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Traffic congestion is a serious problem faced by many cities worldwide today. Congestion warning information is one of the important influencing factors of urban road congestion; To this end, based on the dynamics of infectious diseases, a congestion warning information dissemination model considering the attitudes of travelers and the network structure was constructed. The existence and stability of the equilibrium points of non congestion warning information and congestion warning information in the model were analyzed, and the optimal control strategy of the model was proposed. Numerical simulation was conducted to verify the results of theoretical analysis, simulate and analyze the impact of changes in various parameters in the model on the dissemination of congestion warning information, and perform sensitivity analysis on several parameters. The results indicate that travelers are more inclined towards "fast" modes of transportation and have a stronger willingness to share congestion warning information. The dissemination range of warning information is wider, which can play a positive role in reducing traffic congestion pressure. [ABSTRACT FROM AUTHOR]

Currently, the energy dissipation efficiency of intermediate column dampers is extremely low, and traditional lever amplification damping systems occupy a large space in buildings. Aiming at solving these problems, this paper puts forward a new intermediate column–lever negative stiffness viscous damper (CLNVD), which has the characteristics of small impact on building space and significant amplification of the damper displacement. The CLNVD consists of the following four parts: the viscous damper, the negative stiffness device, the lever, and the intermediate column. This paper introduces the displacement amplification coefficient (fd) to assess the CLNVD's displacement amplification effect and introduces the energy dissipation coefficient (fE) to assess the CLNVD's energy dissipation effect. The expressions for fd and fE are derived according to the geometric magnification coefficient and effective displacement factor. Moreover, the impacts of multiple factors including the CLNVD's position, the lever's amplification coefficient, the bending line stiffness of beam, the negative stiffness, the damping coefficient, the damping index, and the inter-story displacement on the CLNVD's fd and fE are elaborated. The analysis results reveal the following: when the CLNVD is located in the middle of the span, the fd and fE of the CLNVD will be maximized, and fE will increase first and then decrease as the beam's bending line stiffness increases. Meanwhile, the amplification capability of the CLNVD increases as the lever's amplification coefficient χ rises. When the negative stiffness does not exist, there exists an optimum lever's amplification coefficient χ that maximizes fE. When the combination of damping coefficient c and index α satisfies a specific relationship, fE of the CLNVD reaches its largest value. When the negative stiffness and the loss stiffness of VD are within the region proposed in this paper, the CLNVD will achieve a higher fd and avoid providing significant negative stiffness. Subsequently, this paper proposes an optimization design method of the CLNVD. Finally, the amplification effect of CLNVD as well as the effectiveness of its optimization design method are verified through examples. In the case study, the CLNVD offers a larger damping ratio under the circumstance of fortification earthquakes. Under fortification and rare earthquakes, the inter-story displacement of Scheme 1 has been decreased by half roughly. According to the above-mentioned results, the CLNVD provides a brand-new approach for designers in the seismic design of buildings. Furthermore, this paper will provide beneficial reference for the damping design of other amplification devices equipped with negative stiffness dampers. [ABSTRACT FROM AUTHOR]

In this paper, we use the results of a survey among Slovenian politicians in order to design an objective function for an optimal control problem with a macroeconometric model for fiscal policy in Slovenia that takes account of policy makers' preferences. The paper discusses three different scenarios in which the policy preferences revealed in interviews can be included in the objective functions of the control problems. These objective functions are then used to calculate optimal fiscal policies for the Slovenian economy until 2030. For this purpose, we utilise the macroeconometric model SLOPOL10 and the OPTCON2 algorithm. The results indicate qualitatively similar behaviour of the optimised dynamic system and a better performance (lower values of the loss due to deviation from "ideal" paths) from a ranking-based approach than from an ad-hoc assumption of policy makers' preferences. We sketch how to integrate the approach in a decision-support system for macroeconomic policy design. [ABSTRACT FROM AUTHOR]

Traffic congestion is a serious problem faced by many cities worldwide today. Congestion warning information is one of the important influencing factors of urban road congestion; To this end, based on the dynamics of infectious diseases, a congestion warning information dissemination model considering the attitudes of travelers and the network structure was constructed. The existence and stability of the equilibrium points of non congestion warning information and congestion warning information in the model were analyzed, and the optimal control strategy of the model was proposed. Numerical simulation was conducted to verify the results of theoretical analysis, simulate and analyze the impact of changes in various parameters in the model on the dissemination of congestion warning information, and perform sensitivity analysis on several parameters. The results indicate that travelers are more inclined towards “fast” modes of transportation and have a stronger willingness to share congestion warning information. The dissemination range of warning information is wider, which can play a positive role in reducing traffic congestion pressure.

