• 콘크리트학회논문집
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• 제19권1호
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• pp.39-46
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• 2007

본 연구에서는 최근 국내에서 신기술 등으로 인증되어 활용되고 있는 보수재료 공법을 적용한 폭로시험체를 제작한 후, 해양환경 및 일반 대기환경 하에서 장기폭로실험에 의한 정량적 폭로실험 데이터를 확보함으로서 향후 성능저하된 철근콘크리트 구조물의 보수재료 공법 성능평가 방법 및 품질관리기준 확립을 위한 기초 자료를 제시하고자 하였다. 해양 및 일반 대기환경 하에서 폭로재령 30개월까지 폭로실험을 실시한 결과 탄산화 및 염화물이온 침투 깊이는 피복두께에 비해 매우 적게 침투하였으며, 철근의 부식 면적과 부식 속도 결과를 토대로 폭로재령 30개월까지 철근 부식의 주된 원인은 내재 염화물량 및 매크로셀에 의한 부식이 가장 큰 원인으로 판단된다. 향후 폭로시험체의 지속적인 평가를 통하여 정량적인 폭로실험 데이터를 확보함으로서 보수재료 공법 성능 평가 방법 및 품질 관리 기준 확립을 위한 기초 자료를 제시할 수 있을 것으로 판단된다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.242-249
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• 2009

High-rise construction sites, especially those situated in spatially constrained urban areas, have difficulties in timely delivery of materials. Modern techniques such as Just-in-time delivery, and use of information technology such as Project Management Information System (PMIS), are targeted to improve the efficiency of the logistics. Such IT-driven management techniques can be further benefited from state-of-the-art devices such as Radio Frequency Identification (RFID) tags and Ubiquitous Sensor Networks (USN), which has resulted in notable achievements in automated logistics management at the construction sites. Based on those achievements, this research develops USN hardware toolkits for construction lifts, which aims to be automated the vertical material delivery by sensing the material information and routing it automatically to the right place. The gathered information from the sensors can also be used for monitoring the overall status. The developed system will be tested in the actual high-rise construction sites to assess the system's feasibility. The proposed system is being implemented using Zigbee communication modules and RFID sensor networks which will communicate with the intelligent palette system (previously developed by the authors). To support the system, a lift-mountable intelligent toolkit is under development. Its feasibility test will be conducted by applying the implemented system to a test bed and then analyzing efficiency of the system and the toolkit. The collected test data will be provided as a basis of autonomous vertical transport equipment development. From this research, efficient management of the material lift is expected with increased accuracy, as well as better management of overall construction schedule benefited from the system. Further research will be expected to develop a smart construction lift, which will eliminate the need for human supervision, thus enabling a real 'autonomous' operation of the system.

• 한국실내디자인학회논문집
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• 제25호
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• pp.155-161
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• 2000

'Transparency', which has been an important topic of architectural discourse in the recent past, is playing an even greater role in architectural expression nowadays. The purpose of this study is to define the prevailing conceptions about transparency and to discover the various modes of this design effect in architectural space. By using partial or complete of transparency in a structure, designers are able to express themselves more profoundly. The perception between exterior and interior, transformation of day into night and conditions arising from spatial overlapping create an atmosphere which deepens the quickly of architectural design. Transparency can present as void what in reality is solid. Following the period of de-construction, transparency has asserts itself in late part of the century and transparency can be considered synonymous with modernistic and refers to structure that are optically luminant or pleasant in its simplicity. Along with advancement of climate control, construction and design technologies and new material with versatility should combine to even further the diversity of transparency in architectural expression.

• 한국실내디자인학회논문집
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• 제13권5호
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• pp.39-47
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• 2004

In modem days when architectural materials have grave impacts on overall design expression, materials for architecture, especially finishing materials have become the most essential elements for the design expression, as architectural space and form have been. This study closely verifies the concept of tensity analyzed in preceding studies by quantifying it through experimentation and questionnaire, and suggests possible alternatives which verified concept of tensity applies into the architectural design. It was examined how architects consider the finishing materials through a questionnaire. With a questionnaire, the possibility of quantificative analysis for tensity is evaluated by SPSS program. Moreover, a questionnaire about the social image that the architectural finishing materials have was also conducted. This questionnaire results In the actual methods to apply quantificated psychological tensity and social images into the architectural design and recommends better plan to select finishing materials for each spacial function and usage, Due to the great influence of social images in design expression, the application mechanism of the tensity should follow the general and individual principles together. With the tensity figure and application of social images we can find more resonable method for material selection.

• 한국공간구조학회논문집
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• 제16권4호
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• pp.67-73
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• 2016

This paper is a study on Development of polyhedral surfaces Quasicrystal System. Quasicrystal is the quasi-crystalline material, which is the intermediate material of the crystalline material and non-crystalline material. Quasicrystal is a structures that is ordered but not periodic, the basic form is a rhombus. These studies in the field of chemistry will proceed actively studied, in the field of construction a situation that still insufficient research. Therefore, in this paper, we presents the analysis of Quasicrystal system, and the research on the applicability of as dome structures. This paper described some examples of polyhedron form, and method of applying Quasicrystal system.

