Synthetic analysis of meteorological elements for the sea fogs occurred in northwest the Yellow Sea under low pressure control and comparison with sea fogs occurred under high pressure control in summer

Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation situation,divergence and vertical velocity field,and the vertical profile of temperature and humidity are synthesized and analyzed.The basic characteristics of the circulation and physical field of sea fog under low pressure control(L type sea fog)are obtained,and the results are compared with the sea fog under the control of high pressure(H type sea fog):a)L type sea fogs potential height anomaly disturbance is mainly manifested in the low layer,and its average value is-65.66 gpm,gradually weakening upward;b)L type sea fogs inversion structure is weaker than H type sea fogs when it occurs,the fog layer is thicker and the high relative humidity level is high over the fog layer,while the H type sea fogs fog layer has a relatively obvious dry layer;c)L sea fog has three layers of structure at the vertical direction.The first layer 1000-950 hPa is convergence accompanied by weak rise and subsidence,the second layer 950-850 hPa is divergence accompanied by weak subsidence,and the third layer 850 to 500hPa is gradually strengthened.While there are two layer structures of the H type sea fog.1000 hPa is divergence accompanied by weak rising and sinking movement,950-500 hPa is a uniform subsidence movement.d)Probability density statistical analysis further quantified the vertical movement of L and H type sea fog and the distribution of relative humidity in each layer.These conclusions provide an important reference for forecasting the sea fog in the northwest of the Yellow Sea under the condition of low pressure circulation in summer.

The Application of Synthetic Fuzzy Assessing Method in Measurement and Control System of Plating Solution Evaporator

The synthetic fuzzy assessing method is usually applied to sensory evaluation. The method has simple and reliable virtue, and it is consistent with objective evaluation results. Using this method, system status of plating solution evaporator is evaluated, and the result is applied to compensate a fuzzy controller. Experimental results have shown the correctness and the validity of the proposed approach.

Does city lockdown prevent the spread of COVID-19?New evidence from the synthetic control method

Background:At 10 a.m.on January 23,2020 Wuhan,China imposed a 76-day travel lockdown on its 11 million residents in order to stop the spread of COVID-19.This lockdown represented the largest quarantine in the history of public health and provides us with an opportunity to critically examine the relationship between a city lockdown on human mobility and controlling the spread of a viral epidemic,in this case COVID-19.This study aims to assess the causal impact of the Wuhan lockdown on population movement and the increase of newly confirmed COVID-19 cases.Methods:Based on the daily panel data from 279 Chinese cities,our research is the first to apply the synthetic control approach to empirically analyze the causal relationship between the Wuhan lockdown of its population mobility and the progression of newly confirmed COVID-19 cases.By using a weighted average of available control cities to reproduce the counterfactual outcome trajectory that the treated city would have experienced in the absence of the lockdown,the synthetic control approach overcomes the sample selection bias and policy endogeneity problems that can arise from previous empirical methods in selecting control units.Results:In our example,the lockdown of Wuhan reduced mobility inflow by approximately 60%and outflow by about 50%.A significant reduction of new cases was observed within four days of the lockdown.The increase in new cases declined by around 50%during this period.However,the suppression effect became less discernible after this initial period of time.A 2.25-fold surge was found for the increase in new cases on the fifth day following the lockdown,after which it died down rapidly.Conclusions:Our study provided urgently needed and reliable causal evidence that city lockdown can be an effective short-term tool in containing and delaying the spread of a viral epidemic.Further,the city lockdown strategy can buy time during which countries can mobilize an effective response in order to better prepare.Therefore,in spite of initial widespread skepticism,lockdowns are likely to be added to the response toolkit used for any future pandemic outbreak.