Urban autonomous vehicles on city roads are subject to various constraints when changing lanes, and commonly used trajectory planning methods struggle to describe these conditions accurately and directly. Therefore, generating accurate and adaptable trajectories is crucial for safer and more efficient trajectory planning. This study proposes an optimal control model for local path planning that integrates dynamic vehicle constraints and boundary conditions into the optimization problem's constraint set. Using the lane-changing scenario as a basis, this study establishes environmental and collision avoidance constraints during driving and develops a performance metric that optimizes both time and turning angle. The study employs the Gauss pseudo-spectral method to continuously discretize the state and control variables, converting the optimal control problem into a nonlinear programming problem. Using numerical solutions, variable control and state trajectories that satisfy multiple constraint conditions while optimizing the performance metric are generated. The study employs two weights in the experiment to evaluate the method's performance, and the findings demonstrate that the proposed method guarantees safe obstacle avoidance, is stable, and is computationally efficient at various interpolation points compared to the Legendre pseudo-spectral method (LPM) and the Shooting method. [ABSTRACT FROM AUTHOR]

A novel adaptive lateral optimal tracking control algorithm for real-time estimation of tire lateral stiffness was proposed. The approximate linear range of tire lateral forces were altered with variation in road surface adhesion coefficients, rendering tire lateral stiffness estimations based on linear approximations unreliable. Utilizing the recursive least squares algorithm and taking tire slip angle and lateral force as inputs, the tire's lateral stiffness was estimated in real time and an adaptive linear quadratic regulator (ALQR) controller was developed. The effectiveness and robustness of the algorithm were validated on a joint simulation platform combining Matlab/Simulink and Carsim. The results demonstrated that under various road surface adhesion conditions and at different vehicle speeds, the performance of the designed control algorithm consistently surpassed that of the traditional linear quadratic regulator (LQR) control algorithm. Specifically, the maximum lateral position error and yaw angle error were reduced by 81.5% and 73.0%, respectively. Real-vehicle tests empirically validated the practical applicability and effectiveness of the algorithm, with the maximum trajectory tracking error being only 0.56 m. [ABSTRACT FROM AUTHOR]

Currently, the energy dissipation efficiency of intermediate column dampers is extremely low, and traditional lever amplification damping systems occupy a large space in buildings. Aiming at solving these problems, this paper puts forward a new intermediate column–lever negative stiffness viscous damper (CLNVD), which has the characteristics of small impact on building space and significant amplification of the damper displacement. The CLNVD consists of the following four parts: the viscous damper, the negative stiffness device, the lever, and the intermediate column. This paper introduces the displacement amplification coefficient (fd) to assess the CLNVD’s displacement amplification effect and introduces the energy dissipation coefficient (fE) to assess the CLNVD’s energy dissipation effect. The expressions for fd and fE are derived according to the geometric magnification coefficient and effective displacement factor. Moreover, the impacts of multiple factors including the CLNVD’s position, the lever’s amplification coefficient, the bending line stiffness of beam, the negative stiffness, the damping coefficient, the damping index, and the inter-story displacement on the CLNVD’s fd and fE are elaborated. The analysis results reveal the following: when the CLNVD is located in the middle of the span, the fd and fE of the CLNVD will be maximized, and fE will increase first and then decrease as the beam’s bending line stiffness increases. Meanwhile, the amplification capability of the CLNVD increases as the lever’s amplification coefficient χ rises. When the negative stiffness does not exist, there exists an optimum lever’s amplification coefficient χ that maximizes fE. When the combination of damping coefficient c and index α satisfies a specific relationship, fE of the CLNVD reaches its largest value. When the negative stiffness and the loss stiffness of VD are within the region proposed in this paper, the CLNVD will achieve a higher fd and avoid providing significant negative stiffness. Subsequently, this paper proposes an optimization design method of the CLNVD. Finally, the amplification effect of CLNVD as well as the effectiveness of its optimization design method are verified through examples. In the case study, the CLNVD offers a larger damping ratio under the circumstance of fortification earthquakes. Under fortification and rare earthquakes, the inter-story displacement of Scheme 1 has been decreased by half roughly. According to the above-mentioned results, the CLNVD provides a brand-new approach for designers in the seismic design of buildings. Furthermore, this paper will provide beneficial reference for the damping design of other amplification devices equipped with negative stiffness dampers.

