• Title/Summary/Keyword: function rings

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Topology and geometry optimization of different types of domes using ECBO

  • Kaveh, A.;Rezaei, M.
    • Advances in Computational Design
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    • v.1 no.1
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    • pp.1-25
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    • 2016
  • Domes are architectural and elegant structures which cover a vast area with no interrupting columns in the middle, and with suitable shapes can be also economical. Domes are built in a wide variety of forms and specialized terms are available to describe them. According to their form, domes are given special names such as network, lamella, Schwedler, ribbed, and geodesic domes. In this paper, an optimum topology design algorithm is performed using the enhanced colliding bodies optimization (ECBO) method. The network, lamella, ribbed and Schwedler domes are studied to determine the optimum number of rings, the optimum height of crown and tubular sections of these domes. The minimum volume of each dome is taken as the objective function. A simple procedure is defined to determine the dome structures configurations. This procedure includes calculating the joint coordinates and element constructions. The design constraints are implemented according to the provision of LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Constitution). The wind loading act on domes according to ASCE 7-05 (American Society of Civil Engineers). This paper will explore the efficiency of various type of domes and compare them at the first stage to investigate the performance of these domes under different kind of loading. At the second stage the wind load on optimum design of domes are investigated for Schwedler dome. Optimization process is performed via ECBO algorithm to demonstrate the effectiveness and robustness of the ECBO in creating optimal design for domes.

A GENERALIZATION OF THE PRIME RADICAL OF IDEALS IN COMMUTATIVE RINGS

  • Harehdashti, Javad Bagheri;Moghimi, Hosein Fazaeli
    • Communications of the Korean Mathematical Society
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    • v.32 no.3
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    • pp.543-552
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    • 2017
  • Let R be a commutative ring with identity, and ${\phi}:{\mathfrak{I}}(R){\rightarrow}{\mathfrak{I}}(R){\cup}\{{\varnothing}\}$ be a function where ${\mathfrak{I}}(R)$ is the set of all ideals of R. Following [2], a proper ideal P of R is called a ${\phi}$-prime ideal if $x,y{\in}R$ with $xy{\in}P-{\phi}(P)$ implies $x{\in}P$ or $y{\in}P$. For an ideal I of R, we define the ${\phi}$-radical ${\sqrt[{\phi}]{I}}$ to be the intersection of all ${\phi}$-prime ideals of R containing I, and show that this notion inherits most of the essential properties of the usual notion of radical of an ideal. We also investigate when the set of all ${\phi}$-prime ideals of R, denoted $Spec_{\phi}(R)$, has a Zariski topology analogous to that of the prime spectrum Spec(R), and show that this topological space is Noetherian if and only if ${\phi}$-radical ideals of R satisfy the ascending chain condition.

Ciphertext policy attribute-based encryption supporting unbounded attribute space from R-LWE

  • Chen, Zehong;Zhang, Peng;Zhang, Fangguo;Huang, Jiwu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.4
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    • pp.2292-2309
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    • 2017
  • Ciphertext policy attribute-based encryption (CP-ABE) is a useful cryptographic technology for guaranteeing data confidentiality but also fine-grained access control. Typically, CP-ABE can be divided into two classes: small universe with polynomial attribute space and large universe with unbounded attribute space. Since the learning with errors over rings (R-LWE) assumption has characteristics of simple algebraic structure and simple calculations, based on R-LWE, we propose a small universe CP-ABE scheme to improve the efficiency of the scheme proposed by Zhang et al. (AsiaCCS 2012). On this basis, to achieve unbounded attribute space and improve the expression of attribute, we propose a large universe CP-ABE scheme with the help of a full-rank differences function. In this scheme, all polynomials in the R-LWE can be used as values of an attribute, and these values do not need to be enumerated at the setup phase. Different trapdoors are used to generate secret keys in the key generation and the security proof. Both proposed schemes are selectively secure in the standard model under R-LWE. Comparison with other schemes demonstrates that our schemes are simpler and more efficient. R-LWE can obtain greater efficiency, and unbounded attribute space means more flexibility, so our research is suitable in practices.

