• Wind and Structures
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• 제37권2호
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• pp.133-151
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• 2023

This paper first provides a wide overview about the design codes and standards covering the use of Computational Wind Engineering / Computational Fluid Dynamics (CWE/CFD) for wind-sensitive structures and built environment. Second, the paper sets out the basic assumptions and underlying concepts of the new Annex T "Simulations by Computational Fluid Dynamics (CFD/CWE)" of the revised version "Guide for the assessment of wind actions and effects on structures" issued by the Advisory Committee on Technical Recommendations for Constructions of the Italian National Research Council in February 2019 and drafted by the members of the Special Interest Group on Computational Wind Engineering of the Italian Association for Wind Engineering (ANIV-CWE). The same group is currently advising UNI CT021/SC1 in supporting the drafting of the new Annex K - "Derivation of design parameters from wind tunnel tests and numerical simulations" of the revised Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions. Finally, the paper outlines the subjects most open to development at the technical and applicative level.

• Journal of the Korean Wood Science and Technology
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• 제52권4호
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• pp.301-318
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• 2024

Contrary to other materials like metals, glass, etc., wood continuously interacts with the environment, increasing and decreasing its moisture content according to the humidity of the air and changing its dimensions by swelling or shrinking. Water diffusion through laminated solid wood is crucial in wood bonding processes. The adhesive layer might block the diffusion if the water vapor diffusion is perpendicular to the bond line. As a result of this blockage, different proportions of deformation appear on the two sides of the bond line, which causes stresses in the bonded assembly. The question arises of how long the bonded structure will keep its integrity due to moisture diffusion blockage, inevitable tensions appearing in the glue line, and how these stresses could be avoided. With cross laminated timber (CLT) solid wood panel production, this question gains new importance. Despite the relevance, only a limited number of publications are available. Comprehensive research would also be necessary considering both the molecular structure and diffusion properties of the adhesive adjusted to the wood species (covering possible substituting wood species, too). Overall, this review serves as a resource for enhancing our understanding of water vapor diffusion through wood adhesive layers and provides insights that have implications for reducing stresses in bonded wood assemblies and the performance of the bonded group over time. Furthermore, identifying knowledge gaps is necessary to establish the basis for investigating the diffusion property of CLT panels.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.142.2-142.2
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• 2015

Plasma etch endpoint detection (EPD) of SiO2 and PR layer is demonstrated by plasma impedance monitoring in this work. Plasma etching process is the core process for making fine pattern devices in semiconductor fabrication, and the etching endpoint detection is one of the essential FDC (Fault Detection and Classification) for yield management and mass production. In general, Optical emission spectrocopy (OES) has been used to detect endpoint because OES can be a simple, non-invasive and real-time plasma monitoring tool. In OES, the trend of a few sensitive wavelengths is traced. However, in case of small-open area etch endpoint detection (ex. contact etch), it is at the boundary of the detection limit because of weak signal intensities of reaction reactants and products. Furthemore, the various materials covering the wafer such as photoresist (PR), dielectric materials, and metals make the analysis of OES signals complicated. In this study, full spectra of optical emission signals were collected and the data were analyzed by a data-mining approach, modified K-means cluster analysis. The K-means cluster analysis is modified suitably to analyze a thousand of wavelength variables from OES. This technique can improve the sensitivity of EPD for small area oxide layer etching processes: about 1.0 % oxide area. This technique is expected to be applied to various plasma monitoring applications including fault detections as well as EPD.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.60-60
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• 2015