Global Inverse Optimal Tracking Control of Underactuated Omni-directional Intelligent Navigators （ODINs）

This paper presents a design of optimal controllers with respect to a meaningful cost function to force an underactuated omni-directional intelligent navigator （ODIN） under unknown constant environmental loads to track a reference trajectory in two-dimensional space. Motivated by the vehicle＇s steering practice, the yaw angle regarded as a virtual control plus the surge thrust force are used to force the position of the vehicle to globally track its reference trajectory. The control design is based on several recent results developed for inverse optimal control and stability analysis of nonlinear systems, a new design of bounded disturbance observers, and backstepping and Lyapunov＇s direct methods. Both state- and output-feedback control designs are addressed. Simulations are included to illustrate the effectiveness of the proposed results.

Study on the Impact of Collective Commercial Construction Land Entering the Market on Rural Residents’Income:Taking Deqing County,Zhejiang Province as an Example

The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalization.Since the production of the first batch of pilot projects in 2015,33 county-level cities have participated in the pilot policy by 2023.Deqing County,Zhejiang Province,as the first area to participate in the pilot project,aims to achieve more fruitful results.This paper first examines how promoting farmers’income through the market entry of agricultural land can be achieved,then uses the synthetic control method to quantitatively study the impact of collective operational construction land on farmers’income using panel data from 2011 to 2019,and finally proposes relevant suggestions from the perspective of system reform.

Method of Inequalities-based Multiobjective Genetic Algorithm for Optimizing a Cart-double-pendulum System

This article presents a multiobjective approach to the design of the controller for the swing-up and handstand control of a general cart-double-pendulum system （CDPS）. The designed controller, which is based on the human-simulated intelligent control （HSIC） method, builds up different control modes to monitor and control the CDPS during four kinetic phases consisting of an initial oscillation phase, a swing-up phase, a posture adjustment phase, and a balance control phase. For the approach, the original method of inequalities-based （MoI） multiobjective genetic algorithm （MMGA） is extended and applied to the case study which uses a set of performance indices that includes the cart displacement over the rail boundary, the number of swings, the settling time, the overshoot of the total energy, and the control effort. The simulation results show good responses of the CDPS with the controllers obtained by the proposed approach.

Direct adaptive control for lane keeping in intelligent vehicle systems

In this paper, with parametric uncertainties such as the mass of vehicle, the inertia of vehicle about vertical axis, and the tire cornering stiffness, we deal with the vehicle lateral control problem in intelligent vehicle systems. Based on the dynamical model of vehicle, by applying Lyapunov function method, the control problem for lane keeping in the presence of parametric uncertainty is studied, the direct adaptive algorithm to compensate for parametric variations is proposed and the terminal sliding mode variable structure control laws are designed with look-ahead references systems. The stability of the system is investigated from the zero dynamics analysis. Simulation results show that convergence rates of the lateral displacement error, yaw angle error and slid angle are fast.

Nonlinear system compound inverse control method

A compound neural network is utilized to identify the dynamic nonlinear system. This network is composed of two parts： one is a linear neural network, and the other is a recurrent neural network. Based on the inverse theory a compound inverse control method is proposed. The controller has also two parts： a linear controller and a nonlinear neural network controller. The stability condition of the closed-loop neural network-based compound inverse control system is demonstrated .based on the Lyapunov theory. Simulation studies have shown that this scheme is simple and has good control accuracy and robustness.

Key techniques of automatic gauge control and profile control for aluminium strip and foil

Such characteristics of aluminium strip and foil as soft and thin gauge make tension control one of the key techniques for automation gauge control(AGC). To avoid the disadvantage of traditional mathematical control method which is unfitful for nonlinear hysteresis, the technique for tension AGC fuzzy control was developed and thickness deviation more than 3% of product thickness was achieved consequently in 1 350 mm cold rolling mill of aluminium strip and foil. Additionally, because the gauge of aluminium strip and foil is thin, stage-cooling roll method becomes a key technique for profile control. So stage-cooling roll intelligent control method is developed and pre-coated aluminum foil with good profile less than 10 I (the relative differences in elongation of 0.01%) is produced using the profile control system in 1 400 mm cold rolling mill of aluminium strip and foil.

Does Environmental Regulation Increase Employment? Based on the SCM and RCM Methods

Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.

