Pseudo-Random Sequences Generator Based on Discrete Hyperchaotic Systems

We first design a discrete hyperchaotic system via piece-wise linear state feedback. The states of the closed loop system are locally expanding in two directions but absolutely bounded on the whole, which implies hyperchaos. Then, we use three suchlike hyperchaotic systems with different feedback gain matrices to design a pseudo-random sequence generator (PRSG). Through a threshold function, three sub-sequences generated from the output of piecewise linear functions are changed into 0-1 sequences. Then, followed by XOR operation, an unpredictable pseudo-random sequence (PRS) is ultimately obtained. The analysis and simulation results indicate that the PRS, generated with hyperchaotic systems, has desirable statistical features.

HIERACHICAL STRUCTURES FOR GENERATING PSEUDO-RANDOM SEQUENCES AND ARRAYS

This paper proposes new hierarchical structures for generating pseudorandom sequences and arrays. The principle of the structures is based on a new concept-multi-interleaving. It is the generalization of normal sequence decimation(sampling). The kernal of the structures is a lower speed linear feedback shift register together with several high speed time-division multiplexers arranged hierarchically. These new structures have much higher speed compared with that of other schemes proposed before.

Adding Pseudo-Random Test Sequence Generator in the Test Simulator for DFT Approach

This paper presents modified version of a realistic test tool suitable to Design For Testability （DFT） and Built-ln Self Test （BIST） environments. A comprehensive tool is developed in the form of a test simulator. The simulator is capable of providing a required goal of test for the Circuit Under Test （CUT）. The simulator uses the approach of fault diagnostics with fault grading procedures to provide the optimum tests. The current version of the simulator embeds features of exhaustive and pseudo-random test generation schemes along with the search solutions of cost effective test goals. The simulator provides facilities of realizing all possible pseudo-random sequence generators with all possible combinations of seeds. The tool is developed on a common Personal Computer （PC） platform and hence no special software is required. Thereby, it is a low cost tool hence economical. The tool is very much suitable for determining realistic test sequences for a targeted goal of testing for any CUT. The developed tool incorporates flexible Graphical User Interface （GUI） procedures and can be operated without any special programming skill. The tool is debugged and tested with the results of many bench mark circuits. Further, this developed tool can be utilized for educational purposes for many courses such as fault-tolerant computing, fault diagnosis, digital electronics, and safe-reliable-testable digital logic designs.

PERFECT PUNCTURED BINARY SEQUENCE PAIRS

This paper presents the definition of perfect punctured binary sequence pair and the combinatorial admissible conditions for searching the perfect punctured binary sequence pairs and proves that all of the pseudo-random binary sequences satisfy these conditions. Computer calculation verifies that the pseudo-random binary sequences with length up to N=127 can be easily turned into perfect punctured binary sequence pairs.

Variant Map System to Simulate Complex Properties of DNA Interactions Using Binary Sequences

Stream cipher, DNA cryptography and DNA analysis are the most important R&D fields in both Cryptography and Bioinformatics. HC-256 is an emerged scheme as the new generation of stream ciphers for advanced network security. From a random sequencing viewpoint, both sequences of HC-256 and real DNA data may have intrinsic pseudo-random properties respectively. In a recent decade, many DNA sequencing projects are developed on cells, plants and animals over the world into huge DNA databases. Researchers notice that mammalian genomes encode thousands of large noncoding RNAs (lncRNAs), interact with chromatin regulatory complexes, and are thought to play a role in localizing these complexes to target loci across the genome. It is a challenge target using higher dimensional visualization tools to organize various complex interactive properties as visual maps. The Variant Map System (VMS) as an emerging scheme is systematically proposed in this paper to apply multiple maps that used four Meta symbols as same as DNA or RNA representations. System architecture of key components and core mechanism on the VMS are described. Key modules, equations and their I/O parameters are discussed. Applying the VM System, two sets of real DNA sequences from both sample human (noncoding DNA) and corn (coding DNA) genomes are collected in comparison with pseudo DNA sequences generated by HC-256 to show their intrinsic properties in higher levels of similar relationships among relevant DNA sequences on 2D maps. Sample 2D maps are listed and their characteristics are illustrated under controllable environment. Visual results are briefly analyzed to explore their intrinsic properties on selected genome sequences.

