• 제목/요약/키워드: sub-zero

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Analysis of Contribution to Net Zero of Non-Urban Settlement - For Green Infrastructure in Rural Areas - (비도시 정주지의 탄소중립 기여도 분석 - 농촌지역 그린인프라를 대상으로 -)

  • Lee, Dong-Kyu;An, Byung-Chul
    • Journal of the Korean Institute of Landscape Architecture
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    • 제50권3호
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    • pp.19-34
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    • 2022
  • This study was conducted to provide basic data that can be used when establishing Net Zero policies and implementation plans for non-urban settlements by quantitatively analyzing the Net Zero contribution to green infrastructure in rural areas corresponding to non-urban settlements. The main purpose is to first, systematize green infrastructure in rural areas, secondly derive basic units for each element of green infrastructure, and thirdly quantify and present the impact on Net Zero in Korea using these. In this study, CVR(Content Validity Ration) analysis was performed to verify the adequacy of green infrastructure elements in rural areas derived through research and analysis of previous studies, is as follows. First, Hubs of Green infrastructure in rural area include village forests, wetlands, farm land, and smart farms with a CVR value of .500 or higher. And Links of Green infrastructure in rural area include streams, village green areas, and LID (rainwater recycling). Second, the basic unit for each green infrastructure element was presented by classifying it into minimum, maximum, and median values using the results of previous studies so that it could be used for spatial planning and design for Net Zero. Third, when Green infrastructure in rural areas is applied to non-urban settlements in Korea, it is analyzed that it has the effect of indirectly reducing CO2 by at least 70.76 million tons and up to 141.16 million tons. This is 3.4 to 6.7 times the amount of CO2 emission from the agricultural sector in 2019, and it can be seen that the contribution to Net Zero is very high. It is expected to greatly contribute to the transformation of the ecosystem. This study quantitatively presented the carbon-neutral contribution to settlements located in non-urban areas, and by deriving the carbon reduction unit for each element of green infrastructure in rural areas, it can be used in spatial planning and design for carbon-neutral at the village level. It has significance as a basic research. In particular, the basic unit of carbon reduction for each green infrastructure factors will be usable for Net Zero policy at the village level, presenting a quantitative target when establishing a plan, and checking whether or not it has been achieved. In addition, based on this, it will be possible to expand and apply Net Zero at regional and city units such as cities, counties, and districts.

SOME Lq INEQUALITIES FOR POLYNOMIAL

  • Chanam, Barchand;Reingachan, N.;Devi, Khangembam Babina;Devi, Maisnam Triveni;Krishnadas, Kshetrimayum
    • Nonlinear Functional Analysis and Applications
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    • 제26권2호
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    • pp.331-345
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    • 2021
  • Let p(z)be a polynomial of degree n. Then Bernstein's inequality [12,18] is $${\max\limits_{{\mid}z{\mid}=1}}\;{\mid}p^{\prime}(z){\mid}\;{\leq}\;n\;{\max_{{\mid}z{\mid}=1}{\mid}(z){\mid}}$$. For q > 0, we denote $${\parallel}p{\parallel}_q=\{{\frac{1}{2{\pi}}}{\normalsize\displaystyle\smashmargin{2}{\int\nolimits_{0}}^{2{\pi}}}\;{\mid}p(e^{i{\theta}}){\mid}^qd{\theta}\}^{\frac{1}{q}}$$, and a well-known fact from analysis [17] gives $${{\lim_{q{\rightarrow}{{\infty}}}}\{{\frac{1}{2{\pi}}}{\normalsize\displaystyle\smashmargin{2}{\int\nolimits_{0}}^{2{\pi}}}\;{\mid}p(e^{i{\theta}}){\mid}^qd{\theta}\}^{\frac{1}{q}}={\max\limits_{{\mid}z{\mid}=1}}\;{\mid}p(z){\mid}$$. Above Bernstein's inequality was extended by Zygmund [19] into Lq norm by proving ║p'║q ≤ n║p║q, q ≥ 1. Let p(z) = a0 + ∑n𝜈=𝜇 a𝜈z𝜈, 1 ≤ 𝜇 ≤ n, be a polynomial of degree n having no zero in |z| < k, k ≥ 1. Then for 0 < r ≤ R ≤ k, Aziz and Zargar [4] proved $${\max\limits_{{\mid}z{\mid}=R}}\;{\mid}p^{\prime}(z){\mid}\;{\leq}\;{\frac{nR^{{\mu}-1}(R^{\mu}+k^{\mu})^{{\frac{n}{\mu}}-1}}{(r^{\mu}+k^{\mu})^{\frac{n}{\mu}}}\;{\max\limits_{{\mid}z{\mid}=r}}\;{\mid}p(z){\mid}}$$. In this paper, we obtain the Lq version of the above inequality for q > 0. Further, we extend a result of Aziz and Shah [3] into Lq analogue for q > 0. Our results not only extend some known polynomial inequalities, but also reduce to some interesting results as particular cases.

Magnetic Properties of TmFe2O4

  • Kim, J.;Lee, B.W.
    • Journal of Magnetics
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    • 제15권1호
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    • pp.29-31
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    • 2010
  • We studied the magnetic properties of $TmFe_2O_4$. The magnetization measurements revealed the magnetic ordering of Fe spins at around 240 K. The difference between zero-field-cooled (ZFC) and field-cooled (FC) magnetization was close to the thermoremanent magnetization (TRM), indicating the glass behavior exhibited by this material.