The effect of hosting international mega-events on urban haze pollution in China:Based on a quasi-natural experiment

With the rapid economic and social development of China,more and more Chinese cities are hosting important international events.However,the long-term effects of hosting international events on urban haze pollution are rarely discussed in existing literature.Based on the quasi-natural experiment of China hosting the G20 Hangzhou Summit in 2016,this paper applies the synthetic control method (SCM) for the first time to evaluate the impact of the G20 Hangzhou Summit on urban haze pollution in China.Compared with the traditional method,SCM measures the long-term impact of hosting the G20 Summit on haze pollution more scientifically.The results show that hosting the G20 Summit did improve the haze pollution in Hangzhou.The effectiveness and robustness of the above conclusions are objectively confirmed by multi-dimensional tests such as placebo test,permutation test,iterative test and difference-in-differences model.Further mechanism analysis shows that foreign direct investment and technological innovation are important channels for the G20 Summit to curb haze pollution in Hangzhou.At the same time,this paper employs a series of methods to systematically evaluate the impact of the G20 Hangzhou Summit on haze pollution in both time and space dimensions.This paper provides a credible basis and empirical support for the impact of international mega-events on air pollution in China.

Interaction and the Genesis of Experience: A Phenomenological Contribution for Meaningful Embodied Artificial Intelligence

In this article I will address the issue of the meaning of Embodied Artificial Intelligence(EAI)as it is configured today.My starting point is the refined interactive perspective on the semantics of EAI,as was recently suggested by Froese and colleagues.This perspective rests on the assumption that the concept of human bodily subjectivity must be extended to include meaning-making processes,which are enabled by advanced AI systems that may be incorporated in the human biological body.After having clarified the technical background,I will introduce the genetic component of the phenomenological method as a suitable tool to face the aforementioned issue.Towards this end,I will place the genetic method in the context of the so-called New Human-Machine Interaction(New HMI).I will further outline a genetic phenomenology of visual embodiment,suggesting a futuristic application based on the thesis of the“technological supplementation of phenomenological methodology”through the synthetic method.The case at stake is that of patients with a severe clinical picture characterised by the loss of corneal function,who in the near future could be treated with synthetic corneal prosthetic implants produced by a 3D bio-printing process by using an advanced EAI technique.I will conclude this article with a brief review of the main problems that still remain open.

Design of BLDCM Driving and Control System for Motorized Treadmill

To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor （BLDCM） driving and control system for motorized treadmill is developed. High integration and reliability of this system are ensured under the condition that intelligent power module （IPM） is used and the protection module is included. Periodic current control method is applied to reduce the average current flowing through the armature winding of the motor when the treadmill is required to start with low speed while large load is added. Piecewise proportion-integration-differentiation （PID） control algorithm is applied to solve the problem of speed fluctuation when impulse load is added. The motorized treadmill of a new generation with the driving and control system has the advantages of high reliability, good speed stability, wide timing scope, low cost, and long life-span. And it is very promising for practical applications.

自由贸易试验区经济效应与影响路径分析——以中国(四川)自贸试验区为例

中国(四川)自由贸易试验区作为首批内陆型自贸区之一,自2017年4月揭牌设立以来在完成改革试验任务、制度创新成果推广、开放引领作用、营商环境优化等方面均取得显著成效,并极大地促进了四川地区经济增长。采用合成控制法评估设立四川自贸区的经济效应,并从消费、外商直接投资和进出口贸易三个渠道分析自贸区影响地区经济增长的路径,在此基础上再进行双重差分估计和变换处理组单元与控制组单元的安慰剂检验。实证结果表明,四川自贸区设立对当地经济增长具有显著的正向推动作用,且影响路径是外商直接投资和进出口贸易,相比而言通过提升消费来促进四川地区经济增长的影响统计意义上并不显著。