• Steel and Composite Structures
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• 제27권2호
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• pp.177-184
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• 2018

This study contributes to evaluate multiphase topology optimization design of plate-like structures on elastic foundations by using classic plate theory. Multi-material optimal topology and shape are produced as an alternative to provide reasonable material assignments based on stress distributions. Multi-material topology optimization problem is solved through an alternative active-phase algorithm with Gauss-Seidel version as an optimization model of optimality criteria. Stiffness and adjoint sensitivity formulations linked to thin plate potential strain energy are derived in terms of multiphase design variables and Winkler-Pasternak parameters considering elastic foundation to apply to the current topology optimization. Numerical examples verify efficiency and diversity of the present topology optimization method of elastic thin plates depending on multiple materials and Winkler-Pasternak parameters with the same amount of volume fraction and total structural volume.

• Steel and Composite Structures
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• 제48권5호
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• pp.583-597
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• 2023

This paper introduces a novel approach to multi-material topology optimization (MTO) targeting in-plane bi-directional functionally graded (IBFG) non-uniform thickness Reissner-Mindlin plates, employing an alternative active phase approach. The mathematical formulation integrates a first shear deformation theory (FSDT) to address compliance minimization as the objective function. Through an alternating active-phase algorithm in conjunction with the block Gauss-Seidel method, the study transforms a multi-phase topology optimization challenge with multi-volume fraction constraints into multiple binary phase sub-problems, each with a single volume fraction constraint. The investigation focuses on IBFG materials that incorporate adequate local bulk and shear moduli to enhance the precision of material interactions. Furthermore, the well-established mixed interpolation of tensorial components 4-node elements (MITC4) is harnessed to tackle shear-locking issues inherent in thin plate models. The study meticulously presents detailed mathematical formulations for IBFG plates in the MTO framework, underscored by numerous numerical examples demonstrating the method's efficiency and reliability.

• 대한건축학회논문집:구조계
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• 제35권7호
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• pp.179-186
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• 2019

Air lime is a traditional building material of Korea. It had been used in roofs, walls, floors and masonry joints of traditional buildings until the advent of Portland cement. However, due to its low strength and durability, the lime is currently avoided as a repair or restoration material for the preservation of architectural heritage. Furthermore, due to the current practice of using hydraulic materials such as Portland cement, understanding of the material characteristics of air lime is very poor in practice. In this context, this study intended to improve the mechanical properties of the air lime mortar by reducing water contents, and also the carbonation reaction of the mortar was quantitatively evaluated to clearly understand the characteristics of this material. Accordingly, air lime mortar with a water-to-binder ratio of 0.4 was manufactured using polycarboxylate-type superplasticizer. During the 7 days of sealed curing period, the mortar did not harden at all. In other words, there was no reaction required for hardening since it could not absorb carbon dioxide from the atmosphere. However, once exposed to the air, the compressive strength of the mortar began to rapidly increase due to the carbonation reaction, and the strength increased steadily until the 28th day; after then, the strength development was significantly slowed down. On the 28th day, the mortar exhibit a compressive strength of about 5 MPa, which is equivalent to the European standard regarding strength of hydraulic lime used for preservation of architectural heritage.

• 건축역사연구
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• 제14권4호
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• pp.59-72
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• 2005

Architectural embodiment of a national identity has long been a significant topic in Korean architectural circles. For this reason, it must be helpful to examine the so-called, 'National Romanticism' of Finnish architecture around 1900 in that Finnish architects of the time struggled to embody their national identity through their projects. Considering the historical and linguistic affinities between Finland and Korea, the Finnish architectural situation draws . our additional attention. This paper aims at showing its historical background, the meaning of each type of buildings in the stream, and limitations it implies. The atmosphere of Finnish nationalist movement, which was provoked by [Kalevala] publications (1835; 1845) and shown in Karelianism, was heightened by Tsarist Empire's Russification programme of Finland in the late 19th century Architecture was one of the most important genres expressing her national identity. Finnish national romantic architecture could be divided into three. The first is a log house style for artists' studio house, motivated by the Finnish vernacular farmstead - especially by Karelian farmhouse. This type of building signifies the Finns' will to return to their motherly soil. The second is a stone architecture style for public buildings, inspired by Finnish church or castle of an early medieval time. By using roughly-cut granite as the main exterior material, buildings of this type symbolise the toughness of legendary heroes and Finns' desire for national Independence. The third type of building was based on both of the former or more dependent on architects' Imagination and creativity. However, Finnish national romantic architecture has been criticised by some critics owing to its decorative, eclectic and self-indulgent characteristics. Probably, it was not really national but rather inter-national because of the Influences of English Arts and Crafts Movement, the American Richardsonian architecture and the continental Art Nouveau. And the negative images of 'national' and 'romantic' made some historians coin other terms like 'national realism' or 'material realism'. As another limitation, one raises the low degree of its contribution to the entire architectural history. Despite these criticisms, however, this paper argues that Finnish national romantic architecture is meaningful in itself, particularly because it illustrates vividly Finns' struggle to search for their national identity and, after all, their craving for national independence.

• 한국실내디자인학회논문집
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• 제14권2호
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• pp.55-62
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• 2005

In modern days when architectural materials have grave impacts on overall design expression, materials for architecture, modern architecture into the service facility for business, education, religion, cultural assembly and residence, and evaluates each finishing material mainly used in exterior, lobbies and entrances of the building since the 1970's. When being applied social images into firstly selected materials, the scopes for material selection will be more narrowed down in more practical way. High tensity materials are suitable for public and active space and low tensity are for private and static area. This principle enables us to use architectural materials as one of the important elements which express the whole characteristics of the area.