Optimal control is a common control strategy to solve complex non-linear systems. Pontryagin's minimum principle, as a typical optimal control theory, is widely used in energy management systems. Due to the randomness of new energy generation and the diversity of load power consumption, microgrid energy management system is a complex non-linear stochastic system. The efficient operation of microgrid energy management strategy largely depends on the real-time performance of the control algorithm. Pontryagin's minimum principle is an offline control strategy, whose co-state variable λ depends on expert experience and needs to be manually adjusted according to different working conditions, so it is difficult to achieve real-time optimal control. First, the energy management system model of island-type microgrid is established in this paper. In order to improve the economy of power generation and prevent battery over-charge or over-discharge, the state of charge (SOC) change of battery pack is comprehensively considered, and the fuel cost and pollutant treatment cost are taken as the objective function. Second, an adaptive Pontryagin's minimum principle energy management strategy is proposed. By introducing the penalty mechanism and adjusting the parameters adaptively, the problem that the open-loop control of Pontryagin's minimum principle needs to adjust the co-state variables in real time is solved. Comparative experiments show that compared with Pontryagin's minimum principle and particle swarm optimization, adaptive Pontryagin's minimum principle can not only limit battery SOC within the ideal range but also effectively reduce the daily operation cost of microgrid. Experimental results verify the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Problems of optimizing consumption and storage are formulated and analyzed for a small consumer whose actions do not affect the market prices of electricity. Possibilities associated with new technological and economic instruments (renewable energy sources and storage devices) are considered in the proposed models. [ABSTRACT FROM AUTHOR]

In this paper, a multi-strain coinfection model with amplification (or mutation) is established to characterize the interaction between common strain and amplified strain, as well as vaccination. The basic reproduction number ℛ0 is derived, from which the criteria on the existence and local (or global) stability of equilibria (including disease-free, dominant-strain and coexistence-strain) are established. By analyzing the effectiveness of vaccination, we find that a critical inoculation level could make the disease eliminate when ℛ0

Urban autonomous vehicles on city roads are subject to various constraints when changing lanes, and commonly used trajectory planning methods struggle to describe these conditions accurately and directly. Therefore, generating accurate and adaptable trajectories is crucial for safer and more efficient trajectory planning. This study proposes an optimal control model for local path planning that integrates dynamic vehicle constraints and boundary conditions into the optimization problem’s constraint set. Using the lane-changing scenario as a basis, this study establishes environmental and collision avoidance constraints during driving and develops a performance metric that optimizes both time and turning angle. The study employs the Gauss pseudo-spectral method to continuously discretize the state and control variables, converting the optimal control problem into a nonlinear programming problem. Using numerical solutions, variable control and state trajectories that satisfy multiple constraint conditions while optimizing the performance metric are generated. The study employs two weights in the experiment to evaluate the method’s performance, and the findings demonstrate that the proposed method guarantees safe obstacle avoidance, is stable, and is computationally efficient at various interpolation points compared to the Legendre pseudo-spectral method (LPM) and the Shooting method.

