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This theoretical study seeks to extend the concept of fractional Jeffrey fluid and heat transfer near an infinite vertical plate, governed by generalized boundary conditions, using a time-fractional Prabhakar operator. Initially, the momentum equation incorporating the fractional Jeffrey model is developed to examine the unsteady flow, focusing on pressure dynamics within the boundary layer. Additionally, the energy equation, along with convective heat and mass transfer under generalized conditions, is formulated using the extended Fourier's law. The Prabhakar fractional operator is utilized to represent the fluid's transport mechanisms. The study presents fractional governing equations to describe heat, mass, and flow transfer processes influenced by magnetic fields and radiation effects. A Prabhakar fractional derivative is applied to model the fractional system, and analytical solutions are derived using the Laplace transform technique. The accuracy and validity of the results are confirmed by comparing them with previous work and exact solutions. Furthermore, the strong agreement between our analytical solutions and earlier studies reinforces the method's reliability. The effects of various parameters on the fluid's velocity, mass, and temperature distribution are demonstrated graphically. Changes in the model's parameters result in varying trends in the velocity, mass, and temperature profiles, highlighting the critical impact of each parameter on the behavior of fluid flow, mass, and heat transfer. [ABSTRACT FROM AUTHOR]

In this article, a new approach to study the fractionalized second grade fluid flow is described by the different fractional derivative operators near an exponentially accelerated vertical plate together with exponentially variable velocity, energy and mass diffusion through a porous media is critically examined. The phenomenon has been expressed in terms of partial differential equations, then transformed the governing equations in non-dimentional form. For the sake of better rheology of second grade fluid, developed a fractional model by applying the new definition of Constant Proportional-Caputo hybrid derivative (CPC), Atangana Baleanu in Caputo sense (ABC) and Caputo Fabrizio (CF) fractional derivative operators that describe the generalized memory effects. For seeking exact solutions in terms of Mittag-Leffler and G-functions for velocity, temperature and concentration equations, Laplace integral transformation technique is applied. For physical significance of various system parameters on fluid velocity, concentration and temperature distributions are demonstrated through various graphs by using graphical software. Furthermore, for being validated the acquired solutions, accomplished a comparative analysis with some published work. It is also analyzed that for exponential heating and non-uniform velocity conditions, the CPC fractional operator is the finest fractional model to describe the memory effect of velocity, energy and concentration profile. Moreover, the graphical representations of the analytical solutions illustrated the main results of the present work. Also, in the literature, it is observed that to derived analytical results from fractional fluid models developed by the various fractional operators, is difficult and this article contributing to answer the open problem of obtaining analytical solutions the fractionalized fluid models. [ABSTRACT FROM AUTHOR]

This theoretical study seeks to extend the concept of fractional Jeffrey fluid and heat transfer near an infinite vertical plate, governed by generalized boundary conditions, using a time-fractional Prabhakar operator. Initially, the momentum equation incorporating the fractional Jeffrey model is developed to examine the unsteady flow, focusing on pressure dynamics within the boundary layer. Additionally, the energy equation, along with convective heat and mass transfer under generalized conditions, is formulated using the extended Fourier’s law. The Prabhakar fractional operator is utilized to represent the fluid’s transport mechanisms. The study presents fractional governing equations to describe heat, mass, and flow transfer processes influenced by magnetic fields and radiation effects. A Prabhakar fractional derivative is applied to model the fractional system, and analytical solutions are derived using the Laplace transform technique. The accuracy and validity of the results are confirmed by comparing them with previous work and exact solutions. Furthermore, the strong agreement between our analytical solutions and earlier studies reinforces the method’s reliability. The effects of various parameters on the fluid’s velocity, mass, and temperature distribution are demonstrated graphically. Changes in the model’s parameters result in varying trends in the velocity, mass, and temperature profiles, highlighting the critical impact of each parameter on the behavior of fluid flow, mass, and heat transfer.

Low-frequency oscillation (LFO) poses significant challenges to the dynamic performance of hydropower unit regulation systems (HURS) in hydropower units sharing a tailwater system. Previous methods have struggled to effectively suppress LFO, due to limitations in governor parameter optimization strategies. To address this issue, this paper proposes a governor parameter optimization strategy based on the crayfish optimization algorithm (COA). Considering the actual water diversion layout (WDL) of a HURS, a comprehensive mathematical model of the WDL is constructed and, combined with models of the governor, turbine, and generator, an overall HURS model for the shared tailwater system is derived. By utilizing the efficient optimization performance of the COA, the optimal PID parameters for the HURS controller are quickly obtained, providing robust support for PID parameter tuning. Simulation results showed that the proposed strategy effectively suppressed LFOs and significantly enhanced the dynamic performance of the HURS under grid-connected conditions. Specifically, compared to before optimization, the optimized system reduced the oscillation amplitude by at least 30% and improved the stabilization time by at least 25%. Additionally, the impact of the power grid system parameters on oscillations was studied, providing guidance for the optimization and tuning of specific system parameters. [ABSTRACT FROM AUTHOR]

