Korean exporters and importers. The effect of the import-export companies' characteristics, such as annual sales, the number of foreign markets, and overseas experience, on the AEO-MRA is deduced; the relationship between this effect and firm performance is analyzed. Design/methodology - An empirical research model was constructed and analyzed using structural equation modeling. The effect of AEO-MRA on logistics and operational performance was derived from the aforementioned characteristics as leading factors of the AEO-MRA. The regulatory influence of cooperation with logistics companies was analyzed in the AEO-MRA effect on logistics performance. Thus, 172 valid samples were obtained from import-export companies certified by the AEO-MRA. Findings - Among the aforementioned characteristics, only "annual sales" has a positive effect on the AEO-MRA, whose effect enhances logistics and operational performances. The AEO-MRA effect did not directly affect operational performance. Owing to the adjustment effect analysis, the AEO-MRA effect and logistics performance relationship is strengthened if the cooperative relationship with the logistics company is higher than a certain level. If this cooperation falls below a certain level, the AEO-MRA effect on logistics performance reduces. Thus, logistics cooperation is an important factor in the AEO-MRA effect and logistics performance relationship. Originality/value - Hinging on the resource-based theory and relational viewpoint, an empirical model that explains the relationship between the AEO-MRA effect and firm performance is established.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.228-228
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• 2004

Nuclear Environment Technology Institute (KHNP-NETEC) developed the conceptual design of the low and intermediate-level radioactive waste (LILW) repository. Among many engineering challenges, it is of particular importance to find out an optimum arrangement of near-surface disposal vaults in the repository area to minimize the radionuclide flux and concentration at the interface between the geo-sphere and bio-sphere. (omitted)

• Journal of Korea Game Society
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• v.2 no.1
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• pp.84-91
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• 2002

The big difference of game scenario writers from ordinary scenario writers is the creativity of interactive game element. Game scenario writers should complete scenario form before making conti of game production, develop new item that is the essence of game and be able to write mulit-scenario for diverse story developments. Also, he should have the ability to advise on effective arrangement for sound effect to game designer.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.513-518
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• 2002

Prestressing tendons in the wall of circular storage tank were investigated from the viewpoint of equivalent load method. Special attention was paid to the effectiveness of eccentricities of the circumferential and vertical tendons. Some aspects which are frequently overlooked or misinterpreted in the analysis of vertical tendons are discussed. It is expected that the equivalent load method can be effectively used to simplify the analysis of tendons in the circular wall thus to minimize the errors.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.973-978
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• 2002

This study was performed to verify the effect of various testing conditions affecting measured compressive strength of concrete core and to compute the correction coefficients for it. Conditions of specimens affecting test results include size(diameter), height-diameter ratio, humidity of specimen, amount and arrangement of bar, core direction from structure and method of end preparation. In testing core strength of concrete, special cares should be taken on various testing conditions whose effects have been latent in conventional concrete.

• Progress in Superconductivity and Cryogenics
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• v.2 no.1
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• pp.40-44
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• 2000

The round HTS wire is easier to handle than the rectangular HTS tape. This paper describes the coupling losses of the round HTS wires by finite element method. Effect of the round HTS wire are considered. Two types of Filaments arrangement, stacked filament and radial filaments, are considered. Calculation results show that coupling losses of the round HTS wire vary only a little with the direction of external magnetic field.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.181-182
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• 2003

Poly(vinyl alcohol) (PVA) is a semicrystalline polymer whose hydroxyl groups produce inter-and intramolecular hydrogen bonding. The extent of hydrogen bonding is greatly affected by stereoregularity of hydroxyl groups, so-called tacticity, of PVA[1-3]. Hydrogen bonding has a profound effect on the rheological and mechanical properties of the polymer, which is largely determined by the density and spatial arrangement of hydroxyl groups. (omitted)