• 제목/요약/키워드: functional property

검색결과 789건 처리시간 0.032초

Fundamental Investigation of Functional Property of Concrete Mixed with Functional Materials

  • Lee, Jong-Chan;Lee, Moon-Hwan;Lee, Sae-Hyun;Park, Young-Sin;Park, Jae-Myung
    • International Journal of Concrete Structures and Materials
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    • 제18권3E호
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    • pp.165-171
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    • 2006
  • Environment-friendly materials are increasingly used as building construction materials nowadays, and the market share of those is growing. Accordingly, the research and developments in terms of environmental value are progressing steadily now. The main characteristics of environmental products are far-infrared radiation, negative-ion emission, electromagnetic wave shielding, and antimicrobial property. These products are often used in mortar and as spray on the finishing material. Nevertheless, there are hardly any research on the functional properties of concrete, the main material in construction field. Thus, we evaluated such basic properties of concrete as slump, compressive strength and air content while using such functional materials as sericite, wood-pattern sandstone, carbon black and nano-metric silver solution to focus on their functional properties like far-infrared radiation, negative ion emission, electro magnetic wave shielding, and antimicrobial activity in this research. The results indicated that the most useful material in the functional materials was carbon black. Sericite and nano-metric silver solution had a little effect on the functional property. Moreover, although wood-pattern sandstone had very high functional property, it exhibited too low compressive strength to be applied, to concrete as a factory product. Antimicrobial property of nano-metric silver solution in the concrete was not clear demonstrated, but if these specimens were to be aged in $CO_2$ gas for a long time, it might be apparent.

기능성 재료를 사용한 콘크리트의 특성에 관한 연구 (A Research for the Property of the Concrete Using Functional Materials)

  • 이종찬
    • 한국건설순환자원학회논문집
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    • 제2권2호
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    • pp.93-100
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    • 2006
  • Building materials are trending toward environmental materials nowadays and the market share of those is growing. So those researches and developments for environmental property are proceeding now. The main properties of environmental products are far infrared emission, negative ion emission, electro magnetic wave shielding, and anti fungus, these products are used with shape of mortar, and spray on the finish material. But There are not much researches for the concrete, main material in construction field, with those functional properties. So in this research we evaluated slump, compressive strength and air content as basic properties for concrete using functional materials of sericite, wood pattern sand stone, carbon black and nanometric silver solution and functional properties like far infrared emission, negative ion emission, electro magnetic wave shielding, and anti fungus. The results were as follows. The most useful material in the functional materials was carbon black. Sericite and nanometric silver solution had a little effect on functional property, so it was difficult to apply to concrete, and wood pattern sand stone had a high functional property but low compressive strength, can be applied to a factory product. Anti fungus of the concrete using nanometric silver solution was not clear but if those specimens were aged in $CO_2$ gas for a long time it might apparent.

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Periodic Properties of a Lyapunov Functional of State Delay Systems

  • Young Soo Suh
    • KIEE International Transaction on Systems and Control
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    • 제2D권2호
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    • pp.92-96
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    • 2002
  • This paper is concerned with properties of a Lyapunov functional of state delay systems. It is shown that if a state delay system has a pure imaginary pole for some state delay, then no Lyapunov functional satisfying a Lyapunov condition exists periodically with respect to change of the state delay. This periodic property is unique in state delay systems and has been well known in the frequency domain stability conditions. However, in the time domain stability conditions using a Lyapunov functional, the periodic property is not known explicitly.

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파래 추출액을 이용한 지사용 원지와 직물의 천연 염색성 및 기능성에 관한 연구 (A Study for Natural Dyeing and Functional Property of Paper and Fabrics with Green Laver Extracts)