Current condition monitoring of three-phase inverters is mainly for DC-link capacitance, with little attention paid to AC-side parameters, and some of these methods require the addition of DC current sensors or changes in operating conditions. In fact, the AC side inductance degrades with use. In particular, the neutral inductors of three-phase four-wire inverters need to be condition-monitored because of the high failure rate due to the long term exposure to huge ripples. To address the above problems, this paper proposes a zero-sequence current injection method, which can take into account both the AC and DC sides, satisfy the parameter identification of “large capacitance and small inductance”, and does not need to add additional sensors or sampling circuits. Then, the zero-sequence components are extracted by a high-order band-pass filter and a recursive least squares filter. Next, the extracted components are processed by the proposed adaptive forgetting factor recursive least square observer to obtain the recognized parameter values. The speed and accuracy of parameter identification are greatly accelerated by the adaptive processing of the forgetting factor. The three-phase simultaneous identification and back-propagation iteration for the neutral inductor improves the identification accuracy and speed. Finally, a three-phase four-wire experimental platform is built. The experimental results show that the proposed method is still effective under different types of loads and load fluctuation.© 2017 Elsevier Inc. All rights reserved.

Dedicated to synchronously acquiring large-area, high-precision, and multi-scale ocean wind and wave information, a novel concept of a spaceborne ocean microwave dual-function integrated sensor is proposed in this paper. It integrates the functions of a scatterometer and SAR by sharing a single phased-array antenna. An overview of the scientific requirements and motivations for the sensor are outlined firstly. In order to fulfill the observation requirements of both the functions, the constraints on the system parameters such as frequency, antenna size, and incidence angle are analyzed. Then, the selection principles of these parameters are discussed within the limitations of antenna area, bandwidth, available time, and cost. Additionally, the constraints on the time sequence of transmitting and receiving pulses are derived to ensure that there is no conflict when the two functions operate simultaneously. Subsequently, a method for jointly designing the pulse repetition frequency (PRF) of both the functions is introduced, along with zebra maps to verify its effectiveness. At the end of the paper, the system and performance parameters of the sensor are given for further insight into it. [ABSTRACT FROM AUTHOR]

Low-frequency oscillation (LFO) poses significant challenges to the dynamic performance of hydropower unit regulation systems (HURS) in hydropower units sharing a tailwater system. Previous methods have struggled to effectively suppress LFO, due to limitations in governor parameter optimization strategies. To address this issue, this paper proposes a governor parameter optimization strategy based on the crayfish optimization algorithm (COA). Considering the actual water diversion layout (WDL) of a HURS, a comprehensive mathematical model of the WDL is constructed and, combined with models of the governor, turbine, and generator, an overall HURS model for the shared tailwater system is derived. By utilizing the efficient optimization performance of the COA, the optimal PID parameters for the HURS controller are quickly obtained, providing robust support for PID parameter tuning. Simulation results showed that the proposed strategy effectively suppressed LFOs and significantly enhanced the dynamic performance of the HURS under grid-connected conditions. Specifically, compared to before optimization, the optimized system reduced the oscillation amplitude by at least 30% and improved the stabilization time by at least 25%. Additionally, the impact of the power grid system parameters on oscillations was studied, providing guidance for the optimization and tuning of specific system parameters.

Free space optics (FSO) is a novel transmission technique capable of providing high-capacity links with large bandwidth and robustness against electromagnetic waves interference. In this work, we demonstrate the development of a 100 Gbps FSO link which employs the hybridization of polarization division multiplexing technique and coherent detection-orthogonal frequency division multiplexing technique. Further, we have investigated the system performance by varying different parameters like the input power, the size of the receiver antenna, wavelength of laser beam, the angle of beam divergence, and the additional losses. The proposed system has been modeled and analyzed over Optisystem test bed. [ABSTRACT FROM AUTHOR]

