• Title/Summary/Keyword: Wooden Materials

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MICROMORPHOLOGICAL ASPECTS OF HARDWOODS DETERIORATED IN THE SEA-WATER FROM WRECKED SHIP'S TIMER (수침목재의 재질분석에 관한 연구-미시형태적 변화를 중심으로)

  • KIM, Yoon-Soo;CHOI, Kwang-Nam
    • 보존과학연구
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    • s.7
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    • pp.246-264
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    • 1986
  • Micoromorphological alterations of sea-waterlogged woods by marinemicro-oragnisms were investigated by the light and scanning electron microscopy as a part of serial investigations on the shipwrecked materials which were excavated at the sea shore of Wando-Kun, southern coast of Korea in 1984.Deterioration of sea-waterlogged wood by marine microorganisms were varied with the wood species. The degree of deterioration even in the same wood specieswas different according to the part where it was in mud of sea-water. However, the resistance of Torreya nucifera over the marine organisms was marked. Deterioration in cell wall may be classified into three types; thinning of cell wall, separation of secondary wall from compound middle lamella and tunneling of cell wall. Thinning and separation were frequently observed, while the tunneling was rare. Among the wood cell elements of hardwoods, vessel wall was the least deteriorated. The difference degree of degradation of cell wall constituents and the accumulation of inorganic substances in cell lumen indicate that some factors to be considered for the conservation treatment were discussed. The kinds of marine microorganisms invading and/or inhabiting in wrecked wooden ship were also discussed.

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Application of Incremental Sheet Metal Forming for Automotive Body-In-White Manufacturing (점진적 성형 기술을 이용한 자동차 차체 모형 제품의 제작)

  • Lee, S.U.;Nguyen, D.T.;Kim, N.K.;Yang, S.H.;Kim, Y.S.
    • Transactions of Materials Processing
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    • v.20 no.4
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    • pp.279-283
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    • 2011
  • Recently incremental sheet metal forming (ISF) has used widely in making prototypes and small-volume products in automotive industry etc. We apply the ISF to make a 1/4 sized automobile body-in-white. First, ISF tests for rectangular shaped cup have been performed to clarify the formability denoting the relationship between the component wall angle and maximum cup height of safe forming. Next, a CAD model for the automobile was designed and segmented into several components in order to accommodate the working space of the CNC machine we adopted and the formability of the sheet metal. Then, a CAM software was employed to generate the tool path for manufacturing wooden dies and all the small parts. Finally, the different parts were joined into a single component by laser welding after the ISF process. By using the ISF we successfully produced the 1/4 sized automobile body-in-white.

Stress Distribution near the Joint of Different Materials (서로 다른 재료(材料)의 결합부(結合部)에서의 응력전달(應力傳達))

  • S.J.,Yim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.7 no.1
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    • pp.13-26
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    • 1970
  • An elastic plate bar jointed to a rigid bar is considered. The bar is subjected to uniform axial tension. A theoretical approximate solution is obtained in an infinite hyperbolic series form and some numerical results for various Poisson's ratios are presented. A rubber plate joined to a strong wooden plate has been tested to obtain an experimental data and the results are compared with theoretical ones. Two values for vertical displacements are in good agreement but it is not satisfactory for horizontal displacements. The conclusion arrived at are as follow : The natures of stress distributions and deformed shapes given by above theoretical solution are compatible in mechanical sense. The magnitudes of stress and displacement components would not be reliable for exact works. A sharp shear stress concentrations are detected at the both ends of the joint.

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Repair work of Sasungjeon, one of the main building of Jangansa temple, and an attempt to transform the repair system of historic architecture in 1940s (금강산 장안사 사성전 보존 수리공사와 1940년대 수리체제 전환 시도)

  • Seo, Hyowon
    • Journal of architectural history
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    • v.29 no.4
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    • pp.7-16
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    • 2020
  • The purpose of this study is to reveal the development process of modern repair systems in the Korean peninsula. Sasungjeon, one of the main buildings of Jangansa temple located in Geumgangsan, was repaired from 1941 to 1944. It was the very last restoration work of historic wooden architecture performed during the Japanese colonial era. This work was delayed multiple times because of insufficient materials and human resources. The Bureau of Education(學務局), which was in charge of repair work, understood that the problems of the repair system and suggested reorganizing the system as a solution. This study examined the repair work of Sasungjeon as a background of the bureau's suggestion and considered this suggestion as an attempt to transform the repair system.

Analysis of Suitability of Oriented Strand Board(O.S.B) as a Flooring Board (플로어링보드용으로서 배향성스트랜드보드(O.S.B)의 적합성 분석)

  • Shin, Sang-Ho;Park, Cheul-Woo;Lim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.213-214
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    • 2019
  • Oriented strand board(O.S.B) is used in many areas, such as interior and interior finishes of wooden houses, but no cases and studies have been used as flooring materials for flooring boards. In this study, we will examine the quality and performance of the aromatic strands board, which we believe can be substituted for the plywood, and analyze its suitability as a floorboard.

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Design Optimization of an Impact Limiter Considering Material Uncertainties

  • Lim, Jongmin;Choi, Woo-Seok
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.2
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    • pp.133-149
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    • 2022
  • The design of a wooden impact limiter equipped to a transportation cask for radioactive materials was optimized. According to International Atomic Energy Agency Safety Standards, 9 m drop tests should be performed on the transportation cask to evaluate its structural integrity in a hypothetical accident condition. For impact resistance, the size of the impact limiter should be properly determined for the impact limiter to absorb the impact energy and reduce the impact force. Therefore, the design parameters of the impact limiter were optimized to obtain a feasible optimal design. The design feasibility criteria were investigated, and several objectives were defined to obtain various design solutions. Furthermore, a probabilistic approach was introduced considering the uncertainties included in an engineering system. The uncertainty of material properties was assumed to be a random variable, and the probabilistic feasibility, based on the stochastic approach, was evaluated using reliability. Monte Carlo simulation was used to calculate the reliability to ensure a proper safety margin under the influence of uncertainties. The proposed methodology can provide a useful approach for the preliminary design of the impact limiter prior to the detailed design stage.

