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.

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.

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.

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.

On Laozi’s View of Desire

Laozi’s concept of desire has rich ideological connotations,not only referring to reducing personal desires.Laozi’s concept of desire is based on“desire”as human nature,acknowledging the legitimacy and necessity of desire and demand.The rational criticism of“having desire”formed by“no desire”is the value pursuit of Laozi’s concept of desire.From both personal physical and mental aspects and social order,“no desire”plays an important guiding role.Nature is the essence of Laozi’s concept of desire,and being in harmony with nature is the best state of desire.Laozi’s concept of desire reveals a deep spirit of love,and the“ethics of love”highlights Laozi’s strong sense of care for the“other”and ethical attitude towards responsibility.Laozi’s contemplation of desire contains a strong humanistic spirit,with the aim of promoting the healthy and sustainable development of life and society.

宜居宜业和美乡村建设水平评价与分类施策——以重庆市璧山区七塘镇为例

“建设宜居宜业和美乡村”是党的二十大对全面推进乡村振兴作出的战略部署.在阐释宜居宜业和美乡村科学内涵的基础上构建评价指标体系,以璧山区七塘镇为例开展实证研究,探讨建设宜居宜业和美乡村的实施路径.结果表明:(1)七塘镇宜居宜业和美乡村建设水平呈现“北高南低”的空间分布格局,总体建设位于中等水平,不同维度水平有差距.(2)分维度看,七塘镇生活维度水平最高,治理、人文和环境维度水平其次,产业维度水平最低.(3)分村域看,将军村、喜观村建设水平较高,四合村、阳岫村建设水平中等,盐店村、跃进村、建设村和三步梯村建设水平较低.(4)依据优势与短板,将七塘镇8个村划分为综合发展型、主导发展型、极化发展型和欠缺发展型4类,针对性地提出各类乡村建设宜居宜业和美乡村的实施路径,以期为推进宜居宜业和美乡村建设提供理论与实践指导.

青年“低欲望躺平”:全球图景、影响因素与引导策略

在全球图景下,以“躺平”为代表的青年低欲望现象已成为世界各国共同面临的难题。文章聚焦美国、英国、日本、韩国、巴西、印度、南非等国的青年低欲望现象,展现了世界各国的差异化表现,并剖析其产生原因。研究指出,全球青年低欲望现象的形成受到外源性因素和内源性因素的影响。其中,外源性因素包括经济下行时期青年就业困难,宗教信仰和社会文化中的男权色彩,以及社会舆论对“躺平”的负面评价;内源性因素包括与青年关系紧密的初级群体的基础素养,以及青年对教育体系和社会现状的不满,而且部分青年的低欲望表现已成为他们抵御社会异化的另类方式。研究提出,面对这一全球普遍存在的社会现象,我们既要承认青年低欲望现象的合理性,营造宽松和谐的社会环境,也要通过政府、媒体、家庭和个人的多方联动,加强青年社交情感发展和能力培养,帮助青年从“躺平”中站起来。

技术封建主义:文化霸权的新向度

技术封建主义是西方学界最近提出的一种理论话语,它力图对当下以互联网、大数据、云计算、人工智能等为表征的资本主义新状况进行阐释。学界对此的研究主要集中在经济和政治层面,而对于其文化影响则未有阐述。在新技术条件下,技术封建主义题旨已然溢出单纯的经济疆域和政治边界,广泛地渗透到当代社会生活的方方面面。在此语境中,技术封建主义的文化逻辑主要在知识垄断和大数据操控两个层面展开:一方面,通过窃取或掠夺而来的知识,文化霸权得到极大的巩固和加强;另一方面,通过大数据下的信息推送,根据大他者的欲望而结构起来的主体欲望得到了空前的关注和放大。由此,文化霸权以一种全新的样态给主体带来了前所未有的影响和规约。

生育政策、婚育状态与生活满意度:来自微观序数数据的证据

生活满意度一般是由李克特量表测算得到的序数数据构成,反映了个体对幸福感的主观评价,是基于理想和现实状况比较后的综合度量。现考虑在基数变量优势分析和指数测算的基础上调整修改,创新性地运用序数数据优势分析和序数数据指数测算方法刻画中国家庭追踪调查(CFPS)中个体婚育状态与生活满意度的分布特征,比较生育政策调整前后不同婚育状态下个体生活满意度在总体、性别间和孩次间的差异,分析其极化和不均衡状况。进一步,选取15~49岁育龄妇女作为生育主体,在关注年龄别育龄妇女生活满意度分布差异的同时,结合城乡、区域和受教育水平等育龄特征进行异质性分析,探究如何针对性地提升个体生活满意度以达到改善生育水平现状的目的。研究结果表明:生育政策调整后,总体满意度提升且极化和不均衡状况有所缓解;已婚二孩个体生活满意度最高,女性生活满意度高于男性;离异丧偶人群满意度差异较大,单身未婚女性和已婚男性满意度最为均衡,孩次由1孩变为2孩的满意度不均衡状况的缓解程度最大,年纪较轻的育龄人群缓解程度较大;育龄人群极化和不均衡状况与城乡发展、地区发展水平和受教育水平成反比。未来应继续加强社会福利体系建设,切实提高个体生活满意度进而提升社会整体生育意愿和生育水平。

