• Architectural research
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• v.25 no.2
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• pp.29-40
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• 2023

The purpose of this study is to analyze the conflicts caused by the spatial expansion in two types of urban heritage in Seoul. To explain the national and professional orientation found in each spatial transformation, the study brought the concept of 'historic state' and 'epitome,' thereby examining the operating system of the conflicts. Field observations and stakeholder interviews were performed based on literature and historical research. The study results are as follows. ①In the case of Gwanghwamun and Donuimun, the spatial expansion is to find the historic state of the sites. Gwanghwamun with high national status and substance, conflicts show a pattern that spreads to memory conflicts. Donuimun is relatively unknown and has no substance so that a flexible method of digital restoration was applied. ② In the case of Ikseon-dong and Bukchon hanok, they show heterogeneous spatial expansion. The conflicts in relation to this is caused by the epitome of hanok. In Ikseon-dong, illegal installation of structures(non-epitome) is prevalent, while in Bukchon, there was a process of transferring the new basement(non-epitome) as part of the hanok. ③Conflicts in Gwanghwamun can be coordinated by referring to the digital restoration of Donuimun, and conflicts in Ikseon-dong can be resolved by taking Bukchon as a precedent.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.225-226
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• 2000

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.77-77
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• 2003

• Journal of the Korean Geotechnical Society
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• v.37 no.2
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• pp.19-31
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• 2021

Micropiles are cast-in-place piles with small diameters. The advantage of micropile is low construction expense and simple procedures, so it is widely applied to existing buildings and structures for the reinforcement of foundation and seismic performances. The base expansion structure has been developed following the original mechanism of horizontal expansion steps under compressive loading. This kind of structure can be installed at the pile end to improve the bearing capacity by tip area enlargement and horizontal force increment to the pile surface area. However, 'Micropile with base expansion structure' cannot be put into practical use, because detailed verification for the developed technique has not been conducted so far. In this research, 3-D numerical analysis was conducted to figure out the bearing mechanism of base expansion micropile and to verify the bearing capacity improvement compared to the general micropiles. 3-D modelling of micropile with base expansion structure was carried out and input parameter was determined. Bearing mechanism induced by base expansion structure was analyzed by lab-scale modelling, and bearing capacity improvement was verified by field-scale analysis.

• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.35-42
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• 2017

In this study, to quantitatively evaluate the strength characteristics of the inflatable liquid used for the recovery of soft ground or partial settlement, the inflatable liquids were prepared by dividing the inflatable capacity and the strength characteristics were analyzed according to the conditions. The experimental group was divided into two groups: relatively high expansion group and low expansion group. The specimens were prepared by controlling the volume of 10 ~ 30% of the maximum expansion volume, and the strength of the specimens were evaluated. The compressive strength of the high expansion group and low expansion group was about 2.1 times.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.1 s.113
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• pp.54-61
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• 2006

Basically corrugated board is composed of three layers of different basis weight and stock composition. Warp is well-known for one of the most important problems of corrugated board production. Warp is caused by difference of hygro-expansibility of linears between top and bottom. This research was performed to evaluate the effect of paper properties on the warp of corrugated board. To evaluate warp, dynamic expansion properties of paper was tested using DPM(dynamic penetration measuring system). The effects of sizing, stock composition and wet-pressing on dynamic expansion properties were also evaluated. Commercial base papers showed different dynamic expansion property depending on stock composition and papermaking operation. Sizing treatment decreased and wet-pressing increased the amount of dynamic expansion. To reduce warp of corrugated board, management of dynamic expansion of base papers should be controlled by manipulating moisture, heat and tension, using a variety of adjustments available on the corrugator.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.85-88
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• 2008

As super-high-strength concrete uses a large amount of binder, there is an autogenous shrinkage strain larger than dry shrinkage and it degrades the quality of structures. Thus, we need a technology to minimize the shrinkage strain of super-high-strength concrete. Accordingly, the present study prepared super-high-strength concrete with design strength of over 100MPa and, using an embedded gauge, measured the shrinkage strain of free shrinkage specimens for super-high-strength concrete containing expansion agent. According to the results of this study, the expansion rate of concrete increased in the early stage due to the admixture of expansion agent, but the shrinkage rate went down with the lapse of time. The effect of the admixture of expansion agent on compressive strength appeared insignificant. Further research shall be made on different kinds of expansion agents and various mixture ratios for basic analysis to reduce autogenous shrinkage of super-high-strength concrete.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.468-479
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• 2012

In this paper, by a simple example it is shown that existing market-based criteria alone cannot completely and correctly evaluate the transmission network expansion from market view. However criteria congestion cost (CC) and social welfare (SW) together are able to correctly evaluate transmission network from market view and so they are adopted for the market-based transmission expansion planning. To simply indicate the limits of CC and SW social welfare percentage (SWP) and congestion cost percentage (CCP) are defined. To consider uncertainty in bids of market producers and consumers, and also indeterminacy in the acceptable boundaries of the SWP and CCP and their priorities, fuzzy assessment approach is used. In this approach, appropriate fuzzy sets and a fuzzy rule base are provided to evaluate the acceptability of an expansion plan. Then, the least-investment cost plan, which is acceptable in all probable scenarios, is searched. The proposed method is applied to an 8-bus system.

• Architectural research
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• v.9 no.1
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• pp.19-30
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• 2007

This study explores the issue of campus expansion of an urban university using an in-depth case study of New York University in New York City, USA. It investigates the physical pattern and development mechanism of the campus expansion process on a city grid structure. The three elements that characterize NYU's recent campus expansion, are (1) the university's commitment to building a student community around a public open space on a subway network, (2) four types of property acquisition and building development practiced by the university with private developers for space leasing, building renovation and development under changing local development circumstances, and (3) the city's initiative for attracting the private sector whose development activities influence the university's development dynamics. These findings suggest that the expansion planning of an urban university, due to its location in a city, should be placed on a local planning agenda, which can positively contribute to public goals through the collaborative engagement of the private and public sectors.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.184-190
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• 2019

To improve resistance in thermal shock of zirconia setter which is frequently and repeatedly exposed to high temperature, high degree of porosity and control of thermal expansion are needed for which the fused CSZ (CaO stabilized zirconia) is used to produce the zirconia setter. In the present study, the effects of sintering temperature, cool down condition, addition of CaO stabilizer, and addition of other additives on phase transition and thermal expansion behavior of the fabrication process of zirconia setter, were examined. The zirconia setter, fabricated with fused CSZ at 1550℃, exhibited 20.4 MPa of flexural strength, 6.8% of absorbance, and 27.9% of apparent porosity. The rapid change in thermal expansion of zirconia setter is observed at temperature around 800℃, and it was reduced by low firing temperature, slowed cooled down, and addition of CaO.