A cascade refrigeration system consists of two cycles to get the greatest possible refrigeration effect for applications requiring extremely low temperatures. The experimental examination of the cascade refrigeration system utilized for quickly freezing and storing blood products, notably plasma, was the main emphasis of this paper. This system is able to manage and apply cold storage for plasma at temperatures as low as -35oC. R410A (low temperature cycle) and R404A (high temperature cycle) are the working fluids in this system respectively, and their selection was based on their reasonable boiling point differences and rapid freezing times. These working fluids have very little ozone depletion and global warming potential, and they are non-toxic to the environment. This system performance evaluation determines the cascade refrigeration system's parameters ranging effects of variation in evaporator temperature, condenser temperature and temperature difference in cascade condenser. As the evaporator temperature increases from – 35oC to -70C at interval of 7oC, the suction pressure increased from 0.22 MPa to 0.64 MPa. The decrease in compressor discharge temperature of 30oC to 26oC resulted to decrease in discharge pressure ranging 1.62 to 1.49MPa in the high temperature cycle at constant condenser temperature of 40 0C. At varying heat exchanger temperature, all parameters reduced with exception of discharge temperature in both cycles and evaporator heat. A substantial increase in the coefficient of performance of comparable systems was found to be 3.04 (LTC) and 7.7 (HTC). At the high temperature cycle condenser, there was a total heat rejection of 6228 kJ, which could then be recycled for heating.

A new approach is used to investigate the analytical solutions of the mathematical fractional Casson fluid model that is described by the Constant Proportional Caputo fractional operator having non-local and singular kernel near an infinitely vertical plate. The phenomenon has been expressed in terms of partial differential equations, and the governing equations were then transformed in non-dimensional form. For the sake of generalized memory effects, a new mathematical fractional model is formulated based on the newly introduced Constant Proportional Caputo fractional derivative operator. This fractional model has been solved analytically, and exact solutions for dimensionless velocity, concentration and energy equations are calculated in terms of Mittag-Leffler functions by employing the Laplace transformation method. For the physical significance of various system parameters such as α, β, Pr, Gr, Gm, Sc on velocity, temperature and concentration profiles, different graphs are demonstrated by Mathcad software. The Constant Proportional Caputo fractional parameter exhibited a retardation effect on momentum and energy profile, but it is visualized that for small values of Casson fluid parameter, the velocity profile is higher. Furthermore, to validated the acquired solutions, some limiting models such as the ordinary Newtonian model are recovered from the fractionalized model. Moreover, the graphical representations of the analytical solutions illustrated the main results of the present work. Also, from the literature, it is observed that to deriving analytical results from fractional fluid models developed by the various fractional operators is difficult, and this article contributes to answering the open problem of obtaining analytical solutions for the fractionalized fluid models.

Physics-informed neural networks (PINNs) have emerged as a promising deep learning method, capable of solving forward and inverse problems governed by differential equations. Despite their recent advance, it is widely acknowledged that PINNs are difficult to train and often require a careful tuning of loss weights when data and physics loss functions are combined by scalarization of a multi-objective (MO) problem. In this paper, we aim to understand how parameters of the physical system, such as characteristic length and time scales, the computational domain, and coefficients of differential equations affect MO optimization and the optimal choice of loss weights. Through a theoretical examination of where these system parameters appear in PINN training, we find that they effectively and individually scale the loss residuals, causing imbalances in MO optimization with certain choices of system parameters. The immediate effects of this are reflected in the apparent Pareto front, which we define as the set of loss values achievable with gradient-based training and visualize accordingly. We empirically verify that loss weights can be used successfully to compensate for the scaling of system parameters, and enable the selection of an optimal solution on the apparent Pareto front that aligns well with the physically valid solution. We further demonstrate that by altering the system parameterization, the apparent Pareto front can shift and exhibit locally convex parts, resulting in a wider range of loss weights for which gradient-based training becomes successful. This work explains the effects of system parameters on MO optimization in PINNs, and highlights the utility of proposed loss weighting schemes.

Dedicated to synchronously acquiring large-area, high-precision, and multi-scale ocean wind and wave information, a novel concept of a spaceborne ocean microwave dual-function integrated sensor is proposed in this paper. It integrates the functions of a scatterometer and SAR by sharing a single phased-array antenna. An overview of the scientific requirements and motivations for the sensor are outlined firstly. In order to fulfill the observation requirements of both the functions, the constraints on the system parameters such as frequency, antenna size, and incidence angle are analyzed. Then, the selection principles of these parameters are discussed within the limitations of antenna area, bandwidth, available time, and cost. Additionally, the constraints on the time sequence of transmitting and receiving pulses are derived to ensure that there is no conflict when the two functions operate simultaneously. Subsequently, a method for jointly designing the pulse repetition frequency (PRF) of both the functions is introduced, along with zebra maps to verify its effectiveness. At the end of the paper, the system and performance parameters of the sensor are given for further insight into it.

