An image encryption algorithm based on spatiotemporal chaos and middle order traversal of a binary tree

This paper proposes an image encryption algorithm based on spatiotemporal chaos and middle order traversal of a binary tree.Firstly,other programming software is used to perform the middle order traversal,and the plaintext image is sorted according to the middle order traversal sequence on the permutation.Secondly,the chaotic sequence is generated using the coupled map lattice to set the chaotic interference value.Finally,the XOR operation between the adjacent pixel values of the replacement image is completed to generate the ciphertext matrix.The simulation and experimental results show that the proposed algorithm can resist typical attacks and has good robustness.

An Improved Approach for Generating Test Cases during Model-Based Testing Using Tree Traversal Algorithm

During the model-based software testing process, test cases are generated from modeled requirements to conduct acceptance testing. However, existing approaches generate erroneous test cases, lack full coverage criteria and prototype tools. Therefore, the aim of this research is to develop an approach capable of reducing erroneous test case generation based on full coverage criteria and a prototype tool. The method employed was to develop a parser to extract information from the XMI file of a modeling diagram where a tree is constructed and a traversal operation executed on the nodes and edges to generate test cases. The results obtained from the proposed approach showed that 97.35% of the generated test cases were precise and comprehensive enough to conduct testing because 99.01% of all the nodes and edges were fully covered during the traversal operations.

Binary Tree’s Recursion Traversal Algorithm and Its Improvement

Binary tree is a very important data structure in computer science. Some major properties are discussed. Both recursive and non-recursive traversal methods of binary tree are discussed in detail. Some improvements in programming are proposed.

DYNAMIC TRAVERSAL CRITERION FOR GEOMETRIC FRACTALS

This paper presents a new generating criterion for self-similar geometric fractalsDynamic Traversal Criterion (DTC) and the principle to practice it. According to the principle,symbol shifting technique is put forward which can control the traversal symbols dynamically in recursive procession. The Dynamic Traversal Criterion inherits the mechanism for generating self-similar fractals from traditional way and creates more fractal images from one initiator and generator than Static traversal strategy.

Fast Single-phase Fault Location Method Based on Community Graph Depth-first Traversal for Distribution Network

With the increasing complexity of distribution network structures originating from the high penetration of renewable energy and responsive loads,fast and accurate fault location technology for distribution networks is a prerequisite for rapid isolation of faults and restoration of the power supply.In this paper,a fault location method based on community graph depth-first traversal is proposed for fast location of single-phase ground faults in distribution networks.First,this paper defines the fault graph weight of the vertices in the distribution network graph model,which can be used to reflect the topology of the vertices and fault points as well as the fluctuation of the vertices’currents.Then,the vertices on the graph model are clustered by using an improved parallel louvain method(IPLM).Finally,the community formed by IPLM is used as the smallest unit for depth-first traversal to achieve fast and accurate location of the fault section.The paper develops a distribution network graph model of IEEE 33-bus system on the graph database for testing.And three other methods are selected for comparison with IPLMDF.The test results show that IPLMDF can achieve fast and accurate fault location when half of the nodes in the distribution network are equipped with D-PMUs.When some of the D-PMUs lose time synchronization,it is still possible to locate the fault section,and at the same time,the locating results can be avoided by falling into local optimal solutions.

On the graph traversal method for evaluating linear binary-chain programs

Grahne et al. have presented a graph algorithm for evaluating a subset of recursive queries. This method consists of two phases. In the first phase, the method transforms a linear binary-chain program into a set of equations over expressions containing predicate symbols. In the second phase, a graph is constructed from the equations and the answers are produced by traversing the relevant paths. A new algorithm is described which requires less time than Grahne’ s. The key idea of the improvement is to reduce the search space that will be traversed when a query is invoked. Further, the evaluation of cyclic data is speeded up by generating most answers directly in terms of the answers already found and the associated 'path information' instead of traversing the corresponding paths as usual. In this way, this algorithm achieves a linear time complexity for both acyclic and most of cyclic data.

Graph Traversal and Top-Down Evaluation of Logic Queries

In this paper, an optimal method to handle cyclic and acyclic data relations in the linear recursive queries is proposed. High efficiency is achieved by integrating graph traversal mechanisms into a top-down evaluation. In such a way the subsumption checks and the identification of cyclic data can be done very efficielltly First, based on the subsumption checks, the search space can be reduced drastically by avoiding any redundant expansion operation. In fact, in the case of non-cyclic data, the proposed algorithm requires only linear time for evaluating a linear recursive query. On the other hand, in the case of cyclic data, by using the technique for isolating strongly connected components a lot of answers can be generated directly in terms of the intermediate results and the relevant path information instead of evaluating them by performing algebraic operations. Since the cost of generating an answer is much less than that of evaluating an answer by algebraic operations, the time consumption for cyclic data can be reduced by an order of magnitude or more.

