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Refined Convergents to the Associated Continued Fractions for Binary Sequences

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Acta Mathematica Sinica,English Series 1994年第2期10卷 179-191页

作者： dai zongduo Zeng Kencheng State Key Laboratory of Information Security Academia Sinica Beijing, 100039 China State Key Laboratory of Information Security Academia Sinica Beijing China

The relation between continued fractions and Berlekamp’s algorithm was studied by some reseachers. The latter is an iterative procedure proposed for decoding BCH codes. However, there remains an unanswered question whether each of the iterative steps in the algorithm can be interpreted in terms of continued fractions. In this paper, we first introduce the so-called refined convergents to the continued fraction expansion of a binary sequence s, and then give a thorough answer to the question in the context of Massey’s linear feedback shift register synthesis algorithm which is equivalent to that of Berlekamp, and at last we prove that there exists a one- to-one correspondence between the n-th refined convergents and the length n segments.

关键词： Refined Convergents to the Associated Continued Fractions for Binary Sequences

Classification and Enumeration of Matched Free Response Matrices of Linear Finite Automata

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Acta Mathematica Sinica,English Series 1997年第1期13卷 133-144页

作者： dai zongduo Ye Dingfeng Zhai Qibin Ou Haiwen (Graduate School of Academia Sinica,Beijing 100039,China) Graduate School of Academia Sinica 100039 Beijing China

If H and G are the transfer function matrix and the free response matrix of a linear finite automaton,then G is called a free response matrix matched to *** H,let(H)be the set of all possible free response matrices ma... 详细信息

关键词： Finite automation Free response matrix Classification Enumeration

A CRYPTOGRAPHIC STUDY ON S-BOXES OF DES TYPE Ⅲ

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Systems Science and Mathematical Sciences 1992年第1期5卷 27-32页

作者： YANG Junhui (Computing Center of Academia Sinica,Beijing 100080,China)dai zongduo ZENG Kencheng (Graduate School of Academia Sinica,Beijing 100039,China)

The so-called selected permutations on the set of the first 16 non-negative integers are classified under the action of a certain motion ***-base consisted of the class representatives has been provided.

关键词： DES S-box

ON THE LINEAR PREDICTABILITY TEST FOR ENCIPHERING SEQUENCES

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Systems Science and Mathematical Sciences 1994年第1期7卷 89-96页

作者： ZENG Kencheng dai zongduo(State Key Laboratory of injormation Security, Academia Silica, Beijing 100039, China)YANG Junhui(Computing Center, Academia Sinica, Beijing 100080, China)

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ＯＮＴＨＥＬＩＮＥＡＲＰＲＥＤＩＣＴＡＢＩＬＩＴＹＴＥＳＴＦＯＲＥＮＣＩＰＨＥＲＩＮＧＳＥＱＵＥＮＣＥＳ￥ＺＥＮＧＫｅｎｃｈｅｎｇ；ＤＡＩＺｏｎｇｄｕｏ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆｉｎｊｏｒｍａｔｉｏｎＳｅｃｕｒｉｔｙ，Ａｃａｄｅｍｉａ...

关键词： Enciphering sequences linear complexity.

POLYNOMIAL REPRESENTATION OF A CLASS OF SEQUENCES

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Chinese Science Bulletin 1987年第10期32卷 649-654页

作者：戴宗铎 such that

Ⅰ. INTRODUCTION Let This is a sequence of period qn over finite field Fq（q=pm, p being a prime）. It is easy to see that there exists a unique polynomial fα(x0, x1,…, xmn-1)∈Fq[x0, x1, …, xmn-1] such

关键词： CLASS polynomial integer generating generalize uniquely expanded write

CONSTRUCTION OF SAC PERMUTATIONS

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Systems Science and Mathematical Sciences 1997年第2期10卷 120-121,123-128页

作者： GONG Guang (Department of Applied Mathematics, University of Electronic Science and Technology of China, Chengdu 610054,China) dai zongduo (State Key Laborotory of Infrmation Security, the Graduate School,Academia Sinica, Beijing 100039, China) 电子科技大学应用数学系四川成都中国科学技术大学北京研究生院信息安全国家重点实验室北京

Nonlinear permutations of GF(2n) with strong cryptographic properties have important applications in cryptology such as DES-like block ciphers, hush functions and stream ciphers. In paPer [1], we proved that the exponential function can provide a class of permutations satisfying the Strict Avalanche Criterion (SAC permutations) with algebraic nonlinear degree 2. In this paper, we further construct three classes of SAC permutations that are derived from the Dickson polynomials, GMW functions and the exponential functions with maximal algebraic nonlinear degree, respectively.

关键词： The Strict Avalanche Criterion Dickson polynomial GMW function exponential function.

NONLINEAR FEEDFORWARD SEQUENCES OF m-SEQUENCES (Ⅲ)

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Systems Science and Mathematical Sciences 1994年第4期7卷 367-370页

作者： dai zongduo(Graduate School,Academia Sinica, Beijing 100039, China)FENG Xuuing(Institute of Mathematics,Academia Sinica, Beijing 100080, China)LIU Mulan WAN Zhexian(Institute of Systems Science, Academia Sinica, Beijing 100080, China)

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ＮＯＮＬＩＮＥＡＲＦＥＥＤＦＯＲＷＡＲＤＳＥＱＵＥＮＣＥＳＯＦｍ－ＳＥＱＵＥＮＣＥＳ（Ⅲ）ＤＡＩＺｏｎｇｄｕｏ（ＧｒａｄｕａｔｅＳｃｈｏｏｌ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，Ｂｅｉｊｉｎｇ１０００３９，Ｃｈｉｎａ）ＦＥＮＧＸｕｕｉｎｇ（Ｉｎｓｔｉｔｕｔ...

关键词： Non-degenerate monomial function congruent monomial function

Near-field wideband beam training for ELAA with uniform circular array

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Science China(Information Sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong dai Department of Electronic Engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 163-178页

作者： Wu Houli Guo Endong Wang Jingyi dai Xin dai Chenxi Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much *** paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame *** material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic *** response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical *** acceleration response and displacement response of different combinations are *** results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes.

关键词： water supply pipe different materials shaking table test amplification factor seismic fragility