Characteristics of the May 12,2008 Wenchuan M_S8.0 Earthquake Sequence and Discussion on Relevant Problems

The aftershock activity of the May 12, 2008 Wenchuan Ms8.0 Earthquake Sequence shows an obvious segmented feature. Most of the large aftershocks were distributed in the north and south parts of the aftershock zone. Thrusting was dominant with a small amount of strike-slip component in the south part. The aftershock activity decayed gradually, presenting the sequence features of a mainshock-aftershock pattern. The north part was the ending area of the malnshock fracture where strike-slipping was dominant, showing an obvious swarm feature. Therefore it became the major area for large aftershocks. The modulation of the earth tide on aftershock activity is remarkable; most large aftershocks occur during the period of flood and neap tide. The time period around 16：00 was the dominant occurring time for large aftershocks. The p-value, a parameter of modified Omori formula, increases gradually with time, and reaches about 1 at the end. Based on previous study, the sequence patterns, magnitude of maximum aftershock, as well as the duration of aftershock activity has been discussed. The primary results also show that the magnitude difference between the maiushock and the maximum aftershock is proportional to the rupture size of the maiushock for huge earthquakes of about Ms8.0. This means that when the magnitudes of the earthquakes are nearly the same, large rupture size corresponds to sufficient energy release.

Autocorrelation of Sequences Generated by Single Cycle T-Functions

Cryptographic properties of the single cycle T-function's output sequences are investigated.Bounds of autocorrelation functions of the kth coordinate sequence and bounds of state output sequence are calculated respectively.The Maximum Sidelobe Ratio(MSR) of the kth coordinate sequence and the MSR of state output sequence are given respectively.The bounds of autocorrelation functions show that the values of autocorrelation functions are large when shifts are small.Comparisons of the autocorrelations between the state output sequence and coordinate output sequence are illustrated.The autocorrelation properties demonstrate that T-functions have cryptographic weaknesses and the illustration result shows coordinate output sequences have better autocorrelation than that of state output sequences.

Binary Sequences from a Pair of Elliptic Curves

A family of binary sequences were constructed by using an elliptic curve and its twisted curves over finite fields. It was shown that these sequences possess ＂good＂ cryptographie properties of 0-1 distribution, long period and large linear complexity. The results indicate that such se quences provide strong potential applications in cryptography.

Multi-Value Sequence Generated over Sub Extension Field and Its Properties

Pseudo-random sequences with long period, low correlation, high linear complexity, and uniform distribution of bit patterns are widely used in the field of information security and cryptography. This paper proposes an approach for generating a pseudo-random multi-value sequence (including a binary sequence) by utilizing a primitive polynomial, trace function, and k-th power residue symbol over the sub extension field. All our previous sequences are defined over the prime field, whereas, proposed sequence in this paper is defined over the sub extension field. Thus, it’s a new and innovative perception to consider the sub extension field during the sequence generation procedure. By considering the sub extension field, two notable outcomes are: proposed sequence holds higher linear complexity and more uniform distribution of bit patterns compared to our previous work which defined over the prime field. Additionally, other important properties of the proposed multi-value sequence such as period, autocorrelation, and cross-correlation are theoretically shown along with some experimental results.

新型超声快速处理活检标本保存不同年限对DNA质量的影响

背景:新型超声组织处理技术越来越多地被用来进行分子生物学分析,研究新型超声处理不同存储年限组织DNA的质量,对进一步分子检测的标本质控具有重要意义。目的:探讨新型超声处理活检标本存储不同年限对DNA质量的影响,以期为分子检测探索最佳的标本存储时间。方法:收集40例乳腺穿刺小活检组织,采用超声技术制作石蜡标本,按照存储年限分为4组:<1年组、1-3年组、>3-5年组及>5年组,每组10例,对石蜡标本进行切片,每张切片厚3μm,切片10-15张,提取DNA后通过Nanophotometer N60超微量分光光度计和Qubit 4.0荧光计检测DNA的质量浓度,记录A_(260)/A_(280)比值判定DNA的纯度,利用全自动毛细管电泳核酸分析仪(Qsep 100)检测DNA片段完整性,以评估DNA片段的质量。结果与结论:4组样本A_(260)/A_(280)均值在1.8-2.0之间,达到纯度要求,无明显差异。4组样本的DNA质量浓度(Qubit浓度)均值分别为30.39,14.33,2.52,1.95 ng/μL;DNA的平均N/Q比值分别为6.48,14.18,24.56,29.86;DNA质量数均值分别为5.64,1.76,1.24,0.80;大片段占比均值分别为56.08%,17.72%,12.68%,7.90%。PCR检测内控基因Ct均值分别为15.32,17.09,18.39,21.24。与<1年组相比,其余3组DNA浓度显著降低,N/Q比值显著增加,DNA质量数和大片段占比均值显著降低,Ct值升高,差异有显著性意义(P<0.05)。实验结果表明,对于新型超声处理活检标本,应优先选择存储<1年的样本进行日常分子检测,储存3年内的样本可满足二代测序等检测要求,5年内样本仅可尝试进行PCR等检测,存储超过5年的样本不建议进行后续分子检测。