Z^2 traversal order: An interleaving approach for VR stereo rendering on tile-based GPUs

With increasing demands of virtual reality(VR) applications, efficient VR rendering techniques are becoming essential. Because VR stereo rendering has increased computational costs to separately render views for the left and right eyes, to reduce the rendering cost in VR applications, we present a novel traversal order for tile-based mobile GPU architectures: Z^2 traversal order. In tile-based mobile GPU architectures,a tile traversal order that maximizes spatial locality can increase GPU cache efficiency. For VR applications, our approach improves upon the traditional Z order curve.We render corresponding screen tiles in left and right views in turn, or simultaneously, and as a result, we can exploit spatial adjacency of the two tiles. To evaluate our approach, we conducted a trace-driven hardware simulation using Mesa and a hardware simulator. Our experimental results show that Z^2 traversal order can reduce external memory bandwidth requirements and increase rendering performance.

Noncommutative-Geometry Wormholes Based on the Casimir Effect

While wormholes are as good a prediction of Einstein’s theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, holding a wormhole open requires a violation of the null energy condition, calling for the existence of exotic matter. The Casimir effect has shown that this physical requirement can be met on a small scale, thereby solving a key conceptual problem. The Casimir effect does not, however, guarantee that the small-scale violation is sufficient for supporting a macroscopic wormhole. The purpose of this paper is to connect the Casimir effect to noncommutative geometry, which also aims to accommodate small-scale effects, the difference being that these can now be viewed as intrinsic properties of spacetime. As a result, the noncommutative effects can be implemented by modifying only the energy momentum tensor in the Einstein field equations, while leaving the Einstein tensor unchanged. The wormhole can therefore be macroscopic in spite of the small Casimir effect.

Exploration of Traversable Wormholes Sustained by an Extra Spatial Dimension

The main goal of this paper is to determine the effect of an extra dimension on a traversable wormhole. Here an earlier study by the author [Phys. Rev. D 98, 064041 (2018)] is extended in several significant ways. To begin with, the extra spatial dimension is assumed to be time dependent, while the redshift and shape functions, as well as the extra dimension, are functions of both r and l, the respective radial and extra coordinates;the last of these is therefore a function of r, l, and t. The main objective is to determine the conditions that allow the throat of the wormhole to be threaded with ordinary matter (by respecting the null energy condition) and that the same conditions lead to a violation of the null energy condition in the fifth dimension, which is therefore responsible for sustaining the wormhole. The dependence of the extra dimension on l and t is subject to additional conditions that are subsequently analyzed in this paper. Finally, the extra dimension may be extremely small or even curled up.

粒子穿越方势阱时的反射相位时间研究

To understand the physical meaning of phase time further more, we discuss the reflection phase time of quantum-particles passing though a potential well It is shown that the reflection phase time is equal to the transmission phase time in value and negative under certain conditions for a square potential well by analyzing While quantum-particles passing through the potential well, we think that this course can be described only with the velocity of energy of quantum mechanics whether or not they are reflected or transmitted eventually

轿车尾流移测试验研究

轿车的尾流结构与其空气阻力、升力与安全性有密切联系 ,为进一步研究轿车尾流结构及验证尾流场数值模拟结果的精确性提供依据 ,需通过试验得到较为全面地反映尾流结构的定量信息。为此 ,进行了红旗CA774轿车 1 10模型的七孔探针尾流移测试验 。

陀螺控制导线精度的正确评定

本文推证了陀螺控制导线精度评定的严密公式,并讨论了用误差椭圆来表示最弱点点位精度的方法。所有评定精度的公式均依据最小二乘矩阵平差原理得出,这些公式对正确进行误差预计很有意义。

THE NEW METHOD OF GENERATION OF BINARY TREES FROM ZER0(0) AND ONE(1) CODES

A binary tree can be represented by a code reflecting the traversal of the corresponding regular binary tree in given monotonic order. A different coding scheme based on the branches of a regular binary tree with n-nodes is proposed. It differs from the coding scheme generally used and makes no distinction between internal nodes and terminal nodes. A code of a regular binary tree with nnodes is formed by labeling the left branches by O’s and the right branches by l’s and then traversing these branches in pre-order. Root is always assumed to be on a left branch.

