Improving the Transmission Security of Vein Images Using a Bezier Curve and Long Short-Term Memory

The act of transmitting photos via the Internet has become a routine and significant activity.Enhancing the security measures to safeguard these images from counterfeiting and modifications is a critical domain that can still be further enhanced.This study presents a system that employs a range of approaches and algorithms to ensure the security of transmitted venous images.The main goal of this work is to create a very effective system for compressing individual biometrics in order to improve the overall accuracy and security of digital photographs by means of image compression.This paper introduces a content-based image authentication mechanism that is suitable for usage across an untrusted network and resistant to data loss during transmission.By employing scale attributes and a key-dependent parametric Long Short-Term Memory(LSTM),it is feasible to improve the resilience of digital signatures against image deterioration and strengthen their security against malicious actions.Furthermore,the successful implementation of transmitting biometric data in a compressed format over a wireless network has been accomplished.For applications involving the transmission and sharing of images across a network.The suggested technique utilizes the scalability of a structural digital signature to attain a satisfactory equilibrium between security and picture transfer.An effective adaptive compression strategy was created to lengthen the overall lifetime of the network by sharing the processing of responsibilities.This scheme ensures a large reduction in computational and energy requirements while minimizing image quality loss.This approach employs multi-scale characteristics to improve the resistance of signatures against image deterioration.The proposed system attained a Gaussian noise value of 98%and a rotation accuracy surpassing 99%.

Obstacle Avoidance and Multitarget Tracking of a Super Redundant Modular Manipulator Based on Bezier Curve and Particle Swarm Optimization

A super redundant serpentine manipulator has slender structure and multiple degrees of freedom.It can travel through narrow spaces and move in complex spaces.This manipulator is composed of many modules that can form different lengths of robot arms for different application sites.The increase in degrees of freedom causes the inverse kinematics of redundant manipulator to be typical and immensely increases the calculation load in the joint space.This paper presents an integrated optimization method to solve the path planning for obstacle avoidance and discrete trajectory tracking of a super redundant manipulator.In this integrated optimization,path planning is established on a Bezier curve,and particle swarm optimization is adopted to adjust the control points of the Bezier curve with the kinematic constraints of manipulator.A feasible obstacle avoidance path is obtained along with a discrete trajectory tracking by using a follow-the-leader strategy.The relative distance between each two discrete path points is limited to reduce the fitting error of the connecting rigid links to the smooth curve.Simulation results show that this integrated optimization method can rapidly search for the appropriate trajectory to guide the manipulator in obtaining the target while achieving obstacle avoidance and meeting joint constraints.The proposed algorithm is suitable for 3D space obstacle avoidance and multitarget path tracking.

Graphics Evolutionary Computations in Higher Order Parametric Bezier Curves

This work demonstrates in practical terms the evolutionary concepts and computational applications of Parametric Curves.Specific cases were drawn from higher order parametric Bezier curves of degrees 2 and above.Bezier curves find real life applications in diverse areas of Engineering and Computer Science,such as computer graphics,robotics,animations,virtual reality,among others.Some of the evolutionary issues explored in this work are in the areas of parametric equations derivations,proof of related theorems,first and second order calculus related computations,among others.A Practical case is demonstrated using a graphical design,physical hand sketching,and programmatic implementation of two opposite-faced handless cups,all evolved using quadratic Bezier curves.The actual drawing was realized using web graphics canvas programming based on HTML 5 and JavaScript.This work will no doubt find relevance in computational researches in the areas of graphics,web programming,automated theorem proofs,robotic motions,among others.

A transition method based on Bezier curve for trajectory planning in cartesian space

In order to smooth the trajectory of a robot and reduce dwell time,a transition curve is introduced between two adjacent curves in three-dimensional space.G2 continuity is guaranteed to transit smoothly.To minimize the amount of calculation,cubic and quartic Bezier curves are both analyzed.Furthermore,the contour curve is characterized by a transition parameter which defines the distance to the corner of the deviation.How to define the transition points for different curves is presented.A general move command interface is defined for receiving the curve limitations and transition parameters.Then,how to calculate the control points of the cubic and quartic Bezier curves is analyzed and given.Different situations are discussed separately,including transition between two lines,transition between a line and a circle,and transition between two circles.Finally,the experiments are carried out on a six degree of freedom(DOF) industrial robot to validate the proposed method.Results of single transition and multiple transitions are presented.The trajectories in the joint space are also analyzed.The results indicate that the method achieves G2 continuity within the transition constraint and has good efficiency and adaptability.

