• Title/Summary/Keyword: bent function

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On p-ary Bent Functions Defined on Finite Fields (유한체 상에서 정의된 p진 Bent 함수)

  • 김영식;장지웅;노종선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.6C
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    • pp.763-769
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    • 2004
  • It is known that a bent function corresponds to a perfect nonlinear function, which makes it difficult to do the differential cryptanalysis in DES and in many other block ciphers. In this paper, for an odd prime p, quadratic p-ary bent functions defined on finite fields are given from the families of p-ary sequences with optimal correlation properly. And quadratic p-ary bent functions, that is, perfect nonlinear functions from the finite field F $_{p^{m}}$ to its prime field $F_{p}$ are constructed by using the trace functions. trace functions.

MACWILLIAMS-TYPE IDENTITIES ON VECTORIAL BOOLEAN FUNCTIONS WITH BENT COMPONENTS AND APPLICATIONS

  • Jong Yoon Hyun
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.3
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    • pp.561-574
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    • 2023
  • In this paper, we focus on establishing the MacWilliams-type identities on vectorial Boolean functions with bent component functions. As their applications, we provide a bound for the non-existence of vectorial dual-bent functions with prescribed minimum degree, and several Gleason-type theorems are presented as well.

Generalized Binary Bent Sequences (일반화된 이진 Bent 시퀀스)

  • Gil, Gang-Mi;No, Jong-Seon;Shin, Dong-Joon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.1A
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    • pp.35-41
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    • 2002
  • In this paper, we generalize the family of binary bent sequences introduced by Olsen, Scholtz and Welch [2] to obtain the generalized binary bent sequences with optimal correlation and balance properties. The modified trace transform is introduced and it enables us to use linear function from ${F_{2^n}}$ to the intermediate field ${F_{2^e}}$, where e|n. If we choose e=1, our method becomes the conventional binary bent sequence case. Also, some examples are given which show that our construction gives the family of simple binary sequences with optimal correlation and balance properties.

A Study on Development of Bent Chair Using Dyed-Glued Laminated Wood (염색집성목을 이용한 곡목의자의 개발에 관한 연구)

  • Kim, Dong Kooi
    • Journal of the Korea Furniture Society
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    • v.24 no.3
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    • pp.273-285
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    • 2013
  • The bent wood technique has been used for making the bow, the musical instruments and the wagon wheel, The Winsor chair of England in 1730's was the first Lfurniture product by using this method. This method was spread out by Michael Thonet in Austria after the Industrial Evolution. Early making technique of Winsor chair was relatively easy, but Michael Thonet's bent chair was mass produced by the machine and launched the revolution in the industrial furniture. 20th-Century European furniture designers applied the method of layering and forming plywood to bent chairs, enhanced the function and conformability. The bent chair had a big impact on modern chair design. The bent chair has the formative beauty and convenience from the character of softness and colors of wooden materials and has been developed variously by furniture designers. This study is a new approach to use Dyed-Gathered Wood with various colors and patterns as a material of the bend wood. First, bent wood with the Dyed-Gathered Wood enhances a close texture of wooden material textures instead of coating the surface. Second, flexibility of the bent wood with the Dyed-Gathered Wood enables wood bending techniques. Lastly, the Dyed-Gathered Wood is made with relatively cheap woods, replaces expensive imported woods which cause product price rise. This method enables a material cost saving and a stable supply of material.

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On the Cryptogeaphic Signigicance of Bent Functions (Bent 함수의 암호학적 성질에 관한 고찰)

  • 김광조
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.1 no.1
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    • pp.85-90
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    • 1991
  • After we introduce the properties of bent functions satisfying the SAC(Strict Avalanche Criterion), we made cldar the relationship between two functions, i.e., all Boolean functions satisfying the maximum order SAC. Bant function will be useful to implement cryptographic functions like S-boxes of block cipher, nonlinear combiners, etc. But due to thear 0/1 unbalance and their existence for only even number of input bits, bent functions have some restrictions to use as a building block for constructing bijective cryptographic functions.