基于深度强化学习的WRSN动态时空充电调度

高效的移动充电调度是构建长生命期、可持续运行的无线可充电传感器网络(WRSN)的关键之一.现有基于强化学习的充电策略只考虑了移动充电调度问题的一个维度,即移动充电器(MC)的路径规划,而忽略了充电调度问题中的另一维度,即充电时长调整,因而仍然存在性能限制.提出一种基于深度强化学习的WRSN动态时空充电调度方法(SCSD),建立充电序列调度和充电时长动态调整的深度强化学习模型.针对移动充电调度中离散的充电序列规划和连续的充电时长调整问题,使用DQN为待充电节点优化充电序列,并基于DDPG计算并动态调整序列中待充电节点的充电时长.通过分别从空间和时间两个维度的优化,在避免节点缺电失效的同时,所提出的SCSD可实现充电性能的有效提高.大量仿真实验结果表明,SCSD与现有的几种有代表性的充电方案相比,其充电性能具有明显的优势.

活化富集对土壤样品微生物菌群组成的影响

地球上的微生物绝大多数仍处于未培养状态。微生物的分离培养有助于新物种资源、新天然产物的发现和应用,也有助于对微生物开展生理生化、代谢潜能、演化和生态功能等方面的基础研究。活化富集对于自然生境中微生物的分离培养至关重要。本研究通过16S rRNA基因V3~V4区扩增子测序和宏基因组测序分析了土壤样品不同培养基(WB、PJ、WB/10和PJ-M)、不同活化时长(1~29 d)和不同活化条件(有氧和厌氧)对微生物活化富集的影响。发现活化培养基、培养条件和活化时间的不同会显著影响活化富集后样品的菌群组成。其中,采用营养成分浓度相对较低的培养基(WB/10)、延长活化时长(活化5~29 d)有利于提高活化富集后样品微生物群落的多样性,以及CPR等微生物暗物质的活化及检出。对后续微生物,特别是微生物暗物质的分离培养具有一定的指导作用。

余震持时特性对高烈度区渡槽动力响应的影响研究

主震发生后会在短时间内引发多次余震,长持时余震是否会对主震受损后的高烈度区渡槽结构造成额外损伤仍需探讨.以滇中引水工程某典型梁式渡槽为工程实例,建立渡槽-水-支座-支撑结构全耦合有限元模型.基于能量持时的定义,以设计反应谱为基础,从PEER强震数据库中选择长持时和短持时地震动记录来构造主、余震地震序列,对渡槽结构进行非线性动力分析;充分考虑主震作用后渡槽的初始损伤状态,提出了渡槽损伤评价指标,探讨了不同持时的余震对主震受损后渡槽结构动力响应的影响.结果表明:余震持时特性对主震受损渡槽的抗震性能有显著影响,长持时余震对主震受损后渡槽结构造成更严重的累积损伤,在渡槽动力响应分析中不容忽视.因此,在渡槽地震安全评估和抗震设计时,除需考虑余震的频谱特性和幅值外,还应重点考虑持时特性.

交叉口相位自适应信号控制优化方法

目前对交叉口信号控制问题的研究大多基于固定的相位相序方案,或在几种特定的相位相序方案中进行选择,难以适应交通流的时变特性,在交叉口交通流不均衡的情况下无法充分发挥交叉口的运行效率。针对该问题,提出一种交叉口相位自适应信号控制方法。首先根据交叉口交通流之间的冲突关系,构建了交叉口信号相位集。结合信号控制领域知识,形成了对交叉口相位相序方案、绿灯时长方案及相关约束的数学描述。在此基础上,建立了交叉口相位自适应信号控制的双层规划模型。上层规划以车辆的释放量最大为目标,以相位唯一性约束、车流连续性约束、周期完整性约束为约束条件,对相位相序方案进行优化。下层规划以车辆释放效率最大为目标,以车流最小、最大绿灯时长为约束,对相位绿灯时长进行优化,并将结果返回上层规划。通过上、下层之间的交互,实现对相位相序及绿灯时长的同步优化。为验证方法的有效性,在交叉口非饱和、饱和、过饱和状态下,将该方法与定相位控制、NEMA双环相位结构控制、基于排队长度的贪心控制等方法进行了对比。结果表明:在交叉口不同状态下,与其他方法相比,该方法在车辆释放效率、平均停车延误、平均停车次数、交叉口排队长度等方面均表现出一定的优越性。