Web Security:Emerging Threats and Defense

Web applications have become a widely accepted method to support the internet for the past decade.Since they have been successfully installed in the business activities and there is a requirement of advanced functionalities,the configuration is growing and becoming more complicated.The growing demand and complexity also make these web applications a preferred target for intruders on the internet.Even with the support of security specialists,they remain highly problematic for the complexity of penetration and code reviewing methods.It requires considering different testing patterns in both codes reviewing and penetration testing.As a result,the number of hacked websites is increasing day by day.Most of these vulnerabilities also occur due to incorrect input validation and lack of result validation for lousy programming practices or coding errors.Vulnerability scanners for web applications can detect a few vulnerabilities in a dynamic approach.These are quite easy to use;however,these often miss out on some of the unique critical vulnerabilities in a different and static approach.Although these are time-consuming,they can find complex vulnerabilities and improve developer knowledge in coding and best practices.Many scanners choose both dynamic and static approaches,and the developers can select them based on their requirements and conditions.This research explores and provides details of SQL injection,operating system command injection,path traversal,and cross-site scripting vulnerabilities through dynamic and static approaches.It also examines various security measures in web applications and selected five tools based on their features for scanning PHP,and JAVA code focuses on SQL injection,cross-site scripting,Path Traversal,operating system command.Moreover,this research discusses the approach of a cyber-security tester or a security developer finding out vulnerabilities through dynamic and static approaches using manual and automated web vulnerability scanners.

伺服驱动在精确定位磁盘位置上的应用

"SIMODRIVE 611 Universal"是一种具有独立驱动控制器的轴控制模块,在"定位"方式下最多可被选择并执行64个快移程序段。文章介绍了SIMODRIVE 611U在自动打包机线中磁盘接近参考点原理及在吊装传递管捆过程中精确定位磁盘位置上的应用。

CASIO fx-4500P计算器在建筑工程测量中的应用(下)

9.1 计算导线转折角和 计算器全清零后,找到文件名“GZJH”,进行如下操作:

路径条件生成中的优化策略

为了提高利用符号执行生成测试数据的效率,提出了一种结合传统前向遍历和后向遍历的方法。通过对传统前向遍历和后向遍历方式的优缺点进行对比分析,设计了一个结合二者优点的算法。该算法将程序分块处理,整体采用前向遍历的思想,但在每一个块中是后向遍历代码的;它兼具前向遍历较早发现不可达路径的优点和后向遍历可以避免不相关变量赋值的优点,解决了传统前向遍历中的冗余问题。实验结果表明了该方法的可行性和有效性。

Soil Parameter Identification for Wheel-terrain Interaction Dynamics and Traversability Prediction

This paper presents a novel technique for identifying soil parameters for a wheeled vehicle traversing unknown terrain. The identified soil parameters are required for predicting vehicle drawbar pull and wheel drive torque, which in turn can be used for traversability prediction, traction control, and performance optimization of a wheeled vehicle on unknown terrain. The proposed technique is based on the Newton Raphson method. An approximated form of a wheel-soil interaction model based on Composite Simpson＇s Rule is employed for this purpose. The key soil parameters to be identified are internal friction angle, shear deformation modulus, and lumped pressure-sinkage coefficient. The fourth parameter, cohesion, is not too relevant to vehicle drawbar pull, and is assigned an average value during the identification process. Identified parameters are compared with known values, and shown to be in agreement. The identification method is relatively fast and robust. The identified soil parameters can effectively be used to predict drawbar pull and wheel drive torque with good accuracy. The use of identified soil parameters to design a traversability criterion for wheeled vehicles traversing unknown terrain is presented.

Influence of magnetically constricted arc traverse speed (MCATS) on tensile properties and microstructural characteristics of welded Inconel 718 alloy sheets

The magnetically constricted arc technique was implemented to mitigate the heat input related metallurgical problems in Gas Tungsten Arc Welding(GTAW)of Inconel 718 alloy particularly Nb segregation and subsequent laves phase evolution in fusion zone.This paper reports the direct effect of magnetically constricted arc traverse speed(MCATS)on bead profile,tensile properties and microstructural evolution of Inconel 718 alloy sheets joined by Gas Tungsten Constricted Arc Welding(GTCAW)process.The mechanism amenable for the microstructural modification and corresponding influence on the tensile properties of joints is investigated both in qualitative and quantitative manner related to the mechanics of arc constriction and pulsing.It is correlated to the solidification conditions during welding.The relationship between MCATS and Arc Constriction Current(ACC)was derived.Its interaction effect on the magnetic arc constriction and joint performance was analysed.Results showed that the joints fabricated using CATS of 70 mm/min exhibited superior tensile properties(98.39% of base metal strength with 31.50% elongation).It is attributed to the grain refinement in fusion zone microstructure leading to the evolution of finer,discrete laves phase in interdendritic areas.