With the globalisation of the economy and the increasing interconnectedness of individuals in the financial markets, companies implementing high energy consumption strategies have become more widespread due to the "herding effect" as they become more closely linked for development. In the context of carbon neutrality, the issue of how to reduce the spread of high energy consumption strategies and the issue surrounding the governance of corporate emissions have become a focus of research. This paper uses the improved SEIJRS infectious disease model to investigate the phenomenon of corporate high energy strategy infection, combined with optimal control theory, to provide a reference for governments and regulators to develop reasonable optimal prevention and control strategies. [ABSTRACT FROM AUTHOR]

This article discusses the embodiment of a vector system of asynchronous motor control using MATLAB/Simulink. The control circuit of flux linkage has been supplemented, with the setting value of rotor flux linkage being formed at the output of an online optimizer. An extremum-seeking controller has been considered in MATLAB/Simulink, and parameterization of the elements of the flux-linkage controller has been described. The implemented method and scalar control system are compared in terms of power-efficiency criteria. The criteria are the active power, total power, and power coefficient. The data obtained by simulation have been analyzed, as a result of which it is concluded conclusion that the proposed method is appropriate for improving the power efficiency of a submersible electrical motor. The advantages of the implemented control method include simplicity of embodiment and the absence of gradient methods of optimization and algorithms requiring high computational capacity when reproduced on actual equipment. [ABSTRACT FROM AUTHOR]

In the last decade, the rapid and successful development of reusable launch systems such as SpaceX' Falcon 9 demonstrated both the operational feasibility of reusable launchers and their economic viability. The objective of recovering a launcher or a launcher's booster requires to safely return the launch vehicle from orbital or sub-orbital conditions to a soft landing. To increase the reusability, decrease the turnaround time and reduce costs, a precise touchdown on a pre-defined landing site or on a floating barge on the Ocean is preferred to splashdown in the water, due mainly to the highly detrimental effect of the salted water on the launcher components and equipment. The project RETALT (Retro Propulsion Assisted Landing Technologies) was funded by the EU Horizon 2020 program to study and develop critical technologies for launcher recovery based on retro-propulsion. In this context, and based on in-house experience and tools, DEIMOS Space carried out the mission engineering of the RETALT1 vehicle concept to assess the feasibility of a return mission, from a wide range of Main Engine Cut-Off (MECO) conditions, when the stage is separated from the rest of the launch vehicle, in line with the available propellant budget, and while maintaining the peak entry conditions within acceptable limits. Either a DownRange Landing (DRL) on a drone ship at sea or a Return To Launch Site (RTLS) to land in the proximity of the launch pad is performed based on the velocity and distance at MECO from the launch site. For the landing burn, a safe splashdown approach has been implemented to avoid damaging the ground infrastructure in case of anomalies during the flight. Based on the mission feasibility assessment, the needs for the vehicle recovery have been identified, leading to the definition of preliminary mission requirements at the system and subsystem level. Consequently, the consolidation of the return mission design was possible and optimised trajectories have been defined for the DRL and RTLS scenarios. [ABSTRACT FROM AUTHOR]

Liquid hydrogen plays a crucial role in the large-scale storage and long-distance transportation of hydrogen energy. Effectively controlling hydrogen turbo-expanders is an important strategy for reducing energy consumption during liquefaction process. This study conducts both experimental and numerical investigations on a hydrogen turbo-expander within a 5 t/d hydrogen liquefaction system. A CFD model is developed to predict the performance of hydrogen turbo-expanders, which is then validated against experimental data. The numerical predictions of isotropic efficiency closely match experimental results, with a maximum deviation of 10 %. Throughout the cooling-down process, the efficiency of the hydrogen turbo-expander varies significantly, indicating a strong dependence on the characteristic ratio. Consequently, an optimal characteristic ratio method is proposed to maintain the hydrogen turbo-expander at peak efficiency. Compared to traditional control methods based on fixed brake pressure, the proposed approach achieves a maximum efficiency enhancement of 23.8 %. At the optimal characteristic ratio, the rotational speed can be maintained at the design level by adjusting brake pressure, which remains below the design value during the cooling-down phase. This investigation presents an effective method for optimizing the control of turbo-expanders in hydrogen liquefaction systems. • A coupling operation model of hydrogen turbo-expander is validated by experiment. • Deviations from design characteristic ratio lead to significant efficiency drop. • Optimum characteristic ratio method improves operation efficiency by 23.8 %. [ABSTRACT FROM AUTHOR]

