Two-stage Control Research Articles

Drivers of green innovation and green acquisition: empirical evidence from the food and beverage industry

Purpose Green innovation and green acquisition are key green marketing strategies. This paper aims to explore and compare the drivers of green acquisition and green innovation strategies firms adopt. Moreover, the moderating role of top management team (TMT) sustainability commitment is investigated. Design/methodology/approach The research model used secondary data based on 1,565 firm-year observations in the beverage and food industry in the US. The two-stage control function approach was used for data analysis. Findings Media attention motivates firms to pursue both green innovation and green acquisition. The TMT sustainability commitment plays a pivotal moderating role. It strengthens the link between environmental regulation stringency and green innovation but weakens the impact of media attention on green acquisition. Practical implications Managers can leverage the study’s findings to guide sustainable marketing decisions in response to environmental regulations and media scrutiny. Policymakers and investors can encourage firms to adopt more sustainable practices, helping align corporate strategies with Sustainable Development Goals 9 and 12. Originality/value Though green innovation determinants are extensively studied, most studies rely on surveys or qualitative methods rather than secondary data. Also, as an alternative to developing in-house green technologies or products, the drivers of green acquisition remain unclear despite its growing prevalence. This study addresses both gaps in the sustainable marketing literature.

Research on robust fault-tolerant cooperative control for multi-stage satellites

Abstract The ultra-agile, ultra-stable, and ultra-pointing platform (ASP) is introduced on the basis of the satellite platform by using two-stage control to realize stable control and agile ability of the payload. In order to improve the reliability and attitude control capability of multi-stage satellites with a two-dimensional scanning motion mechanism, a robust fault-tolerant cooperative control algorithm for multi-stage satellites is proposed in this paper when the actuators of the ASP are faulty. Firstly, a dynamic model of a multi-stage satellite and typical fault models of actuators are established. The impact of faults on the multi-stage system is also analyzed in this paper. Secondly, a sliding mode fault observer is proposed for multi-stage satellites aiming at solving the problem of actuator failure. An adaptive sliding mode fault-tolerant control algorithm is designed, and the switch function is also improved which is chattering-free. The stability of the proposed controller is proved by using the Lyapunov stability principle. Finally, the effectiveness of the proposed control algorithm is verified through numerical simulations, and the comparison between four other fault-tolerant control algorithms demonstrates the superiority of the algorithm proposed in this paper.

How promotion mix helps sustain brand sales during market transitions: insights from the pharmaceutical industry

Purpose Pharmaceutical marketers use detailing, sampling and direct-to-consumer advertising (DTCA) to promote a branded prescription drug (brand drug) to health-care professionals and consumers. These promotion mix elements help raise brand awareness, increase prescription likelihood and guard a product market against competing brand drugs. However, the extent to which these elements remain effective when a brand drug goes off patent and its marketing exclusivity expires, allowing low-price generics to enter the market, remains unclear. This study aims to explore the effectiveness of promotion mix elements before and after the market entry of a generic drug. Design/methodology/approach The authors collected and analyzed a panel data set of 41 brand drugs from 7 therapeutic classes between 2007 and 2014 (3,201 observations) using the two-stage control function approach to address potential endogeneity. Findings The effectiveness of promotion mix elements changes significantly, but not in a universally uniform way, during a market transition. Detailing and DTCA are increasingly effective after a brand drug’s generics enter the market. In contrast, sampling is more effective before the market transition. The positive effects of sampling on brand sales are stronger when the price of a brand drug is higher than the average price of its competing brands. Sampling also helps amplify the positive influences of detailing and DTCA on brand sales. Research limitations/implications This study shows that pharmaceutical promotion is not equally effective in the brand drug market with/without generic competitors. Detailing and DTCA are increasingly effective when generic competition intensifies. In contrast, the distribution of free drug samples is less effective after more generic drugs enter the market. Practical implications Incumbent brands’ promotion expenditures often drop dramatically when the expiration of their patents is near, a practice that likely continues after generics enter the market. Taking into consideration these industry norms and their findings, the authors suggest that promotional decisions during a market transition should not overly focus on cutting promotional expenditures across the board. Since a firm’s promotional expenditure tends to be expensive, factoring in information on the effectiveness of each promotion mix element helps marketers make well-informed strategic decisions on resource allocation during the transition from a market without generics to a market with generics. Originality/value Previous studies do not explicitly account for structural changes in the brand drug market over time. However, the expiration of patent and marketing exclusivity marks a transitional period in which a brand drug eventually competes with its generic counterparts. Given the criticality of such structural change, the authors examine brand drugs’ promotion effectiveness in the presence of their generic counterparts.