房产税改革的合成控制法分析——基于沪渝视角

利用2006—2021年35个大中城市的面板数据,以2011年沪渝房产税改革试点作为自然实验,从居民收入分配和政府公共服务两个维度,运用合成控制法评估房产税改革的影响效果。结果表明:(1)总体上,房产税对社会公平存在异质性影响,重庆税改方案的公平性较强,上海相对较弱;(2)“重庆模式”有助于缩小居民收入分配差距,“上海模式”则相反,但两种模式都显著提升了政府公共服务均等化水平。对此,可采取如下措施:优化税改方案,扩推房产税改革;规范公共服务,稳定财政收入来源;缩小收入分配差距,注重城乡统筹发展;注重“差异”与“适用”,突出地方税特征等。

中国土地制度改革促进农业生产绩效吗?——基于“三权分置”制度的准自然实验

加快完善中国土地制度是优化农地要素配置、促进农业新质生产力发展的内在要求。首先以世界65个主要国家作为样本池数据,采用合成控制法分析了“三权分置”改革的增产和增收效应。结果显示“三权分置”制度对亩均谷物产量和农业增加值的净作用为5.4%和12.1%,显著提高农业增产和增收能力。进一步分析发现,“三权分置”制度的增产增收作用比农地私有制国家情形高5.9%和7.7%,比农地公有制国家情形高8.4%和32.3%,体现出“三权分置”制度的优越性。并将我国的省份视作实验组样本,采用DID的方法验证了结果的稳健性。最后,建议对农地市场进行适度规制,消除各种可能导致土地经营权市场失灵的因素,充分保障农地市场化配置的有效性,更好地发挥农地制度优越性。

Robust Attitude Control for Reusable Launch Vehicles Based on Fractional Calculus and Pigeon-inspired Optimization

In this paper, a robust attitude control system based on fractional order sliding mode control and dynamic inversion approach is presented for the reusable launch vehicle RLV during the reentry phase. By introducing the fractional order sliding surface to replace the integer order one, we design robust outer loop controller to compensate the error introduced by inner loop controller designed by dynamic inversion approach. To take the uncertainties of aerodynamic parameters into account, stochastic robustness design approach based on the Monte Carlo simulation and Pigeon-inspired optimization is established to increase the robustness of the controller. Some simulation results are given out which indicate the reliability and effectiveness of the attitude control system. © 2014 Chinese Association of Automation.

Identification of Nonlinear Dynamic Systems Using Diagonal Recurrent Neural Networks

In order to apply a new dynamic neural network- Diagonal Recurrent Neural NetWork (DRNN) to the system identificationof nonlinear dynamic Systems and construct more accurate system models, the structure and learning method (DBP algorithm) of theDRNN are Present6d. Nonlinear system characteriStics can be identified by presenting a set of input / output patterns tO the DRNN andadjusting its weights with the DBP algorithm. Experimental results show that the DRNN has good performances in the identification ofnonlinear dynamic systems in comparison with BP networks.

Spatial emission reduction effects of China’s carbon emissions trading:quasi-natural experiments and policy spillovers

Insufficient assessment of emission reduction effects still exists in the carbon emission rights trading system,a major environmental regulation measure in China.Based on the data from the carbon trading pilot covering the years from 2007 to 2017,this study combined the synthetic control method with dynamic spatial Durbin model to comprehensively evaluate the spatial emission reduction effects of carbon trading policies.The results showed that:①The carbon trading policies promoted carbon emission reductions in the pilot regions,among which Tianjin and Hubei responded significantly,and also helped to suppress carbon emissions in the neighboring areas.②Long-term emission reduction effect from carbon emissions trading became gradually significant,while the indirect emission reduction effect was relatively weaker.③In term of reducing carbon emissions,the economic development channel played a key role,but it had a threat to the promotion of carbon emissions in the surrounding areas.Energy consumption was the main obstacle to the growth of carbon emissions.④In the long run,technological progress tended to become the key to the effective implementation of potential emission reduction effects of carbon trading policies.Based on the above findings,we suggest that the construction of a national carbon trading market should be promoted,the balanced development and orderly advancement of regional carbon trading markets should be paid attention to,the coordinated development of green economy as well as knowledge and technology exchange and cooperation among regions should be strengthened to form a low carbon development model among regions.

Effects of green energy development on population growth and employment:Evidence from shale gas exploitation in Chongqing,China

With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.