Effective balanced management of battery packs can not only increase the available capacity of a battery pack but reduce attenuation and capacity loss caused by cell inconsistencies and remove safety hazards caused by abnormal use such as overcharge and over-discharge. This research considers both the equilibration period and the battery operating current. The State of Charge (SOC), current, and equalization current of batteries are all limited. Based on the existing multi-layer equalization model, the equalization current of the equalizer was tuned with restrictions. It can equalize multiple batteries simultaneously and ensure the normal operation of the batteries. A layered control strategy was then found to solve the optimal equalization current of the equalizer layer by layer. The proposed control method reduces computation time and guarantees that the equalization approach can be employed in practice. Finally, through MATLAB simulation analysis, this technique can limit the cell current to (−3 A, 3 A), which improves the balancing efficiency by 23.55% compared with the balancing of adjacent cells. [ABSTRACT FROM AUTHOR]

Based on the energy storage cloud platform architecture, this study considers the extensive configuration of energy storage devices and the future large-scale application of electric vehicles at the customer side to build a new mode of smart power consumption with a flexible interaction, smooth the peak/valley difference of the load side power, and improve energy efficiency. A plug and play device for customer-side energy storage and an internet-based energy storage cloud platform are developed herein to build a new intelligent power consumption mode with a flexible interaction suitable for ordinary customers. Based on the load perception of the power grid, this study aims to investigate the operating state and service life of distributed energy storage devices. By selecting an integrated optimal control scheme, this study designs a kind of energy optimization and deployment strategy for stratified partition to reduce the operating cost of the energy storage device on the client side. The effectiveness of the system and the control strategy is verified through the Suzhou client-side distributed energy storage demonstration project.

The possibility of effective application of variational methods to the solution of problems on optimum control of decrease in the intensity of the temperature perturbations of the surroundings of devices, attained with the use of heterogeneous laminated composition coatings, was investigated. In the process of investigating the conditions of optimum control of the intensity of a temperature field with the use of a heterogeneous laminated composition construction, qualitative relations between the parameters of such a construction, which allows one to estimate its efficiency and potentials, have been obtained. [ABSTRACT FROM AUTHOR]

Social media plays a crucial role in controlling the epidemic spreading by creating awareness. Epidemic spreading processes over the multiplex network where epidemic spreading in one layer and awareness spreading in another layer, are well suitable to study the spreading of infection in a small region. Using the Microscopic Markov chain approach (MMCA), the dynamical interplay between the spreading of epidemics over the physical contact layer and human awareness diffusion over the virtual contact layer over a multiplex network framework is analyzed. SEIR process for epidemic spreading and UAU process for awareness diffusion are assumed to study the spreading process of COVID-19. The basic-reproduction number R 0 is determined using the next generation matrix approach. The stability of disease-free equilibrium (DFE) and endemic equilibrium (EE) is analyzed. Using Pontryagins Minimum Principle, optimal parametric values are determined analytically for testing and cleaning the virus-contaminated surfaces. The impact of various parameters over the epidemic spread is analyzed numerically. Through numerical illustrations, the effect of early identification of exposed people and immediate cleaning of virus-contaminated surfaces over R 0 studied. The sensitivity analysis is performed to show the importance of wearing face-mask, following social distancing, washing hands frequently and, avoiding unnecessary travel. Through numerical simulations, the results obtained coincide with real data of COVID-19 spreading in the city Chennai, India. The results obtained show that in order to control or discard the spreading of COVID-19, each people should follow the self-preventive measures without relaxation till the epidemic comes nearer to the disease free state. [ABSTRACT FROM AUTHOR]