Nanosheets of graphene and related 2D materials have attracted much attention due to excellent physical, chemical and mechanical properties. Single-layer graphene (SLG) was first synthesized by Blakely et al in 1974 [1]. Following his achievements, we initiated the growth and characterization of graphene and h-BN on metal substrates using surface segregation and precipitation in 1980s [2,3]. There are three important steps for nanosheet growth; surface segregation of dopants, surface reaction for monolayer phase, and subsequent 3-D growth (surface precipitation). Surface phase transition was clearly demonstrated on C-doped Ni(111) by in situ XPS at elevated temperatures [4]. The growth mode was clarified by inelastic background analysis [5]. The surface segregation approach has been applied to C-doped Pt(111) and Pd(111), and controllable growth of SLG has been demonstrated successfully [6]. Recently we proposed a promising method for producing SLG fully covering an entire substrate using Ni films deposited on graphite substrates [7]. A universal method for layer counting has been proposed [8]. In this paper, we will focus on the effect of competitive surface-site occupation between carbon and other surface-active impurities on the graphene growth. It is known that S is a typical impurity of metals and the most surface-active element. The surface sites shall be occupied by S through surface segregation. In the case of Ni(110), it is confirmed by AES and STM that the available surface sites is nearly occupied by S with a centered $2{\times}2$ arrangement. When Ni(110) is doped with C, surface segregation of C may be interfered by surface active elements like S. In this case, nanoscopic characterization has discovered a preferred directional growth of SLG, exhibiting a square-like shape (Fig. 1). Also the detailed characterization methodologies for graphene and h-BN nanosheets, including AFM, STM, KPFM, AES, HIM and XPS shall be discussed.

• 한국지반환경공학회 논문집
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• 제17권11호
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• pp.23-33
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• 2016

본 연구에서는 해저에 퇴적된 오염 침전물질을 제올라이트와 모래로 피복하여 중금속 및 오염물질을 격리하는 피복 공법을 적용한 지역의 해저지반의 역학적 안정성 및 변형 예측을 하였다. 문헌조사와 현장조사를 바탕으로 분석해 본 결과, 이 현장에 맞는 피복재는 중금속 흡착효과가 뛰어난 제올라이트가 적합한 것으로 결정되었다. 정밀지반조사 결과를 바탕으로 오염 침전물질을 제올라이트와 모래로 피복한 후 주변 지반에 대한 안정성 평가와 압밀로 인한 장기지반거동을 예측하였다. 역학적 안정해석 결과, 지면이 해수에 포화되는지 여부에 따라 최저 안전율은 약 11.2와 30.1로 계산되어 충분히 안전한 것으로 판단되었다. 압밀량 해석을 진행한 결과 상단면 기준으로 1차 최대압밀량이 209.2mm 정도 발생하고 2차 압밀량은 1.2mm로 아주 적게 예측되었다. 시간에 따른 압밀도를 계산하여 시간에 따른 1차압밀량도 예측하였다.

• 한국안전학회지
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• 제33권3호
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• pp.15-20
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• 2018

There have been a number of major fatal fire accidents in Korea recently. The number of fires in 2017 were 44,178, which is not only increasing number of fires but also increasing in casualties. Particularly, the fire at Jecheon Sports Center, which suffered many casualties, is expected to have a huge impact. The cause of the fire has not been determined yet, but heat waves on the ceiling have also been pointed out. As such, the copper heating waves, which are used as a preventive measure against damage of pipes due to freezing of pipes, etc., always have a fire hazard. To determine the possibility of a flame-resistant heated fire, a positive electric cable product was used to artificially ignite and analyze the results. In case of a short circuit, the external covering of the positive electric cable is damaged, but not short circuit unless the heating material surrounding the wire is damaged. Due to the characteristics of heating cable for preventing copper waves, the chances of insulation becoming more severe due to moisture and temperature changes are higher than normal wires. If the internal heating system is carbonized by insulating deterioration without damage to the outer coating, it is likely to cause trekking, to form a winding loop in the heating materials, and to cause short circuit in the heated materials. For the positive temperature line, if the middle is shorted, the current continues to flow to the short circuit unless the breaker disconnects. Consequently, a heated fire that does not cut off the power immediately may leave multiple marks or cuts.

• 한국가정과교육학회지
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• 제14권1호
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• pp.39-54
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• 2002

