• 한국분말재료학회지
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• 제26권6호
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• pp.528-538
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• 2019

The transition from "More-of-Less" markets (economies of scale) to "Less-of-More" markets (economies of scope) is supported by advances of disruptive manufacturing and reconfigurable-supply-chain management technologies. With the prevalence of cyber-physical manufacturing systems, additive manufacturing technology is of great impact on industry, the economy, and society. Traditionally, backbone structures are built via bottom-up manufacturing with either pre-fabricated building blocks such as bricks or with layer-by-layer concrete casting such as climbing form-work casting. In both cases, the design selection is limited by form-work design and cost. Accordingly, the tool-less building of architecture with high design freedom is attractive. In the present study, we review the technological trends of additive manufacturing for construction-scale additive manufacturing in particular. The rapid tooling of patterns or molds and rapid manufacturing of construction parts or whole structures is extensively explored through uncertainties from technology. The future regulation still has drawbacks in the adoption of additive manufacturing in construction industries.

• Journal of Construction Engineering and Project Management
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• 제7권1호
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• pp.37-49
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• 2017

The Jinshanling section of the Great Wall of China is a series of fortifications in northern China that was constructed for strategic military defenses. This section was first built in the beginning of the Ming Dynasty in AD 1368 and then underwent major construction, reconstruction and renovation during the late Ming Dynasty, approximately in AD 1569. The Jinshanling section is 10.5 km long, a very short section compared with the entire 21,200 km wall. The wall section is located in Luanping County, Hebei province, China. This research paper focuses on the construction methods and materials of the wall and the towers in the area. The research methodology includes site visits, knowledge acquisition of experts and 3D graphic modeling. This study reveals that the materials selected for the structure include rubbles and rammed earth, bricks, stones, timber, and mortar. The erection sequence of the wall and the towers was a bottom-up fashion using various ancient construction techniques, such as the fire-setting rock blasting techniques and the surveying techniques from the Sea Island Mathematical Manual.

• 컴퓨터교육학회논문지
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• 제18권1호
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• pp.35-43
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• 2015

텐지블 프로그래밍 도구는 그래픽 인터페이스 기반의 프로그래밍 방식과는 달리 컴퓨터를 사용하지 않고 손으로 조작하여 프로그래밍 할 수 있는 도구이다. 어린학생을 대상으로 알고리즘을 설계하고 시뮬레이션 하는 경험을 제공하여 논리적 사고 능력을 향상시킬 수 있다. 본 연구에서는 기존에 개발된 텐지블 프로그래밍 도구를 분석하여 도출된 문제점을 수정 보완하기 위해 다수의 명령어를 하나의 블록에 맵핑, 즉시적인 결과 확인, 다양한 수준의 알고리즘 표현이 가능하도록 설계 후 B-Bricks를 개발하였다. 개발한 B-Bricks를 초등학교 4-6학년 29명을 대상으로 적용한 결과, 문항의 난이도가 상승할수록 정답률이 감소하고 문제풀이시간이 증가하는 것으로 분석되었다.

• 건설안전기술
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• 통권55호
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• pp.37-51
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• 2012

There is a shround of mystery surronnding Gaudi. In all probability, the first mist preventing us from gaining acess to his work is the intrinstic mysteriousness of all genius and, at the end of the day, of all human spirit. The situation is complicated by the well-known fact that Gaudi wished to creat an aura of silence around his persona, while, at the same time as maintaining this secretiveneness - in other words, the annihiliation of his fundamental values-gave expression and symbolisation to his moods and incerdible mental power. On a piece of land on the Muntanya Pelada, in the Barcelona district of La Salut, Eusebi G$\ddot{u}$ell Wanted to build an urbanisation inspired by the concepe of the garden city. in this he sought to return to nature, health and an escape from the insalubrous industrial city. Gaudi worked on the construction of this park between 1900 and 1914, and even moved his home there in 1906. An outstanding feature of park G$\ddot{u}$ell is the integration of architecture with nature. In other to save the natural slopes, Gaudi built viaducts from brick pillars, which he covered with stone obtained from the excavation.

• 아동학회지
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• 제35권5호
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• pp.63-82
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• 2014

The purpose of this study is to elucidate how two young children understand force in rough-and-tumble play. For this purpose, a form of microanalysis(Forman, 2006) was used. They regarded black as the strongest color due to their daily experiences. They assumed that a structure made of black Lego-color-bricks would be strongest and made an experiment of beating it against blocks of other colors. Such repetitive behavior ultimately led them to realize that color had no correlation with strength. They also understood mechanical energy by which a boy's pushing power moves against an object. They tried to strike a bigger or protruding structure and understood that parts might be broken more easily by striking. This experience enabled the boys to realize the principle of resistance. That is to say, in the process of rough-and-tumble play, their misconceptions were gradually removed and they obtained scientific knowledge, including understanding of mechanical energy and the principle of resistance. This study found that two young children constructed knowledge together through the process of tool making and in contending for victory in rough-and-tumble play.

