Desired Dynamic Equation for Primary Frequency Modulation Control of Gas Turbines

Gas turbines play core roles in clean energy supply and the construction of comprehensive energy systems.The control performance of primary frequency modulation of gas turbines has a great impact on the frequency control of the power grid.However,there are some control difficulties in the primary frequency modulation control of gas turbines,such as the coupling effect of the fuel control loop and speed control loop,slow tracking speed,and so on.To relieve the abovementioned difficulties,a control strategy based on the desired dynamic equation proportional integral(DDE-PI)is proposed in this paper.Based on the parameter stability region,a parameter tuning procedure is summarized.Simulation is carried out to address the ease of use and simplicity of the proposed tuning method.Finally,DDE-PI is applied to the primary frequency modulation system of an MS6001B heavy-duty gas turbine.The simulation results indicate that the gas turbine with the proposed strategy can obtain the best control performance with a strong ability to deal with system uncertainties.The proposed method shows good engineering application potential.

A cellular automata traffic flow modeling of desired speed variability

The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maximal velocity. However, the behavior of the satisfaction rate as a function of the coefficient of variance is independent of the maximal velocity. This is in good agreement with empirical results obtained by Lipshtat [Phys. Rev. E 79 066110 （2009）]. Furthermore, our numerical result demonstrates that at low density the satisfaction rate takes higher values, whereas the coefficient of variance is close to zero. The coefficient of variance increases with increasing density, while the satisfaction rate decreases to zero. Moreover, we have also shown that, at low density the coefficient variance depends strongly on the probability of overtaking.

A new coupled map car-following model considering drivers' steady desired speed

Based on the pioneering work of Konishi et al., in consideration of the influence of drivers＇ steady desired speed ef/ect on the traffic flow, we develop a new coupled map car-following model in the real world. By use of the control theory, the stability condition of our model is derived. The validity of the present theoretical scheme is verified via numerical simulation, confirming the correctness of our theoretical analysis.

New Method for Confirming the Desired Safety Headway Distance and Desired Deceleration in ACC System

A new method of confirming the desired safety headway distance and desired deceleration is put forward according to the detected static or moving target and its simulation results in Matlab are also presented. The validity of the algorithm to calculate the reference speeds of both the ACC vehicle and the targeted car according to the vector quadrangle composed of the relative distance, the relative azimuth angle, the relative speeds of the vehicles has also been demonstrated through numerical example in Matlab. New laws to obtain the desired deceleration by estimating the braking force according to the vehicle analyses force equation are established too.

Fuzzy neural network control of underwater vehicles based on desired state programming

Due to the nonlinearity and uncertainty, the precise control of underwater vehicles in some intelligent operations hasn’t been solved very well yet. A novel method of control based on desired state programming was presented, which used the technique of fuzzy neural network. The structure of fuzzy neural network was constructed according to the moving characters and the back propagation algorithm was deduced. Simulation experiments were conducted on general detection remotely operated vehicle. The results show that there is a great improvement in response and precision over traditional control, and good robustness to the model’s uncertainty and external disturbance, which has theoretical and practical value.

Model of desired speed based on vehicle dynamic

The desired speed will help the drivers control their driver behavior that could directly influences the traffic safety. This paper presents a basic definition of a driver＇ s desired speed, and analyzes the effects of road geometer parameter, driver behavior and vehicle performance on the desired speed. By setting the familiar horizontal curve as the research environment, the generating process of the desired speed was described. Then, combined with the desired trajectory, the effect of driver＇ s identification of vehicle dynamic on the desired speed was highlighted. Based on the vehicle dynamic theory, a desired speed model that consisted of the desired trajectory, the driver＇s experience and vehicle parameter was established and numerically analyzed.

A desired landing points walking method enablinga planner quadruped robot to walk on rough terrain

It is necessary for legged robots to walk stably and smoothly on rough terrain.In this paper,a desired landing points(DLP) walking method based on preview control was proposed in which an off-line foot motion trace and an on-line modification of the trace were used to enable the robot to walk on rough terrain.The on-line modification was composed of speed modification,foot lifting-off height modification,step length modification,and identification and avoidance of unsuitable landing terrain.A planner quadruped robot simulator was used to apply the DLP walking method.The correctness of the method was proven by a series of simulations using the Adams and Simulink.