This study was done to identify contents of clothing and textile education and to systemize its curriculum from elementary school to high school Every time the official curriculum is updated. the suggestion that the contents of Home Economics Education should be systematized never fails to come forth. Unfortunately. it's a fact that there are still insufficient grounds to base this opinion on. and that adequate research has not yet been done in this particular field. Therefore. basic research must be performed in order to systematize the substance of clothing and textile education. Keeping this in mind. the following study strives to find appropriate methods of conducting clothing and textile education, while attempting to provide basic materials for future organization and selection of contents. In order to achieve these goals. the materials have been sorted into three categories : First of all. what sort of concepts is being taught in the subject of clothing and textile. and are the chapters constructed so that different schools can maintain consistency among them\ulcorner Second, how has clothing and textile education been done so far and is the contents correctly synchronized with the students'development\ulcorner Third. haw is clothing and textile education utilized in real life. and has it actually been systematized in a way that encourages practical utilization\ulcorner This study has mostly been done through the research of various documental resources. Also. the analysis has been performed using the systematic contents analysis method. The main results of obtained this study are as follows : As the concepts of clothing and textile education. which are different from each school, has not completely been systematizied. Also. as the contents of clothing and textile education has not correctly synchronized with the students'development. am it has not actually been systematized in a way that encourages practical utilization. Since this study has touched only limited research on the topic of clothing and textile education. it is essential that further research covering a wider array of themes be done in the future.

• 한국의상디자인학회지
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• 제12권4호
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• pp.61-73
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• 2010

The purpose of this study is to create unique formative beauty with free expressive method and to suggest accessory design with individuality through this, by using hand-knitting technique in design of necklace and bangle, which belong to personal ornament among fashion accessories. It analyzed on theoretical background of knit technique and accessory through documentary research, examined the accessory design tendency and the research tendency through collection materials, and then suggested 9 works in accessory ornament design of using hand-knitting technique, based on this. The results are as follows. First, even in overseas collection, accessories in diverse materials and shapes were being show cased. Volume in necklace or bangle was indicated to be big. There were many cases of covering several items together. Second, the hand-knitting technique in originative accessory design could be confirmed to be possibly used broadly in the range of pattern and shape available for making by using yarn in diverse thicknesses with proper technique, and by transforming basic tissue according to knitting technique. Third, through the results of making ornaments in 7 necklaces and 2 bangles, the hand-knitting technique was confirmed to possibly expanding the application range of knitting technique in the accessory field, and has significance in having suggested individual accessory.

• 한국재료학회지
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• 제1권4호
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• pp.177-183
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• 1991

$SiH_4$환원에 의한 선택성 CVD-W 공정에서 증착시간과 증착압력에 따른 W막 특성의 변화를 조사하였다. $300^{\circ}C$, 100mtorr이하에서 W막이 Si기판 전면에 증착되는 데에 약 30초의 시간이 걸렸고, 증착시간에 따라 막 두께는 초기에는 직선적으로, 나중에는 포물선적으로 증가하였으며, 면저항은 초기에는 급히, 나중에는 서서히 감소하는 경향을 나타내었다. 50-300mtorr의 압력범위에서 압력의 증가에 따라 결정립도(grain size)는 별로 변하지 않았으나 결정립계(grain boundary)의 윤곽이 불확실해지는 경향을 나타내었다. 또한 이 압력범위에서는 ${\alpha}-W$만 나타날 뿐 ${\beta}-W$의존재는 발견되지 않았다. 증차압력의 증가에 따라 W막의 증착속도가 증가하고, 비저항도 증가하는 경향을 보였다. AES 분석결과에 의하면, 증착압력온 Si/W의 조성비나 W/Si계면에서의 실리사이드화에는 큰 영향을 미치지 않는 것으로 나타났다.

• 한국컴퓨터정보학회논문지
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• 제25권8호
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• pp.89-98
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• 2020

본 연구에서는 Q방법론을 적용하여 65세 이상 노년 여성을 대상으로 노년 여성의 의복 선호도에 대한 주관적 평가와 인식에 따른 유형별 특성을 알아보고자 하였다. 제1유형의 경우 부드러운 니트 소재와 천연소재, 파스텔 색상, 스커트 착용을 선호하였다. 제2유형의 경우 체형을 커버해주고 젊어 보이는 바지를 선호하였다. 제3유형은 착용감이 편안한 의복을 선호하는 유형이다. 제4유형은 단순한 스타일과 착용감이 편안한 옷을 선호하는 유형이다. 제5유형은 디자인이나 색상이 중요하고 젊어 보이는 스타일을 선호하는 유형이다. 노년 여성의 ZIGTECHnology의복 개발을 위해서는 등의 굽음, 허리의 굽음 등의 체형을 커버하면서 아름답게 보일 수 있는 디자인 개발이 필요하고, 움직임에 장애가 없는 동작 기능성을 고려한 의복 개발이 필요할 것으로 생각된다.