Two-stage control model based on enhanced elephant clan optimization for path planning of unmanned combat aerial vehicle

Two-stage control model based on enhanced elephant clan optimization for path planning of unmanned combat aerial vehicle

Design and optimization of two-stage controller for three-phase multi-converter/multi-machine electric vehicle

Abstract Electric vehicles (EVs) cut greenhouse gas emissions and our use of non-renewable resources, making them more attractive. EVs have lower fuel and maintenance expenses than internal combustion engine automobiles. This study proposes a multi-converter/Multi‒Machine system with two induction motors (IM) that drive a pure EV’s rear wheels. EV two-stage controllers using a simple Adaline neural network (NN) regulate Field-Oriented regulate of a three-phase IM. To control IM speed, the first controller level is a hybrid proportional–integral (PI) with a robust integral sign of error (RISE) controller. Injection torque is controlled by PI‒adaline NN in the second controller step. The simple Adaline NN improves two-stage controller performance. The Multi-Verse Optimization algorithm found the ideal RISE parameter to improve EV drive system performance. A plug-in EV’s linear speed is controlled by the Electronic Differential Controller (EDC). It uses the driver’s reference speed and steering angle to set each driving wheel’s reference speed. EDC adjusts wheel speeds to enhance traction and stability during cornering, accelerating, and decelerating. Utilizing this information, the EDC can effectively distribute power and torque to the wheels, thereby enhancing vehicle handling and overall performance. Three distinct road scenarios and the designated driving route topology have been used to act and demonstrate the resistive forces that affected the EV while it was traveling down the road. By using Matlab (Simulink), EV’s roadworthiness and efficiency will be evaluated.

Two-stage auxiliary drifting path tracking control for distributed driving three-axle commercial vehicles

When maneuvering corners at high speeds, commercial vehicles experience significant sideslip angles and tire force saturation, which can lead to severe traffic accidents. Incorporating intelligent driving technology to develop a controllable scheme that surpasses stability constraints and maintains the vehicle in a drift state is crucial for enhancing driving safety. Therefore, based on the model characteristics of distributed drive three-axle(DDTA) commercial vehicles, a two-stage auxiliary drift controller is proposed. In the auxiliary drift stage, time-varying model predictive control (MPC) is employed to track the desired states and achieve steady-state drift path tracking under extreme working conditions. A two-stage controller switching strategy is implemented based on road information. In the yaw stability control stage, an advanced auxiliary system facilitates cooperative control to smoothly restore tire attachment and vehicle yaw. Simulation results demonstrate that the control strategy ensures consistent path tracking performance even when adhesion of the middle and rear axle saturates and peak vehicle sideslip angle reaches 32.09°. After completing the drifting, vehicle yaw successfully returns to a stable state. Subsequently, miniaturized vehicle tests qualitatively analyze relevant conclusions by elucidating transient instability evolution in vehicles subjected to steering and distributed drive. The controllable stability boundary of the vehicle is thus expanded, thereby enhancing the engineering feasibility of drift technology.

Two-Stage Control Strategy Based on Motion Planning for Planar Prismatic–Rotational Underactuated Robot

Two-Stage Control Strategy Based on Motion Planning for Planar Prismatic–Rotational Underactuated Robot

Machine learning-based active control for lightweight antenna with force density method and nested genetic algorithm

This work proposes the integration of a tensegrity structure composed of struts and cables into an antenna, thus achieving a lightweight and optimized design for the large-scale system. Active control is introduced to ensure the deformation accuracy of the cable-strut antenna, while a shape sensing method based on force density information is adopted to obtain the deformation field of actual wind cases from monitoring the cable forces. Numerical simulations are performed to verify the accuracy of the method, and a multi-objective optimization framework is employed to determine the optimal positions and control of actuators for active control. A machine learning-based framework is proposed to achieve rapid response of the active control system under actual wind cases. The framework is composed of a two-stage control system that combines the shape sensing method with the multi-objective optimization approach. The machine learning framework establishes a quick response system that monitors changes in the cable forces, thus ensuring structural accuracy control under wind load without structural analysis.