A New Method of Desired Gait Synthesis for Biped Walking Robot Based on Ground Reaction Force

A new method of desired gait synthesis for biped walking robot based on the ground reaction force was proposed. The relation between the ground reaction force and joint motion is derived using the D’Almbert principle. In view of dynamic walking with high stability, the ZMP(Zero Moment Point)stability criterion must be considered in the desired gait synthesis. After that, the joint trajectories of biped walking robot are decided by substituting the ground reaction force into the aforesaid relation based on the ZMP criterion. The trajectory of desired ZMP is determined by a fuzzy logic based upon the body posture of biped walking robot. The proposed scheme is simulated and experimented on a 10 degree of freedom biped walking robot. The results indicate that the proposed method is feasible.

Inverse Design of Phononic Crystal with Desired Transmission via a Gradient-Descent Approach

We propose a general approach based on the gradient descent method to study the inverse problem,making it possible to reversely engineer the microscopic configurations of materials that exhibit desired macroscopic properties.Particularly,we demonstrate its application by identifying the microscopic configurations within any given frequency range to achieve transparent phonon transport through one-dimensional harmonic lattices.Furthermore,we obtain the phonon transmission in terms of normal modes and find that the key to achieving phonon transparency or phonon blocking state lies in the ratio of the mode amplitudes at ends.

Efficient Method to Achieve Enhanced Thermal Dimensional Stability and Desired Dimensions of Hollow Polyester Fiber

This study has developed an efficient method to achieve excellent thermal dimensional stability and desired dimensions of hollow polyester fiber. Firstly,the influence of thermal treatment temperate( 140-180 ℃) on the degree of shrinkage of fiber was investigated. The influence was also analyzed with a 2nd heating to simulate the application situation. It was discovered that the heat treatment at a temperature which was above the application temperature( 2nd heating) would efficiently remove the internal stress in the fiber and improve the thermal dimensional stability.Secondly,the impact of heat treatment temperature on the fiber diameter and the degree of hollowness were studied. The results implied that with a fixed fiber length, higher treatment temperature led to thinner fiber and a lower degree of hollowness.Last but not least,key parameters that could further influence the fiber dimensions were investigated. The results suggested that the fiber diameters and the degree of hollowness could be further controlled by tuning the drawing speed,the spinning meter pump output and cooling status while the spinneret parameters were fixed.

基于Desirability函数法对米根霉发酵制备富马酸的多目标优化

以富马酸产量和生产速率为目标,通过正交实验考察了种龄、接种量、葡萄糖和尿素浓度对两者的影响,进一步利用基于响应曲面方法的Desirability函数确定了葡萄糖和尿素的最佳浓度。结果表明,最佳的种龄和接种量分别为36h和15%(v/v),葡萄糖和尿素的优化浓度为132.73和0.0586g/L,此时模型预测的富马酸产量和生产速率达到71.42g/L和0.804g/(l.h),Desirability的函数值高达0.966。该条件下在5L发酵罐水平上进行验证试验,经过88h的发酵最终生成富马酸66.5g/L,生产速率达到0.755g/(l.h),与未优化前相比,产量和生产速率分别提高了13.9%和15.8%,取得了理想的效果,实现了产量和生产速率的同时优化,为发酵法制备富马酸的工业化放大奠定了基础。

翻译文学的本土化策略探析——以The World’s Desire两个译本解读为例

目标语意识形态和诗学是影响翻译文学本土化的两个重要操控因素。林纾、周作人对英国冒险小说家哈格德The World’s Desire的翻译有着诸多差异,体现了意识形态和诗学在翻译本土化过程中所发挥的作用。这两个译本折射了翻译文学在中国的传播演变过程,也对中国文学翻译出口有一定的借鉴意义。

重庆市县域乡村三产融合与农户福祉的耦合协调关系研究——基于宜居宜业和美乡村视角

建设宜居宜业和美乡村是推进乡村全面振兴的阶段性任务。基于宜居宜业和美乡村视角,构建乡村三产融合与农户福祉的评价体系。通过分析二者的空间格局以及耦合协调关系,探讨了重庆市县域乡村的发展路径。研究结果表明:①重庆市县域乡村三产融合发展过程中受到农户福祉协同增进的作用,二者的耦合协调性较好,以适度协调和初级协调为主,整体上呈现出从过渡发展阶段向协调发展阶段转变的趋势。②分维度看,乡村三产融合行为的农业产业链延伸、乡村业态多元化与农业多功能性3个维度与农户福祉各维度间的耦合协调关系以农户福祉为刚性主导,而乡村三产融合成效的经济与社会效益两个维度与农户福祉各维度间的耦合协调关系以乡村三产融合为刚性主导;两者的高值区与低值区分布相对一致,高值区主要集中在渝西地区,低值区主要集中在渝东北片区偏东北边缘区域和渝东南片区偏东南边缘区域,二者之间呈现出显著的空间协同。③基于乡村三产融合与农户福祉的耦合协调关系,重庆市县域乡村可划分为3种耦合类型:乡村三产滞后型、同步型与农户福祉滞后型。据此,提出了建设宜业乡村、助推产业发展,宜居宜业乡村协同推进,建设宜居乡村、保障农户福祉3种路径,旨在促进乡村三产融合与农户福祉协调发展,让农民能够通过在农村从事农业及相关生产活动,享受到更加幸福的生活。

