• Title/Summary/Keyword: compact section

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Fuzzy Almost Continuous Mappings and Fuzzy Almost Quasi-Compact Mappings

  • Park, Kuo-Duok;Im, Young-Bin;Soung, Goang-Ou
    • Journal of the Korean Institute of Intelligent Systems
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    • v.5 no.1
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    • pp.3-14
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    • 1995
  • In this paper we introduce the class of fuzzy almost contrinuous mappings. It contains the class of fuzzy continuous mappings and is contained in the class of fuzzy weakly continuous mappings. In section 3 we discuss various properties of such mappings. In section 4 we also introduce the notion of fuzzy almost quasi-compact mappings and give relations between fuzzy almost quasi-compact mappings and the mapping which are introduced in section 2 and 3.

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Optimal Design of I-type Girders in 2-Span Continuous Steel Bridges by LRFD (LRFD에 의한 연속보 주부재의 조밀 및 비조밀 단면 최적화 설계)

  • Gook, Joong-Sik;Shin, Yung-Seok
    • Journal of Korean Society of Steel Construction
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    • v.12 no.3 s.46
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    • pp.329-337
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    • 2000
  • The Load and Resistance Factor Design(LRFD) Specification defines two sets of limiting width-to-thickness ratios. On the basis of these limiting values, steel sections are subdivided into three categories: compact, noncompact, and slender sections. In this paper, I-Type girders of a 2 span continuous steel bridge are divided into compact and non-compact sections and analyzed. In the design process, an optimization formulation was adopted and ADS, a Fortran program for Automated Design Synthesis, was used. In this study, we studied about change of the section between compact and non-compact using optimization formulation.

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Treatment of non-resonant spatial self-shielding effect of double heterogeneous region

  • Tae Young Han;Hyun Chul Lee
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.749-755
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    • 2023
  • A new approximation method was proposed for treating the non-resonant spatial self-shielding effects of double heterogeneous region such as the double heterogeneous effect of VHTR fuel compact in the thermal energy range and that of BP compact with BISO. The method was developed based on the effective homogenization method and a spherical unit cell model with explicit coated layers and a matrix layer. The self-shielding factor was derived from the relation between the collision probabilities for a double heterogeneous compact and the effective cross section for the homogenized compact. First, the collision probabilities and transmission probabilities for all layers of the spherical model were calculated using conventional collision probability solver. Then, the effective cross section for the homogenized sphere cell representing the homogenized compact was obtained from the transmission probability calculated using the probability density function of a chord length. The verification calculations revealed that the proposed method can predict the self-shielding factor with a maximum error of 2.3% and the double heterogeneous effect with a maximum error of 200 pcm in the typical VHTR problems with various packing fractions and BP compact sizes.

The effect of beam section property on the behavior of modular prefabricated steel moment connection

  • Kazemi, Seyed Morteza;Sohrabi, Mohammad Reza;Kazemi, Hasan Haji
    • Steel and Composite Structures
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    • v.32 no.6
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    • pp.769-778
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    • 2019
  • The specially prefabricated steel moment connections with pyramid head is one of the significant innovations in the steel structures forms to improve the installation time and simplify the construction procedure. The beams in this structure form are supported by two top and bottom angles and web double angles. Such a configuration despite its advantages increases the welding operation and filed installation time and costs. In this paper, the effect of using beams with channel and I section in three classes of seismically compact, seismically non-compact, and slender section according to width-to-thickness ratio on the behavior of the connection was investigated under monotonic and cyclic loading. Modeling was performed by ABAQUS and verified by the results of an experimental specimen. The findings indicated that using I and channel section instead of angle section reduces the amount of welding materials as well as easing the installation procedure. However, it has no significant effect on the ultimate strength and ductility of the connection. Furthermore, if the beam section is seismically compact, this form is considered as a special moment frame that has a rotation capacity up to 0.04 radians without any reduction in connection moment resistance.

Some generalized weak vector quasivariational-like inequalities for fuzzy mappings

  • Lee Byung-Soo;Cho Hyun-Duk
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.1
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    • pp.70-76
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    • 2006
  • Some Stampacchia type of generalized weak vector quasivariational-like inequalities for fuzzy mappings was introduced and the existence of solutions to them under non-compact assumption was considered using the particular form of the generalized Ky Fan's section theorem due to Park [15]. As a corollary, Stampacchia type of generalized vector quasivariational-like inequalities for fuzzy mappings was studied under compact assumption using Ky Fan's section theorem [7].