ANNIHILATOR IDEALS OF SIMPLE MODULES OF RESTRICTED QUANTIZED ENVELOPING ALGEBRA

  • Yu Wang
    • Bulletin of the Korean Mathematical Society
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    • 제60권4호
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    • pp.1025-1034
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    • 2023
  • Let U be the restricted quantized enveloping algebra Ũq(𝖘𝖑2) over an algebraically closed field of characteristic zero, where q is a primitive 𝑙-th root of unity (with 𝑙 being odd and greater than 1). In this paper we show that any indecomposable submodule of U under the adjoint action is generated by finitely many special elements. Using this result we describe all ideals of U. Moreover, we classify annihilator ideals of simple modules of U by generators.

Structure and Microwave Dielectric Characteristics of Ba6-3x(Sm1-yNdy)8+2x(Ti0.95Sn0.05)18O54 Ceramics as a Function Of Sintering Time

  • Li, Yi;Chen, Xiang Ming
    • Journal of the Korean Ceramic Society
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    • 제40권4호
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    • pp.360-364
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    • 2003
  • Effects of sintering time upon the structures and microwave dielectric characteristics of co-substituted $Ba_{6-3x}$/S $m_{8+}$2x/ $Ti_{18}$ $O_{54}$ ceramics (x=2/3) were investigated. Prolonged sintering had significant effects upon the qf value and temperature coefficient, and a high Qf value (10,600 GHz) was obtained in the present ceramics combined with high-$\varepsilon$ (80) and near-zero temperature coefficient.t..

MEROMORPHIC SOLUTIONS OF SOME NON-LINEAR DIFFERENCE EQUATIONS WITH THREE EXPONENTIAL TERMS

  • Min-Feng Chen;Zong-Sheng Gao;Xiao-Min Huang
    • Bulletin of the Korean Mathematical Society
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    • 제61권3호
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    • pp.745-762
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    • 2024
  • In this paper, we study the existence of finite order meromorphic solutions of the following non-linear difference equation fn(z) + Pd(z, f) = p1eα1z + p2eα2z + p3eα3z, where n ≥ 2 is an integer, Pd(z, f) is a difference polynomial in f of degree d ≤ n - 2 with small functions of f as its coefficients, pj (j = 1, 2, 3) are small meromorphic functions of f and αj (j = 1, 2, 3) are three distinct non-zero constants. We give the expressions of finite order meromorphic solutions of the above equation under some restrictions on αj (j = 1, 2, 3). Some examples are given to illustrate the accuracy of the conditions.

SOME RESULTS CONCERNED WITH HANKEL DETERMINANT FOR 𝓝 (𝜶) CLASS

  • Atli, Gizem;Ornek, Bulent Nafi
    • Communications of the Korean Mathematical Society
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    • 제36권4호
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    • pp.715-727
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    • 2021
  • In this paper, we give some results an upper bound of Hankel determinant of H2(1) for the classes of 𝓝 (𝜶). We get a sharp upper bound for H2(1) = c3 - c22 for 𝓝 (𝜶) by adding z1, z2, …, zn zeros of f(z) which are different than zero. Moreover, in a class of analytic functions on the unit disc, assuming the existence of angular limit on the boundary point, the estimations below of the modulus of angular derivative have been obtained. Finally, the sharpness of the inequalities obtained in the presented theorems are proved.

Ni Foam-Supported Ni Nanoclusters for Enhanced Electrocatalytic Oxygen Evolution Reaction

  • Hoeun Seong;Jinhee Kim;Kiyoung Chang;Hyun-woo Kim;Woojun Choi;Dongil Lee
    • Journal of Electrochemical Science and Technology
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    • 제14권3호
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    • pp.243-251
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    • 2023
  • Developing oxygen evolution reaction (OER) electrocatalysts is essential to accomplish viable CO2 and water electrolysis. Herein, we report the fabrication and OER performance of Ni-foam (NF)-immobilized Ni6 nanoclusters (NCs) (Ni6/NF) prepared by a dip-coating process. The Ni6/NF electrode exhibited a high current density of 500 mA/cm2 for the OER at an overpotential as low as 0.39 V. Ni6/NF exhibited high durability in an alkaline solution without corrosion. Electrokinetic studies revealed that OER can be easily initiated on Ni6 NC with fast electron-transfer rates. Finally, we demonstrated stable CO2-to-CO electroreduction using an NC-based zero-gap CO2 electrolyzer operated at a current density of 100 mA/cm2 and a full-cell potential of 2.0 V for 12 h.

Link Scheduling Method Based on CAZAC Sequence for Device-to-Device Communication (D2D 통신 시스템을 위한 CAZAC 시퀀스 기반 링크 스케줄링 기법)

  • Kang, Wipil;Hwang, Won-Jun;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제38A권4호
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    • pp.325-336
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    • 2013
  • FlashLinQ, one of the typical D2D communication systems developed by Qualcomm, considers a single-tone communication based distributed channel-aware link scheduling method to realize the link scheduling process with low control overheads. However, considering the frequency selective fading effect of practical multi-path channel, the single-tone based SIR estimation causes a critical scheduling error problem because the received single-tone signal has quite different channel gain at each sub-carrier location. In order to overcome this problem, we propose a novel link scheduling method based on CAZAC (Constant Amplitude Zero Auto-Correlation) sequence for D2D communication system. In the proposed method, each link has a unique offset value set for the generation of CAZAC sequences. CAZAC sequences with the cyclic offsets are transmitted using multiple sub-blocks in the entire bandwidth, and then each device can obtain nearly full-band SIR using a good cyclic cross-correlation property of CAZAC sequence.