  • 김기훈;강술생;임현아
    • 한국생활과학회지
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    • 제23권5호
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    • pp.861-871
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    • 2014
  • This study explored applicability of natural dyeing and functional property of base paper using paper yarn and fabrics with green laver extracts. As a result of measuring dyeability and functional property of cotton, silk, and a blended fabric of cotton/mulberry, $60^{\circ}C$ and 40 minutes was the optimal dyeing condition for the cotton fabric under an alkali condition; $50^{\circ}C$ and 60 minutes for the silk fabric; $60^{\circ}C$ and 50 minutes for the blended fabric of cotton/mulberry. As a result of measuring the color fastness after dyeing cotton, silk and the blended fabric of cotton/mulberry, fastness to washing, water, rubbing, dry cleaning and light was superior. In terms of functional property, the silk and the blended fabric of cotton/mulberry were superior concerning antimicrobial properties of the fabric dyed with green laver extracts while the cotton fabric showed 90% or over. Regarding deodorization, the blended fabric of cotton/mulberry was the most superior. All the fabrics were harmless to the human body as they had heavy metal content below the standard. Considering the research results comprehensively, the green laver extracts possibly has enough applicability and functional property as a natural dyes. Moreover, it has potential to be developed new eco-friendly fashion materials.

패션과 건축에 표현된 기능주의적 미니멀리즘 비교 (Comparison of the Functional Minimalism in Fashion and Architecture)

  • 박선지;임은혁
    • 한국의류학회지
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    • 제37권3호
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    • pp.247-259
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    • 2013
  • This study conceptually approaches and clearly compares the similarities and differences of fashion and architecture through a focus on their correlations. This study identifies the conceptual definitions of functional minimalism by an examination of function that represents the largest similarity between architecture and fashion. This study classifies the nature of functional minimalism and studies cases for each architectural classification in the areas of: the simplicity of a structure, unitarity pursuit of economic value, repeatability in an efficiency unit, reducibility stressing property, and multi-functional spatiality. The characteristics of functional minimalism fashion are distinguish as: simplicity in a structure that highlight structural lines in non-decorated design, unitarity pursuit of economic value represented in united process and pattern for its economic effect, repeatability in an efficiency unit represented through the repeated decoration of a functional unit, reducibility stressing a property that emphasizes property with a dominant design element through a highlight of the characteristics of materials and multi-functional spatiality that represents variability in clothes through an expansion of limited spatial function. This study approaches each discipline with a clear understanding of the differences between the two and suggests standards for a comparative study of architecture and fashion.

Functional central limit theorems for ARCH(∞) models

  • Choi, Seunghee;Lee, Oesook
    • Communications for Statistical Applications and Methods
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    • 제24권5호
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    • pp.443-455
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    • 2017
  • In this paper, we study ARCH(${\infty}$) models with either geometrically decaying coefficients or hyperbolically decaying coefficients. Most popular autoregressive conditional heteroscedasticity (ARCH)-type models such as various modified generalized ARCH (GARCH) (p, q), fractionally integrated GARCH (FIGARCH), and hyperbolic GARCH (HYGARCH). can be expressed as one of these cases. Sufficient conditions for $L_2$-near-epoch dependent (NED) property to hold are established and the functional central limit theorems for ARCH(${\infty}$) models are proved.

키토산 처리한 폴리에스테르 편평사 직물의 고기능화 가공에 관한 연구 (A Study on the High Functional Finishing of Polyester Flat Fabrics Treated with Chitosan)

  • 이석영;박성우;김삼수
    • 한국염색가공학회지
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    • 제16권3호
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    • pp.22-30
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    • 2004
  • The polyester fabrics were treated with the chitosan with various solubility in optimized treatment condition. The treatment method was discussed to be a high functional finishing for the polyester fabric to obtain the high moisture absorption and anti-microorganism property by evaluating the effect of the chitosan purification method on the yield and anti-microorganism property of the chitosan. On the other hand, soluble polyurethane was added to the chitosan treatment solution and/or plasma pretreatment was done. The addition of soluble polyurethane give a high add-on ratio as well as a linen like effect of treated polyester fabric. The results were as follows: 1. In the treatment of polyester fabric by the chitosan solution, a soluble PU resin and low temperature plasma treatment were done to obtain high binding force between the fabrics and the chitosan. The add-on rate and the moisture absorption ratio of the fabrics treated with the chitosan-PU after treated with the plasma slightly increased more than those of the fabrics treated with the chitosan only. 2. Anti-static property of the fabrics treated with the chitosan decreased rapidly with increasing of the chitosan concentration. The washing fastness of the fabrics treated with the chitosan-PU after treated with the plasma was better than those of the fabrics treated with chitosan only. The wrinkle resistance of the treated fabrics decreased constantly with the concentration of the chitosan. The bending rigidity of the treated fabrics increased greatly. On the treatment of polyester fabric under optimum condition, the microorganism reduction rate kept above 90% after 10times launderings. 3. As the polyester fabrics which has flat yam was used as a weft yams were treated with the chitosan-PU as give a functional finishing effects such as durability, moisture absorption, anti-static and anti- microorganism property. Treated polyester fabric showed a good functional finishing effect and a linen like property.