• 대한기계학회논문집B
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• 제24권12호
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• pp.1596-1607
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• 2000

The optimal design of auto-catalyst needs a good compromise between the pressure drop and flow uniformity in the substrate. One of the effective methods to achieve this goal is to use the concept of radially variable cell density. But this method has not been examined its usefulness in terms of chemical behavior and conversion performance. In this work, two-dimensional performance prediction of catalyst coupled with turbulent reacting flow simulation has been used to evaluated the benefits of this method n the flow uniformity and conversion efficiency. The results showed that two cell combination of 93cpsc and 62 cpsc was the most effective for improved pressure drop and conversion efficiency due to balanced space velocity and efficient usage of geometric surface area of channels. It was also found that large temperature difference between the bricks in case that the edge of the frontal face of brick has too much lower cell density(less than 67% of cell density of the center of the brick). This study has also demonstrated that the present computational results show the better prediction accuracy in terms of CO, HC and NO conversion efficiencies compared to those of conventional 1-D adiabatic model by comparison with experimental results.

• 한국분말재료학회지
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• 제13권2호
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• pp.102-107
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• 2006

Recycling industrial wastes such as fly ash from a coal burning heat power plant and shell from an oyster farming were investigated to prevent environment contamination as well as to enhance the value of recycling materials. In this study, the lightweight aggregates and the red bricks were fabricated from fly ashes with other inorganic materials and wastes. The starting materials of the lightweight aggregate were fly ash powder and water glass, and the compacts of these materials were heat treated at $1100^{\circ}C$. The fabricated lightweight aggregates had low bulk density, $0.9-1.2\;g/cm^3$, hence floated on the water and had the strength of 7.0-11.0 MPa and the modulus of 2900-3300 MPa which indicates it has enough strength as the aggregate. Another type of the light weight aggregate was prepared from fly ashes, shell powders and clays. The bulk density, porosity, and compressive strength of these aggregates were $1.19-1.34\;g/cm^3,\;18.3{\sim}56.1%$ and 5-12 MPa, respectively. The addition of a small amount of fly ash powder prevented hydration of the light weight aggregates. The red brick was also fabricated from the fly ash containing materials. It is suitable for the brick facing of a building as it has moderate strength and low water absorption rate.

• 분석과학
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• 제26권5호
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• pp.340-351
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• 2013

The chemical element and structural characterization of different types of cements and its brick stones are been investigated under forensic aspects using X-ray florescence (XRF) and X-ray diffraction (XRD) spectrometer. The XRF provides rapid compositional data for controlling almost all stages of raw materials, clinker and cement. The decisive advantage of XRD methods is based on the unique character of the diffraction patterns of crystalline substances, the ability to distinguish between elements and their oxides, and the possibility to identify chemical compounds, polymeric forms, and mixed crystals by non-destructive examination. Therefore, combination of these examinations is useful and able to apply for the forensic analysis in comparison of cements and brick stones. There are more study remained to determine the viability of method for forensic analysis of brick stones and the limits of the discrimination that can be achieved.

• Structural Engineering and Mechanics
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• 제59권3호
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• pp.539-558
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• 2016

Minarets are almost the inevitable part of Mosques in Islam and according to some, from a philosophical point of view, today they symbolize the spiritual elevation of man towards God. Due to slenderness, minarets are susceptible to earthquakes and wind loads. They are mostly built in a masonry style by using cut limestone blocks or occasionally by using bricks. In this study, one minaret (M1 Minaret) of one of the charmest mosques of Turkey, Sultan Ahmed Mosque, popularly known as Blue Mosque, built between 1609 and 1616 on the order of Sultan Ahmed by the architect Mehmet Agha is investigated under some registered earthquake loads. According to historical records, a great earthquake hit Istanbul and/or its close proximity approximately every 250 years. Ottomans tackled with the problem of building earthquake resistant, slender minarets by starting to use forged iron connectors with lead as a filler to fix them to the upper and lower and to adjacent stones instead of using traditional mortar only. Thus, the discrete stones are able to transfer tensile forces in some sense. This study investigates the contribution of lead to the energy absorption capacity of the minaret under extensive earthquakes occurred in the region. By using the software ANSYS/LS-DYNA in modelling and investigating the minaret nonlinearly, it is found out that under very big recorded earthquakes, the connectors of vertical cast iron-lead mechanism play very important role and help to keep the structure safe.

• 한국세라믹학회지
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• 제51권2호
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• pp.103-106
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• 2014

Nacre is an organic-inorganic composite material; it is composed of $CaCO_3$ platelet and protein. The microstructure of nacre is a matrix that is similar to bricks and mortar. Technology inspired by nature is called biomimetic technology. In this study, to make high thermal conducting ceramic composite materials using biomimetic technology, a porous green body was prepared with BN platelets. PMMA was infiltrated into the porous green body to make a composite. The microstructure of the composite was observed with FESEM, and the thermal properties were measured. The thermal conductivity of the prepared organic-inorganic composite was 4.19 $W/m{\cdot}K$.