The analysis of the characteristic types of motion recognition smart clothing products (동작인식 스마트 의류제품의 특징적 유형 분석)

  • Im, Hyobin;Ko, Hyun Zin
    • The Research Journal of the Costume Culture
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    • v.25 no.4
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    • pp.529-542
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    • 2017
  • The purpose of this study is to utilize technology as basic data for smart clothing product research and development. This technology can recognize user's motion according to characteristics types and functions of wearable smart clothing products. In order to analyze the case of motion recognition products, we searched for previous research data and cases referred to as major keywords in leading search engines, Google and Naver. Among the searched cases, information on the characteristics and major functions of the 42 final products selected on the market are examined in detail. Motion recognition for smart clothing products is classified into four body types: head & face, body, arms & hands, and legs & feet. Smart clothing products was developed with various items, such as hats, glasses, bras, shirts, pants, bracelets, rings, socks, shoes, etc., It was divided into four functions health care type for prevention of injuries, health monitor, posture correction, sports type for heartbeat and exercise monitor, exercise coaching, posture correction, convenience for smart controller and security and entertainment type for pleasure. The function of the motion recognition smart clothing product discussed in this study will be a useful reference when designing a motion recognition smart clothing product that is blended with IT technology.

Segmental Motions and Associated Dynamic Mechanical Thermal Properties of a Series of Copolymers Based on Poly(hexamethylene terephthalate) and Poly(1,4-cyclohexylenedimethylene terephthalate)

  • Jeong Young-Gyu;Lee Sang-Cheol;Jo Won-Ho
    • Macromolecular Research
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    • v.14 no.4
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    • pp.416-423
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    • 2006
  • The dynamic mechanical thermal properties of poly(hexamethylene terephthalate) (PHT), poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) and their P(HT-co-CT) random copolymers in the amorphous state were examined as a function of temperature and frequency. All the samples exhibited two main relaxation processes in the plot of tan ${\delta}$ versus temperature: the primary ${\alpha}$-relaxation associated with the glass transition and the secondary ${\beta}$-relaxation attributed to the local segmental motions of mostly cyclohexylene rings for PCT and to cooperative motions of methylene, carboxyl, and phenylene groups for PHT. Both ${\alpha}$- and ${\beta}$-relaxation temperatures increased with increasing CT content. The activation energy of the ${\alpha}$-relaxation increased with increasing CT content, whereas that of the ${\beta}$-relaxation decreased. The sub-glassy secondary ${\beta}$-relaxation processes of PCT and PHT were investigated in terms of the cooperativity of main-chain segmental motions.

Dielectric Characteristics in Smectic Phase

  • Song, Jun-Ho;Coi, Suck;Kim, Yong-Bae;Kumar, Satyendra;Souk, Jun-Hyung;Shin, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.419-422
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    • 2002
  • We have studied dielectric properties in the smectic phases of 4-(6-ethoxy-1-trifluoromethyl-hexyloxycarbonyl)-phenyl-4-Nonyloxybiphenyl-4-carboxylat ( TFMEOHPNBC ) having fluorine attached to one of its benzene rings. Homogeneous and homeotropic 1.5 and 5${\mu}m$ thick test cells were prepared to analyze molecular dynamic property. We measured capacitance as a function of temperature in the frequency range between 20 Hz and 100 kHz by using HP4284A LCR meter. We observed that the homogeneous cell has high dielectric constant causing dipole moment in smectic $C^{\ast}$ phase, but we can see the dipole moments are canceled out in antiferroelectric phase. It is found that there are two kind of the relaxation director fluctuation below 100 kHz. The first is ionic or space charge contribution below 10 Hz, and the second is Goldstone mode near 1-2 kHz. We will discuss molecular dynamics in smectic phase from extra information such as x-ray and electrooptic data.