A Study on the generation and characteristics of Bent codes for Code Division Multiple Access Communication System (부호분할 다중통신 시스템을 위한 Bent 부호발생 및 특성에 관한 연구)

  • 이정재;최삼길;한영열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.2
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    • pp.137-145
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    • 1989
  • In this paper we consider the design of bent sequence generators employing a modified bent function. Through the experimental results and simulation, we show that the period of sequences is $2^n$-1, the number of sequences in the set is $2n/2$, the largest magnitude of correlation is $2n/2$+1, and the sequence generators easy to randomly initialize into any assigned code and hence can be rapidly hopped from sequence to sequence. And we construct a code synchronization system with bent sequence generator as the local code generator, a sliding correlator and DLL as the acquisition subsystem and the tracking subsystem, respectively for DS-CODA, and verify the experimenta results for accomplishing code synchronism.

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Extended Quasi Orthogonal Functions for 3G CDMA Systems (3G CDMA 시스템을 위한 확장 준직교 함수)

  • Lee Kwang-Jae;Moon Myung-Ryong;Hou Jia;Lee Moon-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.7 s.98
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    • pp.697-708
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    • 2005
  • The forward link of the 3G CDMA system may become limited under the increasing of the number of users. The conventional channelization code, Walsh code, has not enough sizes f3r much possible users, therefore, the quasi orthogonal function(QOF), which process optimal crosscorrelation with Walsh code, is considered. In this paper, we investigate quasi orthogonal function on Jacket matrices, which can lead lower correlations values and better performance in 3G CDMA system. Moreover, to simplify the detector and improve the BER performance, a novel detection for QOF CDMA system is proposed. Finally, the simple recursive generation of the bent sequences for QOF mask function is discussed.

The Radiation Patterns of Bent Dipole Antennas (벤트 다이폴 안테나의 복사 패턴)

  • 강민호;문상진
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.19 no.2
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    • pp.7-13
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    • 1982
  • In this Paper, the radiation Patterns of long wire antennas are computed by applying Dyadic Green's Function to the propagation vector, This result is used to analyze the polarized radiation patterns for the various geometrical structures of the bent dipole antennas. When the ratio of the vertical portion over the total length of the bent dipole antenna is 0.4major angle and axail ratio are changed most sensitively for the azimuth rotation, and the radiation field propagates strongly perpendicular to the bent antenna plane.

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On recursively extended Boolean functions (확장 재생성된 부울 함수의 성질)

  • Chee, Seong-Taek;Lee, Sang-Jin;Kim, Kwang-Jo
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.5 no.1
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    • pp.3-16
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    • 1995
  • In this paper, we deal with the cryptographic properties of Boolean functions generated by recursively extended methods from the points of balancedness, nonlinearity and correlation properties. First, we propose a new concept 'Strict Uncorrelated Criterion(SUC)' for two Boolean functions as a necessary condition for constructing Boolean functions of S-box which can be guaranteed to be resistant against Differential cryptanalysis, then we show that the recurively extended Boolean functions with particular form preserve the SUC. We also examine the correlation properties of Boolean functions using Walsh-Hadamard transformations and apply them to discuss nonlinearity, correlation properties and SUC of semi-bent function which is defined over odd dimensional vector space. Finally, we compare semi-bent function with Boolean functions which are generated by other similar recursive methods.

Analysis of Bending Wire Mesh (와이어메쉬 굴곡배치 타당성분석)

  • Kim, Chun-Ho;Jung, Dae-Suk
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.6
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    • pp.169-174
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    • 2009
  • We conducted structural analysis to investigate disadvantage of wire-mesh arranged at the plane and to develop three-dimensionally bent U-type wire-mesh. In all case that distributed loading at the whole top slab and the half top slab, and the wire mesh was bent $45^{\circ}$, flexura tensile stress was the fewest in both positive moment and negative moment, and the wire mesh was bent $45^{\circ}$ in crossway the shear stresss was the fewest. Therefore, by arranging wire-mesh with $45^{\circ}$ more bent than plane, flexura tensile stress, shear stress, displacement will be reduced and structural function will be improved.