A path planning algorithm based on Bezier curves for underwater vehicles

An on-line path planning algorithm based on Bezier curves is presented for underwater vehicles. Aiming at the special requirements of underwater vehicles and 3D enviromnent, the algorithm consists of two steps ： the generation of spatial path and the processing of some constraints. A path for underwater vehicles is planned, which satisfies the velocity constraint and the centripetal acceleration constraint of underwater vehicles. The proposed path planning method can be used for the vehicle＇ s locomotion and navigation control.

Shape Control and Modification of Rational Bezier Curve and Surface

A Bezier interpolation approach is proposed which uses local generation of endpoint slopes and forces the curve and the surface to pass through an arbitrarily specified point to control and modify the shape of curve and surface, making the result satisfactory.

Development of Cubic Bezier Curve and Curve-Plane Intersection Method for Parametric Submarine Hull Form Design to Optimize Hull Resistance Using CFD

Optimization analysis and computational fluid dynamics （CFDs） have been applied simultaneously, in which a parametric model plays an important role in finding the optimal solution. However, it is difficult to create a parametric model for a complex shape with irregular curves, such as a submarine hull form. In this study, the cubic Bezier curve and curve-plane intersection method are used to generate a solid model of a parametric submarine hull form taking three input parameters into account： nose radius, tail radius, and length-height hull ratio （L/H）. Application program interface （API） scripting is also used to write code in the ANSYS DesignModeler. The results show that the submarine shape can be generated with some variation of the input parameters. An example is given that shows how the proposed method can be applied successfully to a hull resistance optimization case. The parametric design of the middle submarine type was chosen to be modified. First, the original submarine model was analyzed, in advance, using CFD. Then, using the response surface graph, some candidate optimal designs with a minimum hull resistance coefficient were obtained. Further, the optimization method in goal-driven optimization （GDO） was implemented to find the submarine hull form with the minimum hull resistance coefficient （Ct）. The minimum C, was obtained. The calculated difference in （7, values between the initial submarine and the optimum submarine is around 0.26%, with the C, of the initial submarine and the optimum submarine being 0.001 508 26 and 0.001 504 29, respectively. The results show that the optimum submarine hull form shows a higher nose radius （rn） and higher L/H than those of the initial submarine shape, while the radius of the tail （r1） is smaller than that of the initial shape.

基于Bezier曲线的气膜冷却孔出口孔形优化

提出一种基于Bezier曲线的气膜冷却孔出口参数化构型方法,通过调整Bezier曲线的控制点,改变气膜冷却孔的出口形状。采用拉丁超立方抽样(LHS)和数值模拟的方法,获得大量不同气膜冷却孔出口形状下的气膜冷却效果,结合径向基函数神经网络(RBF-NN)所构建的预测模型和遗传算法(GA)进行气膜冷却孔出口形状优化。结果表明:优化后的气膜冷却孔可以有效抑制肾形涡对(CVP)的强度与大小,减小冷却气流与热主流的掺混损失;优化后的气膜冷却孔具有扩张的冷却通道,降低了冷却气流出口法向上的动量,有效抑制了冷却气流对于热主流的穿透,提升了气膜冷却效率;在吹风比M=0.91的情况下,最优孔形的气膜冷却效率较圆孔和扇形孔分别提升了40.48%和17.82%。