A new approach is used to investigate the analytical solutions of the mathematical fractional Casson fluid model that is described by the Constant Proportional Caputo fractional operator having non-local and singular kernel near an infinitely vertical plate. The phenomenon has been expressed in terms of partial differential equations, and the governing equations were then transformed in non-dimensional form. For the sake of generalized memory effects, a new mathematical fractional model is formulated based on the newly introduced Constant Proportional Caputo fractional derivative operator. This fractional model has been solved analytically, and exact solutions for dimensionless velocity, concentration and energy equations are calculated in terms of Mittag-Leffler functions by employing the Laplace transformation method. For the physical significance of various system parameters such as α, β, Pr, Gr, Gm, Sc on velocity, temperature and concentration profiles, different graphs are demonstrated by Mathcad software. The Constant Proportional Caputo fractional parameter exhibited a retardation effect on momentum and energy profile, but it is visualized that for small values of Casson fluid parameter, the velocity profile is higher. Furthermore, to validated the acquired solutions, some limiting models such as the ordinary Newtonian model are recovered from the fractionalized model. Moreover, the graphical representations of the analytical solutions illustrated the main results of the present work. Also, from the literature, it is observed that to deriving analytical results from fractional fluid models developed by the various fractional operators is difficult, and this article contributes to answering the open problem of obtaining analytical solutions for the fractionalized fluid models. [ABSTRACT FROM AUTHOR]

• A new linear solenoid elastic actuator (LSEA) with high stiffness is analyzed. • A new analytical model describing axial magnetic field distribution is proposed. • The proposed analytical model has advantages in accuracy and calculation speed. • A composite model with viscous and hysteres damping is developed. In order to improve the dynamic performance and load resistance of linear electromagnetic actuators, a novel linear solenoid elastic actuator with higher nonlinear negative stiffness and speed is proposed. In this paper, the nonlinear force–displacement relationship and transient performance of the actuator is analyzed and predicted. The analytical, numerical and finite element methods are used to establish and solve the electromagnetic–mechanical coupling model. First, the approximate analytical model of the electromagnetic force is derived by constructing an innovative axial magnetic field distribution model. Second, the transient dynamic model considering viscous and hysteretic damping is established and solved theoretically to obtain the performance indicators and system parameters. Finally, the transient displacements and performance indicators obtained from the analytical model, the numerical model, the finite element simulation and the experiment are compared. The maximum errors of the peak time, overshoot, setting time and stable displacement through the analytical model and experiment are 3.16 ms, 6.6 %, 76.3 ms and 0.16 mm, respectively. The theoretical and experimental results show the nonlinear effects of input currents on performance indicators and system parameters. The actuator can produce a displacement of 8.7 mm against a load of 20 g at a voltage of 8.8 V. The mass of the load is 2.94 times that of the actuator. Through the theoretical and experimental analysis, high negative stiffness provides better transient response and driving characteristics for linear electromagnetic actuators. This research provides a reference for the transient solution of nonlinear electromagnetic-dynamic coupling models and performance improvement of linear electromagnetic actuators. [ABSTRACT FROM AUTHOR]

• The actual duty cycle function is derived by considering the effects of dead time, on-time and off-time in the dual sampling mode, and based on this, the capacitor current, three-phase inductance and neutral inductance voltage numerical sums are constructed, respectively. • The injection method of the third current is proposed. The third current is unobstructed as a zero-sequence component both in the DC side and the AC side. If the third current is injected in three phases at the same time, then a current component equivalent to three times of the single-phase injection is generated in the DC capacitor, which is also sufficient to generate a large DC-side third-order voltage variation. • For capacitor identification, a AFFRLS method is proposed, and an expression for the forgetting factor adaption is given. The proposed method achieves 3% capacitance steady-state discrimination accuracy and can reach ±3% discrimination error range within 0.2s with fast response speed. • For inductor identification, based on the AFFRLS, a three-phase averaging method is adopted for the identification of the neutral inductor, and the averaging is carried out after iterative updating of the forgetting factor. Current condition monitoring of three-phase inverters is mainly for DC-link capacitance, with little attention paid to AC-side parameters, and some of these methods require the addition of DC current sensors or changes in operating conditions. In fact, the AC side inductance degrades with use. In particular, the neutral inductors of three-phase four-wire inverters need to be condition-monitored because of the high failure rate due to the long term exposure to huge ripples. To address the above problems, this paper proposes a zero-sequence current injection method, which can take into account both the AC and DC sides, satisfy the parameter identification of "large capacitance and small inductance", and does not need to add additional sensors or sampling circuits. Then, the zero-sequence components are extracted by a high-order band-pass filter and a recursive least squares filter. Next, the extracted components are processed by the proposed adaptive forgetting factor recursive least square observer to obtain the recognized parameter values. The speed and accuracy of parameter identification are greatly accelerated by the adaptive processing of the forgetting factor. The three-phase simultaneous identification and back-propagation iteration for the neutral inductor improves the identification accuracy and speed. Finally, a three-phase four-wire experimental platform is built. The experimental results show that the proposed method is still effective under different types of loads and load fluctuation. © 2017 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of electromagnetic induction coil launcher (EICL) system parameters on the launch performance was analyzed, and a method for measuring the launch performance of an EICL system with a muzzle velocity and energy conversion efficiency was proposed. The EICL system mainly includes a pulse power supply and launcher. The parameters of the pulse power supply mainly include the discharge voltage and the capacitance value of the capacitor bank. The structural parameters of the launcher mainly include the bore size of the launcher, the air gap length between the armature and the drive coil, the length and width of the drive coil, and the trigger position of the armature. Change in single or multiple parameters in the launch system will influence the launch performance. The influence of single or multiple parameters on the launch performance was summarized, and the physical law as analyzed. The influence law of the EICL system parameters on the launch performance was obtained, which lays a theoretical foundation for the optimization design of EICL. Finally, experimental verification was carried out by a single-stage test platform. [ABSTRACT FROM AUTHOR]