红色旅游中原真性感知对出游渴望的影响——旅游涉入和收入预期的调节作用

基于后后现代主义视角,借鉴唤醒理论,以实验研究方法探究了原真性感知对情绪唤醒和旅游者出游渴望的影响。实验一表明创造性真实感知和现实性真实感知之间存在明显差异;实验二表明相对于现实性真实感知,创造性真实感知对旅游者情绪唤醒的影响更强;实验三和实验四分别验证了旅游涉入和收入预期在红色文化原真性感知和情绪唤醒之间的调节作用。研究为红色旅游发展提供了从后后现代主义视角观察原真性感知的思路,认为可以通过科技和艺术手段来增强红色文化原真性感知体验感。

绿色金融支持和美乡村建设的机制与路径研究

新时代新征程,建设宜居宜业和美乡村,对于满足国民对美好生活的新需求、提高乡村社会文明程度、推进农业农村现代化,进而全面建成社会主义现代化强国具有重要意义。这一目标的实现需要打造生态优质的“宜居”乡村、生产兴旺的“宜业”乡村、生活幸福的“和美”乡村。然而目前和美乡村建设面临着生态环境与经济发展相冲突及乡村建设资金短板尚未解决的现实挑战,为此本文提出要借助绿色金融之手来解决这些问题。绿色金融可以通过政府引导的积累机制与市场参与的投资机制,促进产业生态化与生态产业化实现生态补偿和修复及经营和权属交易。此外,借助绿色金融工具可以降低交易成本,从而实现乡村治理的激励相容,最终达成宜居宜业和美乡村建设的目标。

基于激光传感器的无人驾驶变换轨迹跟踪系统

针对常规无人驾驶轨迹跟踪过程依据一个给定的参考轨迹,存在跟踪角度及速度协同性较差、精度较低的问题,提出基于激光传感器的无人驾驶变换轨迹跟踪系统。设计包含激光传感器、电机控制、液晶显示、上位机通讯模块、键盘控制、微控制器的硬件结构,根据角速度及速度误差调整角速度协同控制器误差,通过神经元加权处理偏置数,优化双推角速度协同控制效果;引入滑模控制器,得到速度控制指令及角速度控制指令回角速度协同控制器,通过轨迹控制器和角速度协同控制器的设计,实现无人驾驶变换轨迹跟踪控制。实验结果表明,应用该系统后,角度轨迹跟踪结果更接近期望角度,直线状态和曲线状态下的轨迹跟踪误差均较小,最高为4 cm,轨迹跟踪精度高、定位准,整体应用效果更佳。

生育价值观对当代大学生生育意愿的代际影响

文章以某高校大学生及其父母为研究对象,探讨生育价值观对当代大学生生育意愿的影响以及父母的生育价值观对当代大学生生育意愿的代际影响。结果发现:(1)父母的平均生育意愿为1.50个孩子,实际生育数为2.29个孩子,当代大学生的生育意愿为1.04个孩子。(2)当代大学生的生育意愿与其父亲、母亲的生育意愿间的相关均不显著;父亲与母亲生育意愿间的相关也不显著;母亲的生育意愿与实际生育行为间的相关不显著;但父亲的生育意愿与实际生育行为间呈显著的正相关。(3)VOC+对当代大学生的生育意愿有正向预测作用;VOC-对当代大学生的生育意愿有负向预测作用。(4)当代大学生的生育意愿与父亲的生育价值观之间的相关不显著,但与母亲的生育价值观间的相关显著;父亲的VOC+对当代大学生的生育意愿没有正向预测作用,VOC-也没有负向预测作用;母亲的VOC+对当代大学生的生育意愿有正向预测作用,但VOC-却没有负向预测作用。研究结果有助于全面了解当代大学生的生育意愿及其影响因素,对提升当代大学生的生育意愿有启示意义。

新发展阶段制造业“合意”比重区间探讨

2006—2018年,我国制造业增加值占国民生产总值比重下降了9.3个百分点,而人均GDP并未达到能够主要依靠服务业实现经济稳定增长的水平,制造业比重的过早、过快下降引发了广泛的担忧。研究认为,在满足工业化一般规律、符合当前技术革命时代特征和中国特殊国情的基础上,中国制造业比重存在一个“合意”区间,这一区间低于发达国家同等发展阶段的平均水平、高于中等发达国家当前平均水平,略高于日德韩等制造强国当前水平、显著高于落入中等收入陷阱国家制造业比重的峰值,同时能够保障在2035年实现人均GDP达到中等发达国家水平战略目标的实现,即在2025年为26.8%~27.3%、2030年为26.3%~26.6%、2035年为25.6%~26.0%。技术进步、国内市场增长、要素配置优化、产业政策改进、区域布局调整能够为我国制造业在产值规模增长放缓的情况下,增加值比重稳定在“合意”区间提供支撑,而要释放制造业发展新动能,则需要着力培育把握新工业革命机遇的能力、发展动力稳定转化的能力和应对外部挑战的能力。