Nonlinear Two-Stage Control Scheme Design for All-Aspect Guidance

Nonlinear Two-Stage Control Scheme Design for All-Aspect Guidance

Hierarchical control combined with higher order sliding mode control for integrating wind/tidal/battery/hydrogen powered DC offshore microgrid

Due to the intermittent nature of renewable energy sources, energy storage devices play a key role in achieving power balance for microgrid. To reduce the overall carbon footprint, this paper considers fuel cells and batteries as auxiliary sources with wind and tidal energy as primary sources. A two-stage control system has been designed, which has been subdivided into system-level and local-level control systems. The system-level control includes an energy management system that optimizes load distribution, minimizes system cost, and meets battery state of charge and hydrogen level constraints. To make the microgrid independent and minimize transportation costs, on-site hydrogen production has been deployed using an electrolyzer system. At the local level, a fast reaching law-based terminal sliding mode controller has been implemented for accurate and robust tracking of the references provided by the system-level control. The stability of the proposed framework has been validated using the Lyapunov stability criteria. The proposed 600 V and 400 kW microgrid structure has been realized using MATLAB/Simulink simulations. Furthermore, the effectiveness of the proposed control scheme has been compared with PID and ITSMC in terms of accuracy and robustness under both power deficit and surplus modes. Finally, the real-life efficacy has been validated by utilizing controller hardware-in-loop experiments.

Online Active Fault Detection for Over-Actuated Systems With Prescribed Control Performance

In the field of fault detection, active fault detection for dynamic systems is an emerging research topic. By redesigning the control input, active fault detection can enhance fault detection performance. In this study, the online active fault detection problem is investigated for over-actuated systems, where the control input is designed by considering both the prescribed control performance and the fault detection performance. A two-stage input design architecture is constructed, where the first stage is a virtual controller design and the second stage is a control allocation design. In the first stage, the virtual control input is designed by utilizing a prescribed performance function to fulfill the control requirement. In the second stage, a differential evolution method is adopted to obtain an optimal control allocation algorithm for improving the fault detection performance. The designed control input can both improve fault detection performance and achieve the prescribed control performance. Two cases, including a numerical example and a manned submersible propulsion system, are studied to support theoretical results. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —In this study, the aim is to design a control input for over-actuated systems to obtain better fault detection performance while achieving prescribed control performance. To achieve it, a two-stage control input design architecture is constructed, where the first stage is a virtual controller design and the second stage is a control allocation design. In the first stage, choose a proper prescribed performance function and a sliding mode function to accomplish the transient and steady behavioral bounds on the tracking errors. In the second stage, design a special observer to generate the system residual signal, which is used for indicating system faults. Based on the residual signal, construct an index for the control allocation algorithm. Differential evolution algorithm is applied to obtain the optimal control allocation algorithm by maximizing the index. Thus the control allocation algorithm which can improve fault detection performance is designed. In this way, the input can improve fault detection performance without affecting system behavior. The proposed technique of this study can be applied to dynamic systems with input redundancy.

Cascade Control of Grid-Connected NPC Converters via Sliding Mode Technique

This paper proposes a two-stage control strategy including an adaptive sliding mode control (ASMC) and a nonlinear high-gain observer (HGO) for the three-level neutral-point-clamped (NPC) converter in dc microgrids. In the outer loop, an ASMC is utilized to regulate the dc-link voltage. By introducing an adapted gain, the tradeoff between the chattering and dynamic performance of the classic sliding mode control is overcome, thus the transient response of the NPC converter can be further enhanced without increasing the chattering. In addition, a nonlinear HGO is cooperated with the ASMC method to reject exogenous disturbance for the NPC converter, which not only assures a high disturbance rejection capacity but also accommodates the inevitable measurement noise in the actual applications. For the inner loop, in consideration of the parameter uncertainty, a high-gain observer-based second-order sliding mode (SOSM) control is adopted to assure the steady state performance and the robustness of the NPC converter. Finally, a set of comparative experimental results confirm the effectiveness and superiority of the proposed control scheme implemented in the NPC converter. Additionally, the robustness under parameter variation of the proposed method is also validated.