초등학교 5학년 학생들의 일반화된 산술 관점과 함수적 관점에서의 변수에 대한 이해 (Fifth Graders' Understanding of Variables from a Generalized Arithmetic and a Functional Perspectives)

  • 방정숙;김리나;곽은애
    • 한국수학교육학회지시리즈E:수학교육논문집
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    • 제37권3호
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    • pp.419-442
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    • 2023
  • 본 연구는 초기 대수의 일반화된 산술 관점과 함수적 관점에서 초등학교 5학년 학생들의 변수에 대한 이해 실태를 조사하였다. 구체적으로 전자에서는 1의 성질, 덧셈의 교환법칙, 곱셈의 결합법칙, 산술 맥락에서의 문제 상황을 포함하였고, 후자에서는 덧셈 관계, 곱셈 관계, 제곱 관계, 선형 관계를 다루었다. 11개 학교에서 246명의 학생들을 대상으로 조사한 결과, 학생들은 공통적으로 변수에 해당하는 특정한 값을 구할 수 있었고, 변수를 활용한 식에서 다른 기호를 사용하여 식을 바꿔 쓸 수도 있다는 점을 이해하는 것으로 드러났다. 그러나 정해지지 않은 양을 포함한 산술 맥락에서의 문제 상황을 변수를 활용하여 일반화된 식으로 나타내는 데 많은 어려움을 겪었다. 또한 1의 성질과 덧셈의 교환법칙을 나타낸 식에서 변수는 자연수만 된다고 생각하는 경향이 있었으며, 약 25%의 학생들은 변수가 한 가지 수로 정해져 있다고 생각하였다. 이와 같은 연구 결과를 바탕으로 본 논문은 초등학생들의 변수 이해 및 지도에 대한 시사점을 제시하였다.

ON SOME SOLUTIONS OF A FUNCTIONAL EQUATION RELATED TO THE PARTIAL SUMS OF THE RIEMANN ZETA FUNCTION

  • Martinez, Juan Matias Sepulcre
    • 대한수학회보
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    • 제51권1호
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    • pp.29-41
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    • 2014
  • In this paper, we prove that infinite-dimensional vector spaces of -dense curves are generated by means of the functional equations f(x)+f(2x)+${\cdots}$+f(nx) = 0, with $n{\geq}2$, which are related to the partial sums of the Riemann zeta function. These curves ${\alpha}$-densify a large class of compact sets of the plane for arbitrary small ${\alpha}$, extending the known result that this holds for the cases n = 2, 3. Finally, we prove the existence of a family of solutions of such functional equation which has the property of quadrature in the compact that densifies, that is, the product of the length of the curve by the $n^{th}$ power of the density approaches the Jordan content of the compact set which the curve densifies.

UNIFORMLY LIPSCHITZ STABILITY AND ASYMPTOTIC PROPERTY OF PERTURBED FUNCTIONAL DIFFERENTIAL SYSTEMS

  • Im, Dong Man;Goo, Yoon Hoe
    • Korean Journal of Mathematics
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    • 제24권1호
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    • pp.1-13
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    • 2016
  • This paper shows that the solutions to the perturbed functional dierential system $$y^{\prime}=f(t,y)+{\int_{t_0}^{t}}g(s,y(s),Ty(s))ds$$ have uniformly Lipschitz stability and asymptotic property. To sRhow these properties, we impose conditions on the perturbed part ${\int_{t_0}^{t}}g(s,y(s),Ty(s))ds$ and the fundamental matrix of the unperturbed system $y^{\prime}=f(t,y)$.