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Smectic Layer Reorientation Induced by AC Field

  • Song, Jun-Ho;Kim, Yong-Bae;Kumar, Satyendra;Souk, Jun-Hyung;Shin, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.415-418
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    • 2002
  • We have studied electro-optic properties and layer deformations in the smectic phases of 4-(6ethoxy-l-trifluoromethyl-hexyloxycarbonyl)-phenyl-4-Nonyloxybiphenyl-4-carboxylat ( TFMEOHPNBC ) having fluorine attached to one of its benzene rings by electro-optical and small angle x-ray scattering techniques. 3 and 5${\mu}m$ thick test cells were prepared using beryllium plates to minimize x-ray beam absorption. Layer structure and orientation was studied while changing the amplitude and frequency of the applied electric field as a function of cell temperature. We observed that the chevron layer tilt angle is reduced and layer spacing is increased as stabilizing in antiferroelectric phase. This result is extraordinary that there is dimerization in antiferroelectric phase. We also found that there is a threshold electric field that changes the chevron structure to bookshelf structure. This threshold electric field depends on the frequency and temperature as shown in Fig.1. We will discuss the dynamics of layer orientation as determined from the x-ray, electro-optic and dielectric spectroscopy.

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Effect of age on endothelial function in rat aorta

  • 정이숙;조태순;신화섭
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.90-90
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    • 1995
  • The Influence of age on the endothelial modulation of angiotensin II (AII)-induced contractile response was investigated in isolated aortic rings of rats ranging in age from 0.7 to 20 months. Hemoglobin and L-NAME were used to examine whether age-related changes in the EDRF-releasing system were involved in endothelial modulation of All-induced contraction in rat aorta. In all five age groups (0.7, 1.5, 3, 6, 20 months), hemoglobin (10 ${\mu}$M) significantly enhanced All-induced contractile response only in aorta with endothelium intact. L-NAME (10 ${\mu}$M) Produced a significant enhancement in All responses in endothelium-intact aortas from rats aged 0.7 and 1.5 months, but it had no effect in aortas from older rats aged 6 and 20 months. Indomethacin (10 ${\mu}$M) did not affect All-induced contractile responses in both endothelium intact and removed aortas from rats at the age of 0.7 to 20 months. Hemoglobin (10 ${\mu}$M) abolished acetylcholine-induced relaxation response in aortas from young and old rats. L-NAME completely abolished the relaxation in aortas from young (0.7 and 1.5 months), but incompletely in aortas from older (6 and 20 months) rats. The sensitivity of endothelium-dependent relaxation to A23187 increased with age between ages of 0.7 and 6 months, with no further increase noted up to 20 months of age. These results suggest that endothelial modulation of AII-induced contraction in rat aorta might involve age-related alteration in EDRF-releasing system, probably via post-receptor mechanism.

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Endothelium-Independent Effect of Fisetin on the Agonist-Induced Regulation of Vascular Contractility

  • Je, Hyun Dong;Sohn, Uy Dong;La, Hyen-Oh
    • Biomolecules & Therapeutics
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    • v.24 no.1
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    • pp.57-61
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    • 2016
  • Fisetin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of fisetin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Fisetin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, fisetin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of fisetin on agonist-induced vascular contraction regardless of endothelial function.

Heat Transfer Analysis of Hydropneumatic Suspension Unit By Finite Element Method (유한요소법을 이용한 유기압 현수장치의 열전달 해석)

  • Bae, Jing-Do;Cho, Jin-Rae;Lee, Hong-Woo;Song, Jung-In;Lee, Jin-Kyoo
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.531-536
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    • 2004
  • In-arm type hydropeumatic suspension unit(ISU) is an equipment of armed tracked vehicle to absorb impact load and vibration from the irregular ground. During the operation of ISU, main piston moves forward and backward and oil flowing through damper transmits the external impact load to floating piston. Heat is generated in ISU by the oil pressure drop through the damper orifice and the friction between cylinder wall and two pistons. On the other hand, internal heat dissipatis outside via heat convection. Occurrence of high temperature can deteriorate durability of major components and basic function of ISU. And, it can cause fatal problem in the ISU life time and the sealing performance of piston rings. As well, the spring constant change of nitrogen gas that is caused by the temperature rise exerts the negative effect to the vehicle stability. Therefore, in this paper, we analyze the heat transfer analysis of the entire ISU unit, by finite element method, with the outside flow velocities 8m/s and 10m/s.

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