Effective balanced management of battery packs can not only increase the available capacity of a battery pack but reduce attenuation and capacity loss caused by cell inconsistencies and remove safety hazards caused by abnormal use such as overcharge and over-discharge. This research considers both the equilibration period and the battery operating current. The State of Charge (SOC), current, and equalization current of batteries are all limited. Based on the existing multi-layer equalization model, the equalization current of the equalizer was tuned with restrictions. It can equalize multiple batteries simultaneously and ensure the normal operation of the batteries. A layered control strategy was then found to solve the optimal equalization current of the equalizer layer by layer. The proposed control method reduces computation time and guarantees that the equalization approach can be employed in practice. Finally, through MATLAB simulation analysis, this technique can limit the cell current to (−3 A, 3 A), which improves the balancing efficiency by 23.55% compared with the balancing of adjacent cells.

In order to avoid an obstacle automatically for an automated vehicle, this paper investigated a method to generate a target trajectory using a clothoid curve and to control the vehicle. Although a mathematical constraints or a potential methods are often used to generate the target trajectory for an obstacle avoidance, it requires trial and error and experience, and it is also necessary to consider the vehicle’s drivability. The clothoid curve is often used for a road curve design, therefore, the curve is considered to be suitable for the characteristics of a vehicle driving. Although a clothoid curve passing through a target point is necessary for obstacle avoidance, such clothoid curve is often obtained by trial and error. Therefore, the numerical analyses were executed to obtain the characteristics of the clothoid curve, then, the method was investigated to generate the clothoid curve to pass through the target point. Furthermore, a method to generate a target avoidance trajectory was also investigated expanding the generated clothoid curve based on the traveling characteristics of a vehicle. For driving on the target trajectory satisfactory, both the position and turning angle of the vehicle are controlled by means of a steering manuplation. The controller was constructed using a 1-input 2-output system, therefore, it is very difficult to satisfy both value at the same time. Furthermore, it is also necessary to consider a nonholonomic characteristics of the vehicle. From these point, this paper investigated the optimal control using nonlinear least square probrem sequential quadratic programming(NLSSQP) by means of the time behaviour of input and output in the evaluation value. Well expected results are obtained and shown in the simulation and the experiment.

The increase in population especially in third world countries demands taller, more flexible, and lighter buildings. Most of these countries are subjected to a high risk of earthquakes, which requires more control of building seismic response. However, several techniques exist to minimize the vibrations induced by an earthquake shock. This paper will discuss the effectiveness of using friction dampers as a passive dissipative device and proposes some design optimization of the number and position of dampers in the building. Friction dampers offer a supplemental damping in conjunction with appropriate stiffness, offering an innovative and attractive solution for the seismic response control of tall structures in risky areas. The originality of this work is in the detailed seismic study of an asymmetric reinforced concrete (RC) building, located in a risky seismic zone and using real earthquake seismic waves. The seismic response of this dissipative structural method is compared with the response of the conventional method (shear wall system) for the high rise building. To accomplish this objective, a nonlinear modal time history analysis using the El Centro earthquake record for a 40‐storey RC high rise building, is performed with four different damper type formats using ETABS software. To illustrate the response improvement by dampers, storey accelerations, storey displacements, base shear forces, and storey drifts are compared with a conventional fixed base system (shear wall system) for the same building. Results show that using an optimum position and number of dampers, a tall building can remain operational during a seism.

Linear controlled multistep processes are considered with an additive quality functional under a phase constraint and a terminal condition. These processes are of interest for control theory and its applications. An existence theorem for optimum control is proved for the controlled processes under consideration. In analogy with backward constructions in the positional theory of differential games developed to solve positional differential pursuit games, a procedure for geometric splitting is developed for optimizing the considered problems that is characteristic of the theory of dynamic programming. [ABSTRACT FROM AUTHOR]

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An -dimensional economic model is considered that has a Cobb–Douglas production function on the infinite planning horizon such that the utility function is an integral-type functional with a discount and a logarithm-type integrant. It is assumed that all of the model's amortization factors are equal to one another. The constructed optimum control contains special segments that are described analytically. A special sweep procedure for consecutively solving two Cauchy problems on each segment is developed to find moments of switching between segments and the shape of the optimum trajectory. On the last segment, the optimum trajectory lies along a special ray; from the viewpoint of economy, this ray can be interpreted as the mode of equilibrium growth. A Pontrjagin maximum-principle problem with a special transversality condition is used to construct the optimum solution. Optimality is confirmed using the Kiselev theorem on sufficient conditions. Moving to problems of large dimensions considerably increases the number of technical difficulties. The description of the optimality verification procedure is therefore presented in detail for methodological reasons. [ABSTRACT FROM AUTHOR]

