• Title/Summary/Keyword: *-derivation

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CHARACTERIZATIONS OF (JORDAN) DERIVATIONS ON BANACH ALGEBRAS WITH LOCAL ACTIONS

  • Jiankui Li;Shan Li;Kaijia Luo
    • Communications of the Korean Mathematical Society
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    • v.38 no.2
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    • pp.469-485
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    • 2023
  • Let 𝓐 be a unital Banach *-algebra and 𝓜 be a unital *-𝓐-bimodule. If W is a left separating point of 𝓜, we show that every *-derivable mapping at W is a Jordan derivation, and every *-left derivable mapping at W is a Jordan left derivation under the condition W𝓐 = 𝓐W. Moreover we give a complete description of linear mappings 𝛿 and 𝜏 from 𝓐 into 𝓜 satisfying 𝛿(A)B* + A𝜏(B)* = 0 for any A, B ∈ 𝓐 with AB* = 0 or 𝛿(A)◦B* + A◦𝜏(B)* = 0 for any A, B ∈ 𝓐 with A◦B* = 0, where A◦B = AB + BA is the Jordan product.

Continuity of Derivations on Banach Algebras

  • Kim, Gwang Hui
    • Journal of the Chungcheong Mathematical Society
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    • v.6 no.1
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    • pp.65-69
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    • 1993
  • In this paper, we show that the module derivation D is continuous on the Banach algebra and the Silov algebra, and also that the derivation restricted by separating space and the radical on the semi prime Banach algebra is continuous.

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Key Derivation Functions Using the Dual Key Agreement Based on QKD and RSA Cryptosystem (양자키분배와 RSA 암호를 활용한 이중키 설정 키유도함수)

  • Park, Hojoong;Bae, Minyoung;Kang, Ju-Sung;Yeom, Yongjin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.4
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    • pp.479-488
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    • 2016
  • For a secure communication system, it is necessary to use secure cryptographic algorithms and keys. Modern cryptographic system generates high entropy encryption key through standard key derivation functions. Using recent progress in quantum key distribution(QKD) based on quantum physics, it is expected that we can enhance the security of modern cryptosystem. In this respect, the study on the dual key agreement is required, which combines quantum and modern cryptography. In this paper, we propose two key derivation functions using dual key agreement based on QKD and RSA cryptographic system. Furthermore, we demonstrate several simulations that estimate entropy of derived key so as to support the design rationale of our key derivation functions.

A study on the derivation of Dimensionless Unit Hydrographs by the Linear model in the small watersheds (선형 Model에 의한 소류역에 있어서의 무차원 단위도 유도에 관한 연구)

  • 이순혁;한중석
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.23 no.3
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    • pp.78-87
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    • 1981
  • This study was attempted to get dimensionless unit hydrograph by linear model which can be used to the estimation of flood for the development of Agricultural water resources and laid emphasis on the application of dimensionless unit hydrographs for the ungaged watersheds by applying linear model. The results summarized through this study are as follows. 1.Peak discharge is found to be Qp= CAR (C =0. 895A-o.145) having high significance between peak discharge, Qp and effective rainfall, R within the range of small watershed area, 84 to 470km2. consequently, linearity was acknowledged between rainfall and runoff. Reasonability is confirmed for the derivation of dimensionless unit hydrograph by linear model. 2.Through mathematical analysis, formula for the derivation of dimensionless unit hydrograph was derived. qp--p=(tp--t)n-1[e-(n-1)](tp--t-1) 3.Moment method was used for the evaluation of storage constant, K and shape parameter, n for the derivation of dimensionless unit hydrograph. Storage constant, K is more closely related with the such watershed characteristics as length of main stream and slopes. On the other hand, the shape parameter, n was derived with such watershed characteristics as watershed area, river length, centroid distance of the basin and slopes. 4.Time to peak discharge, Tp could be expressed as Tp=1. 25 (√s/L)0.76 having a high significance. 5.Dimensionless unit hydrographs by linear model stood more closely to the observe dimensionless unit hydrographs On the contrary, dimensionless unit hydrographs by S.C. S. method has much difference in comparison with linear model at the falling limb of hydrographs. 6.Relative errors in the q/qp at the point of 0.8 and 1.2 for the dimensionles ratio by linear model and S. C. S. method showed to be 2.41, 1.57 and 4.0, 3.19 percent respectively to the q/qp of observed dimensionless unit hydrographs. 7.Derivation of dimensionless unit hydrograph by linear model can be accomplished by linking the two empirical formulars for storage constant, K, and shape parameter, n with derivation formular for dimensionless unit hydrograph for the ungaged small watersheds.

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