Symmetric and Asymmetric Double Gate MOSFET Modeling

  • Abebe, H.;Cumberbatch, E.;Morris, H.;Tyree, V.;Numata, T.; Uno, S.
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.9 no.4
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    • pp.225-232
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    • 2009
  • An analytical compact model for the asymmetric lightly doped Double Gate (DG) MOSFET is presented. The model is developed using the Lambert Function and a 2-dimensional (2-D) parabolic electrostatic potential approximation. Compact models of the net charge and channel current of the DG-MOSFET are derived in section 2. Results for the channel potential and current are compared with 2-D numerical data for a lightly doped DG MOSFET in section 3, showing very good agreement.

Effects of Air Flow Nonuniformity on the Thermal Performance of a Compact Evaporator for Natural Working Fluids (밀집형 자연냉매 증발기의 열성능에 미치는 불균일 공기유동분포의 영향)

  • 박병규;김근오;김무근
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.11
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    • pp.1114-1124
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    • 2001
  • The application of carbon dioxide as an attractive natural working fluid in air cooling and heating system is increasingly important in view of the CFC substitution problem. The thermal performance of compact evaporator was analyzed using section-by-section method. The effects of the two-dimensional nonuniformity of air flow through the evaporator is presented. The detrimental effect of the aid flaw nonuniformity on the thermal performance of the evaporator is found to be significant for many typical applications. It is shown that total heat transfer rate of evaporator using $CO_2$ is higher than that using R134a at the simulation conditions.

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An impulse radio (IR) radar SoC for through-the-wall human-detection applications

  • Park, Piljae;Kim, Sungdo;Koo, Bontae
    • ETRI Journal
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    • v.42 no.4
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    • pp.480-490
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    • 2020
  • More than 42 000 fires occur nationwide and cause over 2500 casualties every year. There is a lack of specialized equipment, and rescue operations are conducted with a minimal number of apparatuses. Through-the-wall radars (TTWRs) can improve the rescue efficiency, particularly under limited visibility due to smoke, walls, and collapsed debris. To overcome detection challenges and maintain a small-form factor, a TTWR system-on-chip (SoC) and its architecture have been proposed. Additive reception based on coherent clocks and reconfigurability can fulfill the TTWR demands. A clock-based single-chip infrared radar transceiver with embedded control logic is implemented using a 130-nm complementary metal oxide semiconductor. Clock signals drive the radar operation. Signal-to-noise ratio enhancements are achieved using the repetitive coherent clock schemes. The hand-held prototype radar that uses the TTWR SoC operates in real time, allowing seamless data capture, processing, and display of the target information. The prototype is tested under various pseudo-disaster conditions. The test standards and methods, developed along with the system, are also presented.

GENERALIZED VECTOR QUASIVARIATIONAL-LIKE INEQUALITIES

  • KANG, MEE-KWANG;LEE, BYUNG-SOO
    • Honam Mathematical Journal
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    • v.26 no.4
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    • pp.533-547
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    • 2004
  • In this paper, we introduce two kinds of generalized vector quasivariational-like inequalities for multivalued mappings and show the existence of solutions to those variational inequalities under compact and non-compact assumptions, respectively.

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NONLINEAR MAPPINGS IN METRIC AND HAUSDORFF SPACES AND THEIR COMMON FIXED POINT

  • Som, Tanmoy
    • Kyungpook Mathematical Journal
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    • v.28 no.1
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    • pp.97-106
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    • 1988
  • In the first section of this paper two common fixed point results for four nonlinear mappings which are pairwise commuting and only two of them being continuous have been given on a complete metric space and on a compact metric space respectively which generalize the results of Mukherjee [2] and Yeh [4]. Further two common fixed point theorems have been established for two finite families of non linear mappings, with only one family being continuous. In another section we extend Theorem 3 and Theorem 4 of Mukherjee [2] for common fixed point of four continuous mappings on a Hausdorff space and on a compact metric space respectively. In the same spaces, these two results have been further generalized for two finite families of continuous mappings.

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