As an important content in intelligent vehicle technology, the design of lane changing path directly decides the quality of control in autonomous lane changing realization. This paper first summarizes the design principle of existing intelligent vehicle lane changing techniques. Then a novel lane changing path based on the X-Sin function is constructed. The X-Sin function is designed to combine the outstanding smoothness of sine function and the linear characteristic of the constant-speed shift function. With parameters including vehicle velocity, lane width and the maximum lateral acceleration, the proposed design solves the problems in lane changing path including jump point in lane changing path curvature and non-smooth lane changing path. A tracking controller is designed using quadratic optimum control to track the lane changing path. The effectiveness and steadiness of the proposed lane changing path is demonstrated by MATLAB simulation and real-vehicle experiments. [ABSTRACT FROM AUTHOR]

In this study, we used a simple epidemic model and 2015-16 outbreak data of Chikungunya, Dengue and Zika viruses, arthropod mediated infections that are transmitted by the common mosquito vector Aedes aegypti, from Mexico to quantify the transmission rates (humans-to-mosquitoes and mosquitoes-to-humans) of the three diseases. The transmission rates are estimated for the observed data and consequently the basic reproduction number R[sub 0] is calculated 6.740, 2.904 and 12.6283 for Chikungunya, Dengue and Zika infection, respectively. Using the estimated parameters for the three diseases, we evaluated self-imposed controls measures by the population as a result of fear-driven behavior changes often seen during an outbreak. Furthermore, the sensitivity analysis reveals that the parameter 'mosquitoes death rate' is the most sensitive one for R[sub 0]. Simulations of controlled basic reproduction number are also performed for all considered control measures. This study is likely to enrich the understanding about transmission of such viral infections and control strategies. [ABSTRACT FROM AUTHOR]

Deep sea mining, as a frontier area in China, urgently needs to make progress in automatic navigation technology. In order to improve the operation efficiency of the seabed mining machine on the soft seabed, the submarine mining vehicle which complete the mining work in a certain mining area need to enter the next mining area quickly and economically. As a classical algorithm, the majority of scholars consider that A * algorithm is the most practical path planning search algorithm. Considering the limitation of operation conditions, the three-dimensional diagram is transformed into two-dimensional diagram by interpolation method when the seabed terrain conditions allow, and then the obstacles can be marked in two-dimensional diagram. A* algorithm was applied into the path planning of mining truck. The simulation results of the paper show that path cost, turning time and turning mode should be considered in the process of avoiding obstacles.

Once a combined vehicle becomes unstable, it is very difficult for a driver to stabilize it especially under severe driving conditions, such as turning with braking. This is mainly due to the effect of the towed vehicle on the towing vehicle through the hitch jackknifing. This effect makes the handling characteristics of a car-caravan combination different from those of a single vehicle. Therefore, this paper proposes a control design concept for an optimum distribution of longitudinal and lateral forces of the four tires of a towing vehicle. The mean objectives of the control system were to stabilize the motion of an articulated vehicle utilizing the tires entire ability in both longitudinal and lateral directions as well as to make the handling characteristics of an articulated vehicle similar to those of a single one. The sliding control law based on vehicle planar equations of motion is used to derive the control laws. The proposed control system is evaluated under severe driving conditions and compared with the results of integrated control systems. The robustness of the articulated vehicle motion with the proposed control against the coefficient of friction variation is discussed.