A new approach to investigates the analytical solutions of the mathematical fractional Casson fluid model that is described by the Yang-Abdel-Cattani fractional operator having Rabotnov exponential kernel near an infinitely vertical plate. The phenomenon has been expressed in terms of partial differential equations, then transformed the governing equations in non-dimentional form. For the sake of better rheology of Casson fluid, developed a fractional model by applying the new definition of Yang-Abdel-Cattani fractional derivative operator having Rabotnov exponential kernel that describe the generalized memory effects. For seeking exact solutions in terms of Mittag-Leffler functions, for fluid velocity, concentration and temperature, Laplace integral transformation method is used to solve the fractional model. For several physical significance of various fluid parameters such as α, β, Pr, Gr, Gm, Sc on velocity, concentration and temperature distributions are demonstrated through various graphs and it is noticed that the Yang-Abdel-Cattani fractional parameter portrayed the retardation effect on momentum and energy profile, but it is visualized that for small values of Casson fluid parameter the velocity profile is higher. Furthermore, for being validated the acquired solutions, some limiting models such as ordinary Newtonian model had recovered from Yang-Abdel-Cattani fractional Casson fluid. Moreover, the graphical representations of the analytical solutions illustrated the main results of the present work. Also, in the literature, it is observed that to derived analytical results from fractional fluid models developed by the various fractional operators, is difficult and this article contributing to answer the open problem of obtaining analytical solutions the fractionalized fluid models.

The seismic performance of supplemental clutching inerter dampers (CID) for continuous span isolated bridges is assessed. The resisting force of the CID is considered nonlinear and proportional to the relative acceleration, and zero when detached. Iterative spectral analysis with the complex frequency response function under stationary earthquake excitation is used to obtain the stationary response of the isolated bridge. The iterations are required as the equivalent linear model of the CID was considered in place of nonlinear, which depends on the isolated bridge's response. The effectiveness of the CID in controlling the response of isolated bridges is studied under important system parameter variations, namely the pier time period, isolation period, isolation damping ratio, inertance ratio of the CID, and placement factor. The CID adds damping and is quite effective in controlling the response of the isolated bridges. In addition, it was also discovered that there is an optimal value of the CID inertance for which the bridge deck's root mean square absolute acceleration is at its lowest. The optimum inertance of the CID is influenced by the system parameters. The CID was also observed to effectively control the seismic response of the isolated bridges under real earthquake excitation. Finally, there was a good correlation of the response of the isolated bridges with the CID subjected to a real earthquake with that obtained under stochastic excitation. [ABSTRACT FROM AUTHOR]

Summary: Fortified rice kernels (FRK) are extruded rice‐shaped kernels manufactured by blending broken rice flour and vitamin–mineral premix. In this study, four parboiled and three raw rice with intermediate amylose content (20–24%) were processed to manufacture FRK. The system parameters (torque and die pressure), physicochemical properties (length, lightness, water absorption index and water solubility index), cooking properties (cooking time, solid loss, elongation) and textural properties of FRK were analysed and correlated using the Pearson correlation coefficient. The torque and die pressure were 16.76–22.76 Nm and 92.56–136.41 bar, respectively. Compared to raw rice, the parboiled rice showed the highest torque, die pressure and axial expansion in uncooked FRK while longer cooking times, higher elongation ratio and hardness; lesser water absorption ratio and solid loss in cooked FRK. The raw rice FRK showed higher lightness. There was a significant difference between all FRK for water absorption index (1.74–2.52) and water solubility index (2.06–3.53%). [ABSTRACT FROM AUTHOR]