一种带参数的二次Bezier曲线的连续条件

针对计算机辅助几何设计中曲线的光滑拼接问题,研究了一种带参数的二次Bezier曲线的连续条件.利用曲线性质给出了两条带参数的二次Bezier曲线在连接点处实现光滑拼接的充要条件,并得到了该曲线间G^(l)、G^(2)、C^(l)、C^(2)光滑拼接的定理。利用实例计算表明,该连续条件易于实现复杂曲线的构造,可为参数曲线的设计提供良好参考。

Bezier型曲线内能极小化的通用方法及其应用

虽然Bezier型曲线中包含的形状参数可提高其形状表现能力,但如何通过确定形状参数的最佳取值对Bezier型曲线的形状进行优化也值得关注.该文提出了通过对三种常见内能极小化来确定Bezier型曲线中所含形状参数最优值的通用方法,该方法包括极小化一种内能,同步极小化其中两种内能以及同步极小化三种内能等情形.最后利用一种被称为三次替代曲线的Bezier型曲线对文中所提出的方法进行了检验,结果表明这些方法是可行的.

VERIFYING THE IMPLICITIZATION FOR MULAE FORDEGREE n RATIONAL BEZIER CURVES

This is a continuation of short communication([1]). In [1] a verification of the implicitization equation for degree two rational Bezier curves is presented which does not require the use of resultants. This paper presents these verifications in the general cases, i.e., for degree n rational Bezier curves. Thus some interesting interplay between the structure of the n x n implicitization matrix and the de Casteljau algorithm is revealed.

基于Bezier曲线优化的茶园拖拉机避障稳定控制方法

针对茶园拖拉机(tractor in tea plantation,TTP)在作业时进行避障转弯极易发生侧翻、倾覆等安全问题,提出一种基于Bezier曲线优化的避障稳定路径控制方法.首先,从作业场景和运行稳定性两个方面进行运动学分析,系统分析了TTP安全作业特点;然后,针对TTP设计了一种避障路径规划系统方案及Bezier曲线路径优化控制方法,该方法拟合出的路径具有路径光滑、曲率连续、初末位置曲率相同等优点;最后,在CarSim仿真平台搭建TTP模型和坡道避障作业的环境模型,验证并分析横摆角速度、质心侧偏角两项重要的操稳性参数.结果表明:TTP在Bezier曲线拟合的避障路径控制方法下当运行速度小于转向极限速度时,运行稳定性良好,当转向速度超过极限速度的65.1%,其横摆角速度和质心侧偏角的超调量变化率分别达到了50.3%和78.6%;同时在该避障控制方法下,随着坡度的增加,即使速度保证在极限速度以下,TTP稳定性也会进一步恶化;在极限坡度角范围内,坡度角增大10°,其横摆角速度和质心侧偏角的超调量变化率平均达到了32.8%和14.5%.

Bezier曲线与A-Star算法融合的火星探测器路径规划

使用移动探测器探索火星表面是各大航天国家探索火星的主流方式。为了得到探测器的安全路径,提出一种基于改进A^(*)算法的火星探测器路径规划算法。通过改进路径信息算法中的权重因子,优化传统算法的目标函数,可省略大量无价值的搜索路径,缩短搜索的时间,提高搜索效率。相比于传统的路径规划该算法能缩短53.94%的时间;引入拐角优化算法,在路径长度基本一致的情况下,减少了全局路径中拐弯的次数;满足探测器高效稳定的运行需求,拐角优化后,转弯次数相能减少16.77%。通过四阶贝塞尔曲线对路径进行平滑处理,有效避免出现拐角尖峰,确保探测器在火星表面的平稳行进。

带形状参数的五次Bezier曲线的光滑拼接

针对复杂曲线的造型研究了带形状参数的五次Bezier曲线的光滑拼接问题。利用基函数性质和曲线性质,得到了曲线间的G^(1)、G^(2)、C^(1)、C^(2)光滑拼接定理。通过计算实例验证了曲线间拼接条件的有效性。