Friction-based structural control is an available strategy for reducing the seismic response of buildings. The friction dampers in such systems can be operated using passive and semiactive control. Passive dampers with constant, pre-defined capacity are effective and simple, but their adaptability to a broad range of frequency excitations is limited and their optimal configuration is complex. Semiactive control provides a means to vary the dampers’ capacity to their optimum levels in real-time, but time delays in the control action may affect their performance. In this investigation, a passive system is initially introduced in a multi-storey steel frame to identify a threshold of optimum control force demand related to the limits of the building’s elastic response. A new semiactive algorithm is then introduced to adjust the dampers’ capacity based on the current deformation state across the building. From simulations of the non-linear response of the frame, the semiactive system reduced the structural response to levels similar to the optimum passive control, with more uniform distributions of storey drift. The control system had optimum performance when a range of time delays was included to simulate different regulator mechanisms. [ABSTRACT FROM AUTHOR]

Naval propulsion is facing mutations toward electrification of propulsion system. In naval propulsion applications, motors and drives are required to be highly fault tolerant. For reasons such as reliability, smooth torque and partition of power multiphase motors appears to good candidates for electrical marine propulsion. Permanent magnet machines are preferred over others because of their higher power densities and efficiencies, allowing a more compact and efficient propulsion system design. In this paper, a comparison between two open-circuit fault-tolerant control techniques for 5-phase permanent magnet machines (PMSM) with trapezoidal back EMF is presented. The first technique is an off-line one based on the instantaneous power balance and the Joule losses minimization theory. The second technique is an on-line one based on the minimization of copper losses, as this point appears to be particularly relevant for ship propulsion. The objective of these two techniques is to achieve ripple-free torque with minimum Joule losses. Firstly, the dynamic model of the 5-phase PMSM with trapezoidal back-EMF is given. Then detailed derivation of both control techniques and current reference extraction are presented. Finally, simulation and experimental results on a low-power laboratory test bench are presented and discussed. [ABSTRACT FROM AUTHOR]

The main objective of this paper is the design of an Electric Naval Propulsion System (ENPS) emulator based on a low power multiphase machine. The whole drive system (control, power electronics, and electric machine) is tested and the mechanical part is emulated based on a Hardware-in-the-Loop principle. First, the modeling of all system components including mechanical and electrical parts are reviewed, and the total hull resistance forces are also developed. Then, a pure software simulation of the ENPS is carried out. After that, the designed emulator architecture is presented, and for adaption purpose, a scaling factor is introduced. The developed emulation tool allows to validate optimal control strategies for the propulsion system under a realistic navigation cycle under healthy and faulty operating conditions. Finally, simulation and experimental results are compared to investigate the accuracy and the performance of the developed emulator, and the effectiveness of the proposed control strategies. [ABSTRACT FROM AUTHOR]

In this paper, a multi-strain coinfection model with amplification (or mutation) is established to characterize the interaction between common strain and amplified strain, as well as vaccination. The basic reproduction number ℛ 0 is derived, from which the criteria on the existence and local (or global) stability of equilibria (including disease-free, dominant-strain and coexistence-strain) are established. By analyzing the effectiveness of vaccination, we find that a critical inoculation level could make the disease eliminate when ℛ 0 < 1 , while inefficient vaccines could cause backward bifurcation when ℛ 0 < 1. Based on sensitivity analysis and realistic control policy, the optimal strategy of disease control is obtained. The theoretical results are illustrated by numerical simulation and clinical data of COVID-19 in Morocco. • SVIR mathematical model with amplification including vaccination to fight the multi-strain disease. • The dynamics and optimal control strategy of disease are obtained. • Inefficient vaccines can cause backward bifurcation. • Multi-strain disease spread can be minimized through vaccination as a control measure. [ABSTRACT FROM AUTHOR]

The paper introduces methods of dynamic games for automation of ship control in the collision situation, the game control processes in marine navigation and the fundamental mathematical model of the game ship control. First, state equations, control and state constraints and then control goal function in the form of payments: the integral payment and the final one, have been defined. Multi-stage positional, and multi-step matrix, non-cooperative and cooperative, game and optimum control algorithms for a collision situation, have been presented. Te considerations have been illustrated with an exemplary computer simulation of algorithms to determine a safe own ship's trajectory in the process of passing the ships encountered in Kattegat Strait.