Plan Dimension of the Wooden Architecture with a Special Reference of Yingzaofashi(營造法式) of Song Dynasty (송(宋) "영조법식(營造法式)" 을 통해 본 목조건축(木造建築) 평면(平面) 척도구성(尺度構成)의 고찰(考察))

  • Lee, Yong-Jun
    • Journal of architectural history
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    • v.14 no.3 s.43
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    • pp.119-128
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    • 2005
  • In ancient times, architectural design was seen as a critical task in building technologies. Specifically, form, dimension and structural design are of significant. These aspects are associated with each other and to be emerged as a whole. Designing plan dimension was deemed to be the core of design technology due to its close relationship with module system. Thus, its evolution as well as development process typically represents and reflects the spirits and contents of design technologies in ancient China. In China, the materials regarding ancient architectural technology include Yingzaofashi(營造法式) of Song Dynasty and Gongchengzuofazeli(工程做法則例) of Qing Dynasty. They show many aspects concerning materials, structure, scale system and building. In Yingzaofashi, although the length of objects are decided by 'cai(材)' and 'fen(分)', there are no regulations on length, width and height of a building. However, in the construction of ancient buildings, the above mentioned basic scales are very important in both design and construction. The present paper attempts to discuss the significance, namely, the design principles of length, with and height of ancient chinese architecture.

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Development of Satisfaction Models for Passenger Car Interior Materials Considering Statistical, Technical, and Practical Aspects of Design Variables (설계변수의 통계적.기술적.실질적 측면을 고려한 자동차 내장재질의 만족도 모형 개발)

  • You, Hee-Cheon;Ryu, Tae-Beum;Oh, Kyung-Hee;Yun, Myung-Hwan;Kim, Kwang-Jae
    • IE interfaces
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    • v.17 no.4
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    • pp.482-489
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    • 2004
  • As the functional characteristics of passenger cars have reached to a satisfactory level, customers place more concerns with the aesthetic aspects of interior designs. The present study developed satisfaction models of passenger car interior materials for six parts including crash pad, steering wheel, transmission gearshift knob, audio panel, metal grain, and wooden grain. Eight to fifteen material design variables such as color, embossing, and smoothness were defined for the six interior parts based on literature survey, customer reviews, and expert opinions. A satisfaction survey was conducted for 30 vehicles with 30 participants ($mean{\pm}SD$ of age = $28.7{\pm}6.6$) by using a modified magnitude estimation scale. Based on the survey results, the material design variables were screened from statistical, technical, and practical aspects. With the screened variables, satisfaction models were developed by using the quantification I method for the six interior parts, indicating the importance of material design variables and preferred material properties.

Leachability of Zinc Borate-Modified Oriented Strandboard (OSB)

  • Lee, Sun-Young;Wu, Qinglin
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.46-57
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    • 2007
  • The leachability of boron in zinc borate (ZB)-modified oriented strandboard (OSB) from southern wood species was investigated in this study. The leaching experiments were conducted by exposing edge-sealed OSB samples under running water at $31^{\circ}C$ for 8, 24, 72, and 216 h. The results from leached samples were compared with those from the unleached controls. Boron leaching of the modified OSB occurred upon the initial water exposure, and the leaching rate decreased as the leaching time increased. Initial boric acid equivalent (BAE) level, wood species, and sample thickness swelling significantly influenced the leachability. There was no consistent effect of polyethylene glycol (PEG) on zinc borate leaching. The glue-line washing within OSB due to thickness swelling of the test samples under water and decomposition of the borate to form water-soluble boric acid were thought to be two possible causes for the observed leaching. The relationship between assayed BAE and leaching time followed a decaying exponential function for zinc borate treated OSB. From the boron/zinc ratio after each leaching period, boron element in ZB was more or less leachable. The material constant of the regression models allowed comparing the leachability of the modified OSB for various wood species. An unified leaching method for treated wood composite materials is needed.

Evaluation of Indoor Thermal Environment according to Type and Color of Blinds Installed in the Classroom (교실에 설치된 블라인드의 유형과 색상에 따른 실내 온열환경 평가)

  • Kwon, Daehyeok;Lee, Jae-Ro;Oh, Juseok;Wi, Seunghwan;Kim, Sumin
    • Journal of the Korea Furniture Society
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    • v.28 no.3
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    • pp.224-232
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    • 2017
  • Building energy saving have been put effort in a long time since buildings consume about 40.6% of total energy use, where heating, cooling and electrical lighting requirement results in energy consumption of building significantly. The window is an important part of building envelope, it usually brings a certain heat load from solar radiation while it allows light passing through, and properly leads to overheating in summer, hence the cooling load increase sand cause of thermal uncomfortable factor. The purpose of this study was to evaluate internal shade performance according to color and materials. There is growing interest in improving the sense of comfort among students who spend most of their time in the classroom. The study examined thermal environment and light environmental performance according to the color and materials of internal blinds to the school classroom. The results of this study were as follows; Among wooden blinds, aluminium blinds, and polyester blinds, the aluminium blinds were most excellent. In addition, among white blinds, light brown blinds, dark brown blinds, the light brown were most excellent.