基于改进A*算法的应急救援无人机路径规划

针对救援无人机传统路径规划算法存在搜索扩展节点数多、搜索路径时间长、规划轨迹不平滑的缺点,提出了一种改进A*算法的应急救援无人机路径规划方法。采用对角线距离作为启发函数并进行指数加权,通过双向搜索策略进行搜索优化,对生成的路径点使用贝塞尔曲线进行曲线拟合。实验中设计了多种非结构化地图,对Dijkstra算法、传统A*算法和改进A*算法在搜索扩展节点数、规划路径长度和搜索路径时间三方面进行对比。实验结果表明,设计的多种地图中改进A*算法在搜索扩展节点数较Dijkstra算法和传统A*算法分别至少降低了59.82%、39.40%,在搜索路径时间分别至少降低了57.38%、33.46%,规划后的路径经过贝塞尔曲线优化后满足无人机的实际飞行要求,可以实现高效率无人机应急救援。

基于混合神经网络的多维视觉传感信号模式分类

传感器采集的数字信号分类精度差,导致关键信息的丢失。为了提高传感数据的可靠性和有效性,提出基于混合神经网络的多维视觉传感信号模式分类方法。结合卷积神经网络(CNN)、循环神经网络(RNN)构建混合神经网络,以更有效地表示多维视觉数据中的特征;其中,卷积神经网络负责对多维的空间信号进行去噪处理并提取特征;循环神经网络负责对时域和频域信号进行特征提取;混合神经网络通过联合训练CNN和RNN各自的参数,以调整其权重,并且结合两者从不同层级提取的特征来实现多维视觉传感信号模式的分类。仿真结果表明,使用所提方法进行分类时,信号光滑度保持在0.9以上,传感信号分类结果与实际结果拟合度较高,有效实现多维视觉传感信号模式分类。

Degree elevation from Bzier curve to C-Bzier curve with corner cutting form

The existing results of curve degree elevation mainly focus on the degree of algebraic polynomials. The paper considers the elevation of degree of the trigonometric polynomial, from a Bezier curve on the algebraic polynomial space, to a C-Bezier curve on the algebraic and trigonometric polynomial space. The matrix of degree elevation is obtained by an operator presentation and a derivation pyramid. It possesses not a recursive presentation but a direct expression. The degree elevation process can also be represented as a corner cutting form.

基于可视图与改进遗传算法的机器人平滑路径规划

针对传统遗传算法在路径规划中存在收敛速度慢、易早熟和路径质量差等缺点,提出一种基于可视图与改进遗传算法的路径规划算法。首先,利用可视图法压缩地图信息,减少搜索节点;然后,对路径个体采用浮点数编码,引入模拟二进制交叉(simulated binary crossover,SBX)算子和多项式变异算子,并采用精英保留策略和轮盘赌相结合的选择算子以防止优质个体丢失;之后,将贝塞尔(Bezier)算子引入遗传算法,改善路径的平滑性;最后,分段优化贝塞尔控制节点,防止优化路径与障碍物碰撞。在仿真地图中进行测试,实验结果表明,所提算法相比于其他算法可以规划出一条更平滑、更短的路径。将算法应用在康复助行机器人中进行测试,实验结果表明,所提算法能有效解决机器人的全局路径规划问题,提升全局路径规划的效率。

基于混合A^(*)搜索和贝塞尔曲线的船舶进港和靠泊路径规划算法

[目的]针对欠驱动无人艇自动进港和靠泊问题,提出一种基于混合A^(*)搜索和贝塞尔曲线的路径规划算法。[方法]该方法通过混合A^(*)搜索在非结构化环境下快速搜索出一条满足无人艇非完整性约束且无碰撞风险的轨迹。在此基础上,基于广义沃罗诺伊图提出曲线优化算法,使得搜索算法得到的轨迹更加平滑且远离环境障碍物,从而引导无人艇在受限水域完成进港任务。同时,针对“最后一公里”靠泊问题,引入四阶贝塞尔曲线,用于生成靠泊路径从而引导船体平稳且精准入泊。[结果]仿真和外场试验结果表明,无人艇能够实现自主避障且精准驶入泊位,靠泊精度指标均小于1.0。[结论]所提路径规划算法能确保欠驱动无人艇实现进港和靠泊任务,可为智能船舶的进一步发展提供思路。