Brief Analysis on Naturalism and Realism in Desire Under the Elms

Desire Under the Elms was a drama written by Eugene O'Neill in 1924,which is called the first greatest drama in American history.Through analyzing the naturalistic features in this drama and the combination of naturalism and realism reflected in Desire Under the Elms,this article aims to help readers understand the lines and the relevant connotations better.

A Study on Bible Archetypes in Desire under the Elms

Desire under the Elms reveals a tragedy of spiritual and survival desire of human being. O'Neill creates many Bible archetypes in Desire under the Elms. The thesis analyzes and appreciates Desire under the Elms from aspect of Bible archetype to highlight the destructive power of improper desires in Desire under the Elms.

Storm:a Symbol of Desire—Analysis of The Storm by Kate Chopin

Changes in natural environment are usually the reflection of human inner world.The Storm was a short story written by Kate Chopin,an America female writer.In the story storm not only creates the setting for her immoral behavior,but also symbolizes the female protagonist,Calixta's desire for love.

智能超表面辅助的通感一体化性能优化

为了解决因障碍物等遮挡导致的覆盖空洞和探测精度下降问题,提出了一种基于栅格化的智能超表面辅助的通感一体化优化方法。首先,建模了最小化均方位置误差问题,将弱通感区域和RIS可能部署区域栅格化以降低计算难度,并采用粒子群优化算法和交替优化算法联合优化智能超表面期望反射角角度和部署位置。最后,引入探测需求因子,建模通感性能联合优化问题,并分析了探测需求因子对系统通感性能的影响。仿真结果显示:(1)相较于仅优化期望反射角,联合优化智能超表面的期望反射角和部署位置的方案,在平均信噪比仅有略微下降的情况下,可显著降低平均均方位置误差,平均均方位置误差降低10倍左右;(2)不同尺寸大小的智能超表面会对其最佳部署位置有影响;(3)联合优化智能超表面的期望反射角和部署位置提高了探测精度,最大化了通感整体性能。

Symbolic Image of Sky in Desire under the Elms

《榆树下的欲望》是美国剧作家尤金·奥尼尔的代表作之一。奥尼尔在《榆树下的欲望》中不仅以现实生活为蓝本,更揉入了许多寓意深刻的象征成分。本论文从象征主义的表现手法方面分析欣赏奥尼尔的著名悲剧《榆树下的欲望》,通过对作品中天空的象征意象的研究,使我们加深对奥尼尔戏剧的创作思想及其作品的主题意义的理解,同时更有利于寻找现代悲剧的创作根源。

A Study on Symbolic Images of land in Desire under the Elms

奥尼尔在《榆树下的欲望》中不仅以现实生活为蓝本，更揉入了许多寓意深刻的象征成分。本论文从象征主义的表现手法方面分析欣赏奥尼尔的著名悲剧《榆树下的欲望》，主要对作品中土地的象征意象进行了分析研究。

Optimization of CNC cutting parameters using design of experiment(DOE) and desirability function

In this study,2~5 （five factors at two-level factorial design） design of experiment was applied to investigate a set of optimal machining parameters to achieve a minimum surface roughness value for Abies nordmanniana.Wood specimens were prepared using different values of spindle speed,feed rate,depth of cut,tool radius,and cutting directions.Average surface roughness （R_z） values were applied using a stylus.The objectives were to：（1）obtain the effective variables of wood surface roughness;（2） analyze which of these factors had an impact on variability in the CNC machining process;（3） evaluate the optimal cutting values within the range of different cutting levels of machining parameters.The results indicate that the design of experiment（DOE） based on the desirability function approach determined the optimal machining parameters successfully,leading to minimum R_a compared to the observed value.Minimum surface roughness values of tangential and radial cutting directions were 3.58 and 3.21 μm,respectively.