Blind reconnaissance of the pseudo-random sequence in DS/SS signal with negative SNR

This paper introduces a new theory and algorithm that can be used in blind detection of the carrier wave signal and the pseudo-random sequence of the direct sequence spread spectrum （DS/SS） signal with negative SNR. First, without any a priori knowledge of the DS/SS signal, the carrier wave signal can be detected from DS/SS signal with negative SNR by using stochastic differential equations and energy detection method. Based on this, the pseudo-random sequence can also be blindly detected in DS/SS signal with negative SNR by reducing noise of the nonlinear signal and the algorithm of wavelet multiscale decomposition algorithm. Finally, the computer simulation shows that we can detect the carrier wave signal with SNR=-27 dB and the pseudo-random sequence under error code ratio 10^-4with SNR =-10 dB.

Pseudo-randomness of the fourth class of GSS sequences

This paper discusses pseudo-randomness of a periodic sequence, named the fourth class of GSS sequence. We get the following results: ① Its least period always reaches the maximum (that is, 2n-1). ② Its least period and linear complexity keep robust under single-symbol-substitution. ③ It has good low-degree-auto-correlation feature. ④ It has good short-length-run-distribution.

Pseudo-random sequence generator based on the generalized Henon map

By analysis and comparison of several chaotic systems that are applied to generate pseudo-random sequence, the generalized Henon map is proposed as a pseudo-random sequence generator. A new algorithm is created to solve the problem of non-uniform distribution of the sequence generated by the generalized Henon map. First, move the decimal point of elements in the sequence to the fight; then, cut off the integer; and finally, quantify it into a binary sequence. Statistical test, security analysis, and the application of image encryption have strongly supported the good random statistical characteristics, high linear complexity, large key space, and great sensitivity of the binary sequence.

Chaotic block iterating method for pseudo-random sequence generator

A pseudo-random sequence generator is a basic tool for cryptography. To realize a pseudo-random sequence generator, a new block iterating method using shifter, multiplier, and adder operations has been introduced. By increasing the iteration of the counter and by performing calculations based on the initial value, an approximate pseudo-random sequence was obtained after exchanging bits. The algorithm and the complexity of the generator were introduced. The result obtained from the calculation shows that the self-correlation of the ＂m＂ block sequence is two-valued; the block field value is [0, 2^m - 1 ], and the block period is 2^m＋8 - 1.

Pseudo-Randomness of Certain Sequences of k Symbols with Length pq

The theory of finite pseudo-random binary sequences was built by C. Mauduit and A. Sarkozy and later extended to sequences of k symbols （or k-ary sequences）. Certain constructions of pseudo-random sequences of k symbols were presented over finite fields in the literature. In this paper, two families of sequences of k symbols are constructed by using the integers modulo pq for distinct odd primes p and q. The upper bounds on the well-distribution measure and the correlation measure of the families sequences are presented in terms of certain character sums over modulo pq residue class rings. And low bounds on the linear complexity profile are also estimated.

中国大陆中强地震余震序列的部分统计特征

依据1970年以来记录相对完整的294次5.0级以上地震序列资料,研究中国大陆中强地震余震序列统计特征,探讨序列类型、最大余震震级、强余震活动持续时间等与主震震级及主震断层性质之间的关系.中国大陆孤立型、主余型及多震型地震余震序列分别约占23%、59%及18%.其中走滑型、具有倾滑分量的走滑型、具有走滑分量的倾滑型及逆冲型分别占48%、24%、17%及11%.余震序列1年内最大余震震级与主震震级正相关,但主震震级较低时相对离散,孤立型序列离散程度较高,主余型及多震型序列线性相关性较好.绝大多数序列最大余震均发生在震后200天内,少数具有晚期强余震的序列主要属主余型序列,孤立型及多震型序列通常没有晚期强余震发生.68%的序列1年内最大余震发生在震后10天内,77%发生在震后30天之内,95%发生在震后120天之内.序列最大余震发生时间及5、6级强余震活动持续时间与序列类型及主震震级大小有关,多震型序列最大余震发生最快,孤立型次之、主余型最长.若仅就主余型序列而言,当主震震级较高时最大余震与主震间时间间隔相对较短,主震震级较低时最大余震与主震间时间间隔相对较长.