• Title/Summary/Keyword: Skin elements

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Numerical investigation on the response of circular double-skin concrete-filled steel tubular slender columns subjected to biaxial bending

  • Abu-Shamah, Awni;Allouzi, Rabab
    • Steel and Composite Structures
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    • v.37 no.5
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    • pp.533-549
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    • 2020
  • Recently, Concrete-filled double skin steel tubular (CFDST) columns have proven an exceptional structural resistance in terms of strength, stiffness, and ductility. However, the resistance of these column members can be severely affected by the type of loading in which bending stresses increase in direct proportion with axial load and eccentricity value. This paper presents a non-linear finite element based modeling approach that studies the behavior of slender CFDST columns under biaxial loading. Finite element models were calibrated based on the outcomes of experimental work done by other researchers. Results from simulations of slender CFDST columns under axial loading eccentric in one direction showed good agreement with the experimental response. The calibrated models are expanded to a total of thirty models that studies the behavior of slender CFDST columns under combined compression and biaxial bending. The influences of parameters that are usually found in practice are taken into consideration in this paper, namely, eccentricity-to-diameter (e/D) ratios, slenderness ratios, diameter-to-thickness (D/t) ratios, and steel contribution ratios. Finally, an analytical study based on current code provisions is conducted. It is concluded that South African national standards (2011) provided the most accurate results contrasted with the Eurocode 4 (2004) and American Institute of Steel Construction (2016) that are found to be conservative. Accordingly, correction factors are proposed to the current design guidelines to provide more satisfactory results.

A new design chart for estimating friction angle between soil and pile materials

  • Aksoy, Huseyin Suha;Gor, Mesut;Inal, Esen
    • Geomechanics and Engineering
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    • v.10 no.3
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    • pp.315-324
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    • 2016
  • Frictional forces between soil and structural elements are of vital importance for the foundation engineering. Although numerous studies were performed about the soil-structure interaction in recent years, the approximate relations proposed in the first half of the 20th century are still used to determine the frictional forces. Throughout history, wood was often used as friction piles. Steel has started to be used in the last century. Today, alternatively these materials, FRP (fiber-reinforced polymer) piles are used extensively due to they can serve for long years under harsh environmental conditions. In this study, various ratios of low plasticity clays (CL) were added to the sand soil and compacted to standard Proctor density. Thus, soils with various internal friction angles (${\phi}$) were obtained. The skin friction angles (${\delta}$) of these soils with FRP, which is a composite material, steel (st37) and wood (pine) were determined by performing interface shear tests (IST). Based on the data obtained from the test results, a chart was proposed, which engineers can use in pile design. By means of this chart, the skin friction angles of the soils, of which only the internal friction angles are known, with FRP, steel and wood materials can be determined easily.

Planning of the Blind Position Considering Thermal Performance in the Intermediate Space of Double-Skin Facade

  • Choi Dong-Hee;Jo Jae-Hun;Seok Ho-Tae;Yeo Myoung-Souk;Kim Kwang-Woo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.14 no.2
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    • pp.57-65
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    • 2006
  • The blinds in the intermediate space are installed to block the direct solar radiation. As the blind divides the airflow of intermediate space into two parts, thermal performance of Double-Skin Facade(DSF) is affected by the blind position. Therefore the blind position should be planned with careful consideration in order to maximize the thermal performance of DSF. In this study, CFD was performed to analyze the effect of blind position in multistory-type DSF in variation of other DSF elements. The simulation results showed that the case with narrow depth of intermediate space and outlet on upper side of outer-facade, it is profitable to place blind as close as possible to the outer facade. In the other cases, the blind should maintain 0.15m distance from outer facade.

A Simple Model Parameter Extraction Methodology for an On-Chip Spiral Inductor

  • Oh, Nam-Jin;Lee, Sang-Gug
    • ETRI Journal
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    • v.28 no.1
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    • pp.115-118
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    • 2006
  • In this letter, a simple model parameter extraction methodology for an on-chip spiral inductor is proposed based on a wide-band inductor model that incorporates parallel inductance and resistance to model skin and proximity effects, and capacitance to model the decrease in series resistance above the frequency near the peak quality factor. The wide-band inductor model does not require any frequency dependent elements, and model parameters can be extracted directly from the measured data with some curve fitting. The validity of the proposed model and parameter extraction methodology are verified with various size inductors fabricated using $0.18\;{\mu}m$ CMOS technology.

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A study of Beauty Make-up Using Computer Graphics (뷰티 메이크업을 위한 컴퓨터 그래픽스 활용에 관한 연구)

  • Kwon, Hyun-Ah
    • Fashion & Textile Research Journal
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    • v.8 no.2
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    • pp.214-224
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    • 2006
  • Computer graphics mean a reproduction of various information through image processing or the technology that is widely thought in makeup areas also, recently. Especially, Adobe Illustrator, unlike Adobe Photoshop used in image editing and correction, is software suitable for image drawing and reproducing beauty makeup. Beauty makeup is a work adorning human body to fit to the aesthetic standard in that period, and is a plastic art expressing shapes, colors and textures using design elements. Adobe Illustrator is a 2D graphics designing images using shapes having plane colors. In this study I studied techniques reproducing each element of contours and colors of beauty makeup through Adobe Illustrator CS. In other words, I have prepared a reference data by studying techniques reproducing beauty makeup using Adobe Illustrator CS. In this study, though, I couldn't try various things, because I limited facial contour and skin color to only one kind. Therefore, I hope, in the future, others can expand the ethnics of using Adobe Illustrator in more enriched ways by working on various facial contours and skin colors.