A dynamic modeling method for multi-disk rod fastening rotor system with rub-impact is proposed based on the structural characteristics of gas turbine and the rub-impact fault features. The comprehensive interaction of multiple parameters on the multi-disk rod fastening rotor system is disclosed in the dynamic model, where multiple parameters include oil-film support, stator stiffness, static clearance, eccentricity, radial clearance of sliding bearing and contact effect between disks. Dynamic responses of the multi-disk rod fastening rotor system with rub-impact are derived by numerical simulation. The influence trend of system parameters on the nonlinear behaviors of the rotor system is analyzed according to time-domain, frequency spectra, whirl orbit, Poincaré map and bifurcation diagram under different system parameters. The results show that system parameters have significant influences on the nonlinear behaviors and dynamic characteristics of multi-disk rod fastening rotor system. Diversified nonlinear phenomena are presented in the rod fastening rotor system under different system parameters, such as P1 motion, P2 motion, P3 motion and quasi-periodic motion. Each nonlinear behavior of the rotor system shows regular diversities with the change of system parameters. The modeling method and numerical results contribute to the identification of dynamic characteristics and the fault diagnosis of the rotor system in gas turbine. [ABSTRACT FROM AUTHOR]

Phase noise problem in oscillators can degrade the performance of high‐speed communication systems. The author analysed the impact of phase noise problem on multi‐input–multi‐output (MIMO) systems under common and independent oscillators. The estimation of system parameters (i.e. phase noise and channel gains) is a challenging task. In this study, a data‐aided least square estimator based compressed sensing Kalman filter (KF)‐based compressed sensing (CS) scheme is proposed for tracking phase parameters. The signal model and estimation problem for the system are mathematically derived. Also, Bayesian Cramér–Rao lower bound (BCRLB) scheme is also derived. For joint estimation, the mean square error (MSE) and bit error rate (BER) performances of the BCRLBs and proposed scheme are compared. Results demonstrate that the proposed KF‐based CS scheme gives low BER values and better performance compared to other estimation schemes. The utilisation of the proposed scheme helps in reducing the MSE of the MIMO system. Finally, the proposed scheme enhances the estimation of phase noise parameters for the MIMO system. [ABSTRACT FROM AUTHOR]

In this work, a sufficiently simple model allows one to perform detailed analytic studies to gain insights for the dynamical mechanisms in the general model of gene expression. Through theoretical analysis and numerical simulation, we find that the transcription and translation delays as a bifurcation parameter can drive the system to undergo a Hopf bifurcation, thereby producing oscillation behavior. Meanwhile, the length of these delays can determine the amplitude and period of the oscillations. Moreover, an optimal rate of model parameters is also essential to induce the limit-cycle oscillations. In particular, the transcription factor concentration is called a signal that not only induces twice Hopf bifurcation, but also affects the role of the delay in the system, that is, the varying time delay leads to subcritical Hopf bifurcation and bistability under the small signal strength. On the contrary, supercritical Hopf bifurcation is generated. Furthermore, two-parameter diagram is drawn to further explore how time delay and signal strength coordinate to regulate the oscillation behavior of the system. In addition, the stability and the direction of periodic solutions bifurcating from Hopf bifurcations are determined through the explicit formulae and the global existence of periodic solutions is discussed to verify the authenticity of the simulation. These results may be helpful for us to fully grasp oscillation dynamics and provide clues for further exploring the molecular mechanism of biological rhythms. [ABSTRACT FROM AUTHOR]

It has been determined that a high percentage of medical waste could be classed as domestic waste due to the lack of segregation at hospitals. Better segregation could thus substantially decrease the amount of medical waste that is required to be treated as hazardous waste. This study aims to assess different segregation levels of domestic waste mixed with medical waste. To do so, the Stella and Vensim simulation packages were used to evaluate medical waste flows in the Thrace Region of Turkey. The most important advantage of the simulation modeling used in this study is the flexibility for adjusting parameters based on circumstances, e.g. in the case of an unforeseen event (such as the COVID-19 pandemic), the system parameters can be modified according to the situation. In this study, it is anticipated for the medical waste generation to increase from almost 2000 tons/year to 3000 tons/year in 2045 in the region, which is more than the capacity of current medical waste treatment plants. Projected waste generation flows show that it is possible to avoid 300 tons of medical waste annually by reducing the domestic content of medical waste to 50%. Precisely, for the current regional treatment capacity to be sufficient up to 2045, it will be crucial to reduce the domestic content in medical waste to 10% in the chronic care departments at regional hospitals. The importance of this further arises, as lack of meeting this need will result in an urgent requirement for installation of new units for the treatment of all the medical waste generated in the region. [ABSTRACT FROM AUTHOR]

Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The analysis was carried out in order to clarify the estimates of the expected restrictions on characteristics of new-generation mobile communications (4G, 5G) under the existing restrictions on radiated power of subscriber radio equipment, as well as in conditions where the boundaries of urban sites are outside of the area of free radio waves propagation (RWP) between subscriber and base stations. Analysis was performed using the basic principles and ensemble models of statistical theory of electromagnetic environment, as well as the basic principles of information theory that determines the radio channel capacity in presence of interference. Frequency-independent relationships have been obtained for estimating a number of system parameters of cellular communications under the conditions of multipath RWP in urban canyons and the presence of internal system interference: estimation the required equivalent isotropic radiated power (EIRP) of subscriber stations, the maximum data transmission capacity of the backward radio channel, the maximum distance of qualitative communication, and also the permissible level of internal radio interference at given requirements for communication range, and the information transfer rate of reverse radio channel taking into account the accepted restrictions on EIRP of subscriber radio equipment. The obtained relations allowus to estimate the limits of possible values of these system parameters of modern and future mobile communications; these relations also provide the opportunity to justify the quality requirements for ensuring the intra-system electromagnetic compatibility at the required data rate in backward radio channels of cellular networks and the existing restrictions on EIRP of subscriber stations.

The influence of electromagnetic induction coil launcher (EICL) system parameters on the launch performance was analyzed, and a method for measuring the launch performance of an EICL system with a muzzle velocity and energy conversion efficiency was proposed. The EICL system mainly includes a pulse power supply and launcher. The parameters of the pulse power supply mainly include the discharge voltage and the capacitance value of the capacitor bank. The structural parameters of the launcher mainly include the bore size of the launcher, the air gap length between the armature and the drive coil, the length and width of the drive coil, and the trigger position of the armature. Change in single or multiple parameters in the launch system will influence the launch performance. The influence of single or multiple parameters on the launch performance was summarized, and the physical law as analyzed. The influence law of the EICL system parameters on the launch performance was obtained, which lays a theoretical foundation for the optimization design of EICL. Finally, experimental verification was carried out by a single-stage test platform.

To investigate the effect of process parameters during high-moisture extrusion on system parameter (specific mechanical energy, SME) and product physical properties, blend of soy protein isolate, wheat gluten, and corn starch (50:40:10 w/w) was extruded using co-rotating twin screw extruder equipped with cooling die at 55 and 65% feed moisture, 150 and 170 °C barrel temperature, 150 and 200 rpm screw speed. The hardness and chewiness of products increased as all the extrusion process parameters became low. Among the tested range of process parameters in this study, a combination of high moisture (65%), high barrel temperature (170 °C), and low screw speed (150 rpm) generated the low SME input (less energy consumption) with high texturization degree of meat analogs. Layer and fibrous structure formation of the samples were influenced by variations in process parameters, primarily feed moisture and barrel temperature. [ABSTRACT FROM AUTHOR]

The discrimination power of a hyperspectral imaging system for image segmentation or object detection is determined by the illumination, the camera spatial–spectral resolution, and both the pre-processing and analysis methods used for image processing. In this study, we methodically reviewed the alternatives for each of those factors for a case study from the food industry to provide guidance in the construction and configuration of hyperspectral imaging systems in the visible near infrared range for food quality inspection. We investigated both halogen- and LED-based illuminations and considered cameras with different spatial–spectral resolution trade-offs. At the level of the data analysis, we evaluated the impact of binning, median filtering and bilateral filtering as pre- or post-processing and compared pixel-based classifiers with convolutional neural networks for a challenging application in the food industry, namely ingredient identification in a flour–seed mix. Starting from a basic configuration and by modifying the combination of system aspects we were able to increase the mean accuracy by at least 25 %. In addition, different trade-offs in performance-complexity were identified for different combinations of system parameters, allowing adaptation to diverse application requirements.

Inducible genetic switches based on tyrosine recombinase-based DNA excision are a promising platform for the regulation and control of chimeric antigen receptor (CAR) T cell activity in cancer immunotherapy. These switches exploit the increased stability of DNA excision in tyrosine recombinases through an inversion–excision circuit design. Here, the authors develop the first mechanistic mathematical model of switching dynamics in tyrosine recombinases and validate it against experimental data through both global optimisation and statistical approximation approaches. Analysis of this model provides guidelines regarding which system parameters are best suited to experimental tuning in order to establish optimal switch performance in vivo. In particular, they find that the switching response can be made significantly faster by increasing the concentration of the inducer drug 4-OHT and/or by using promoters generating higher expression levels of the FlpO recombinase.