European Elements Appeared in Costume Materials of the North American Indian (북아메리칸 인디언의 복식재료에 나타난 유럽적 요소)

  • 이민경;한명숙
    • The Research Journal of the Costume Culture
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    • v.6 no.4
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    • pp.39-49
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    • 1998
  • When considering clothing of the North American Indians, it is important to understand historical background of the North American Indians. With the coming of he Europeans, the North American Indians adopted new materials of clothing and ornamentation and added European elements to their own dresses. New materials appeared in textiles, beadswork, and metalwork. The introduction of the "true" loom and steel needle by the Spanish led in the New World to the development of a weaving culture. Cotton cloth, in calico prints, gingham, or plain were made into dresses, and colorful applique, patchwork designs adapted from the white women. Cloth made an immediate impact, replacing skin that is so time-consuming in preparation. Glass beads, pony beads, seed beads and ribbons were used to create adornment Indian clothing. Brass, tin and silver were used among Indian metalworkers to make some ring, necklace, bracelet, etc.

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SPICE models of PCB traces in high-speed systems (고속 시스템에서의 PCB 선로의 SPICE 모델)

  • 남상식;손진우;강석열;김석윤
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.1
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    • pp.12-20
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    • 1997
  • Physical interconnect such as Printed Circuit Board(PCB) traces introduces new challenges for parameter extraction and delay calculation for high-speed system design. PCB traces are dominated by frequency dependent LC propagation which makes precharacterization difficult for all possible configurations. Moreover, simulating the transient behavior of the trace for noise and delay analysis requries the combined used of a variety of models and techniques for efficiently handling lossy, low-loss, frequency dependent, and coupled transmission lines together with lumped elements. In this paper we explain how the frequency dependence caused by ground plane proximity and skin effects can be modeled using the adstracted models. These abstracted (lumped) models are SPICE-compatible and can be simulated in time-domain, along with precharacterized lumped parasitic elements and nonlinear driver and load models.

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A Study on the Negative Skin Friction based on Measurements from Existing Works Analysed by 3D Finite Element Analyses (기발표 실측치 분석을 기반으로 한 3차원 유한요소해석 수행을 통한 부마찰에 관한 연구)

  • Jeon, Sang Joon;Jeon, Young Jin;Jeon, Seung Chan;Lee, Cheol Ju
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.8
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    • pp.15-27
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    • 2020
  • In the current paper, a series of advanced 3D finite element analyses have been performed on existing pieces of work of negative skin friction from a geotechnical centrifuge test and full-scale field measurements. From these analyses, key features of pile behaviour under the influence of negative skin friction which, previously, were not fully understood in existing studies, have been meticulously discussed. As such, it has been possible to successfully address several numerical modelling issues such as negative skin friction induced pile settlements and group effects (the shielding effect), the effect of sacrificial piles in groups and the interaction between the pile head and the cap, the effect of interface elements at the pile-soil interface and the time-dependent pile behaviour. During a geotechnical centrifuge test, substantial amounts of negative skin frictions were mobilised when centrifugal acceleration increased from 1g to a certain g-level due to an increase in the self-weight of soil. The behaviour of piles inside a group were heavily affected by the sacrificial piles and the connectivity between the pile head and the pile cap. In particular, as negative skin friction has time dependent qualities associated with consolidation, it was logical to perform coupled analyses when analysing piles in consolidating grounds. From the current work, several insufficiencies of previous researches have been addressed, and the engineering pile behaviour subjected to negative skin friction has been clarified.

A mono-material tactile sensor with multi-sensing properties

  • Shida, Katsunori;Yuji, Junnichiro
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.587-592
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    • 1994
  • To realize artificial device with sensing ability of the human skin, a mono-material tactile sensor with three sensing functions made of some elastic thin electro-conductive rubber sheet with eight latticed patch elements is proposed. This trial sensor provides the information of three kinds of model material characteristics such as thermal property, hardness property and the surface situation of materials by setting up three kinds of surface models as test materials. It can be finally expected to estimate unknown model materials by analyzing the data of the sensor.

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A Study on Perceptions of Virtual Influencers through YouTube Comments -Focusing on Positive and Negative Emotional Responses Toward Character Design- (유튜브 댓글을 통해 살펴본 버추얼 인플루언서에 대한 인식 연구 -캐릭터 디자인에 대한 긍부정 감성 반응을 중심으로-)

  • Hyosun An;Jiyoung Kim
    • Journal of the Korean Society of Clothing and Textiles
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    • v.47 no.5
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    • pp.873-890
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    • 2023
  • This study analyzed users' emotional responses to VI character design through YouTube comments. The researchers applied text-mining to analyze 116,375 comments, focusing on terms related to character design and characteristics of VI. Using the BERT model in sentiment analysis, we classified comments into extremely negative, negative, neutral, positive, or extremely positive sentiments. Next, we conducted a co-occurrence frequency analysis on comments with extremely negative and extremely positive responses to examine the semantic relationships between character design and emotional characteristic terms. We also performed a content analysis of comments about Miquela and Shudu to analyze the perception differences regarding the two character designs. The results indicate that form elements (e.g., voice, face, and skin) and behavioral elements (e.g., speaking, interviewing, and reacting) are vital in eliciting users' emotional responses. Notably, in the negative responses, users focused on the humanization aspect of voice and the authenticity aspect of behavior in speaking, interviewing, and reacting. Furthermore, we found differences in the character design elements and characteristics that users expect based on the VI's field of activity. As a result, this study suggests applications to character design to accommodate these variations.