Phase noise problem in oscillators can degrade the performance of high‐speed communication systems. The author analysed the impact of phase noise problem on multi‐input–multi‐output (MIMO) systems under common and independent oscillators. The estimation of system parameters (i.e. phase noise and channel gains) is a challenging task. In this study, a data‐aided least square estimator based compressed sensing Kalman filter (KF)‐based compressed sensing (CS) scheme is proposed for tracking phase parameters. The signal model and estimation problem for the system are mathematically derived. Also, Bayesian Cramér–Rao lower bound (BCRLB) scheme is also derived. For joint estimation, the mean square error (MSE) and bit error rate (BER) performances of the BCRLBs and proposed scheme are compared. Results demonstrate that the proposed KF‐based CS scheme gives low BER values and better performance compared to other estimation schemes. The utilisation of the proposed scheme helps in reducing the MSE of the MIMO system. Finally, the proposed scheme enhances the estimation of phase noise parameters for the MIMO system. [ABSTRACT FROM AUTHOR]

The frequency control is the mandatory task in a modern power system because of load demand variation and the integration of renewable energy sources (RESs). The main objective of automatic generation control (AGC) scheme is to maintain the balance between generation and load demand. This study proposes a graphical robust characteristic ratio assignment (RCRA) approach for PIDA controller tuning based on maximum sensitivity ($M_{\rm s}$Ms) for AGC. The basic feature of this graphical approach is that characteristic ratios ($\gamma _i$γi) in RCRA scheme are calculated in terms of $M_{\rm s}$Ms. The important part of this design is that the analytical expressions for coefficient gains of PIDA controller are derived in terms of $\gamma _i$γi and system parameters. Here, the non-reheat steam-turbine and hydro-turbine based single and multi-area power systems are considered for validation of the proposed control scheme. The critical issue in controller design for a hydro-turbine based power system is the non-minimum phase behaviour. The robustness and performance of RCRA-PIDA controller are examined under system non-linearities, parametric uncertainty and disturbances. Further, the performance of proposed approach is evaluated in the presence of RESs. Finally, it is observed that the proposed control approach performs better in comparison to the recently published control schemes. [ABSTRACT FROM AUTHOR]

In this study, a sampled‐data networked control system over a multipath routing‐enabled network is investigated, where each delivered signal in a path suffers a random delay. For such a system, the mean square stabilisation problem is considered under the joint design of the event‐driven strategy on the actuator side and the control policy on the decision‐maker side. The contributions of this study are twofold. First, by pre‐defining an application time as an event‐triggering parameter, the sampled‐data system is transformed into a stochastic form with input delay and packet dropout. When the probability distribution F(⋅) of random delay is known a priori, the close form of packet dropout rate is proposed and a set of necessary and sufficient stabilisation conditions are developed simultaneously. When F(⋅) is unknown, the reduced system is an uncertain dynamic system. Utilising matrix polynomials, a verifiable criterion is derived for stabilising the uncertain system, which is also necessary and sufficient. Second, for the scalar system, the close form of allowable sampling period bound is developed in terms of F(⋅) and system parameters. [ABSTRACT FROM AUTHOR]

• A general model of delayed p53 regulatory network in the DNA damage response is formulated. • Considering the delay as the bifurcation parameter, the local stability and Hopf bifurcation of system are discussed. • The dynamics of p53 shows digital oscillations under different initial DNA damage levels. • ATM shows a switch-like behavior and relays the DNA damage signal. • The influence of system parameters is studied by bifurcation analysis. The tumor suppressor p53 plays a central role in the DNA damage response by inducing cell cycle arrest or apoptosis and several recent experiments have shown interesting dynamics in p53 protein expression during the repair cycle. In this paper, based on the three-module model proposed by Chickermane et al., a general model of delayed p53 regulatory network in the DNA damage response is formulated by introducing ubiquitous transcription and translation delays in the p53-Mdm2 oscillator module proposed by Zhang et al.. The dynamics of p53 regulatory network in DNA damage response are investigated through analytic analysis and numerical methods. It turns out that the pulsatile behavior can be generated due to initial DNA damage signals and ATM shows a switch-like behavior and relays the DNA damage signal. Moreover, the delays required for transcription and translation in Mdm2 gene expression can drive p53 to be oscillatory and an optimal rate of model parameters is also essential to these oscillations. Furthermore, the length of these delays can determine the amplitude and period of the oscillations. These results may provide a perspective for the development of anti-cancer therapy. [ABSTRACT FROM AUTHOR]

Electric spring (ES) has been proposed to suppress the fluctuations of critical load voltage under the condition of the increasing proportion of renewable energy in the power grid, but existing popular control methods have not fully released its application potential. Therefore, a novel control strategy that enables it to operate in the entire scope is proposed in this study, which differs from the conventional methods since the fully known of all system parameters is not indispensable. Furthermore, a seamless operating mode switching method is discussed, which is important for practical application. In the end, the simulation results in PSCAD/EMTDC verify that the ES can operate stably in various regions, and can seamlessly switch between capacitive and inductive modes. [ABSTRACT FROM AUTHOR]