A Two-Stage Optimal Preventive Control Model Incorporating Transient Stability Constraints in the Presence of Multi-Resource Uncertainties

The volatility and uncertainty introduced by increasingly integrated renewable energy pose challenges to the reliable and stable operation of the power system. To mitigate the operation risks, a two-stage optimal preventive control model that incorporates transient stability constraints and considers uncertainties from multiple resources is proposed. First, the uncertainties of different re-sources are modeled, with which the non-sequential Monte Carlo sampling method is used to correspondingly generate the scenarios. Thereafter, a two-stage control model that balances operational safety and economy and realizes preventive control and emergency control is built. The operation schedule from the preventive control stage aims to minimize the transient stability probability and operation costs. If any faults destabilize the system, the emergency control stage will be activated immediately to help the system recover stability with minimal control costs. To expedite the solving of the two-stage model, a multi-objective particle swarm algorithm based on entropy-TOPSIS is proposed. Finally, the effectiveness of the proposed model and solving algorithm are validated with the modified IEEE118 node system.

A new two-stage controller design for frequency regulation of low-inertia power system with virtual synchronous generator

A new two-stage controller design for frequency regulation of low-inertia power system with virtual synchronous generator

Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier

While an ideal Doherty power amplifier has a linear response, the load modulated balanced amplifier (LMBA) has a compressive response under ideal conditions. This inherent nonlinear characteristic is due to the lower power contribution of the single auxiliary device as the balanced amplifier transistors approach compression. This article presents an LMBA with a two-stage control signal amplifier in place of the single auxiliary device. The idea is to preserve a high and constant gain across the high- and low-power regions by tuning the two-stage gain control signal to match the balanced amplifier gain. An optimal load trajectory can be found for a high-efficiency design by appropriately terminating the second harmonic while ensuring an optimal impedance match in all devices. At the same time, by setting an optimal output power from the auxiliary device, sufficient power is provided to linearize the response of the main power amplifier beyond the output back-off power boundary. As proof of concept, a prototype is designed and implemented. The experimental measurements demonstrate a drain efficiency of 59%–64% at maximum output power and 46%–52% at 7.5 dB output back-off power over the target frequency range of 3.3–3.8 GHz.

Research on Optimal Voltage Control of Distribution Network with the Participation of EVs and PVs

With the accelerating penetration of photovoltaics (PVs) and electric vehicles (EVs), distribution networks face the risks of voltage violations and fluctuations. On the one hand, conventional voltage regulation resources like OLTC transformers and capacitor banks feature slow response and limited lifetime duration, making them incapable of quickly responding to the temporary voltage issues created by PVs and EVs. On the other hand, EVs and PVs interact with the power grid via fully controllable power electronic converters capable of real-time adjusting their operating settings, making them ideal voltage support resources. To exploit the voltage support capability of PVs and EVs, this paper proposes a two-stage control scheme for the voltage regulation of distribution networks, consisting of the day-ahead and intraday control stages. The day-ahead control mitigates potential voltage violations via day-ahead scheduling of the operation settings for OLTC transformers and capacitor banks. The intraday control further alleviates voltage deviations and voltage fluctuations based on the reactive power support of PV systems and the rational EV charging/discharging scheduling. A rolling optimization-based control technique is proposed in the intraday control stage to achieve real-time control of EVs and PVs with the stochastic nature of EV charging behaviors inherently considered. The proposed two-stage voltage regulation scheme is validated via case studies performed on the IEEE 123-node test feeder integrated with PVs and EVs.

People learn a two-stage control for faster locomotor interception

People can use the constant target-heading (CTH) strategy or the constant bearing (CB) strategy to guide their locomotor interception. But it is still unclear whether people can learn new interception behavior. Here, we investigated how people learn to adjust their steering to intercept targets faster. Participants steered a car to intercept a moving target in a virtual environment similar to a natural open field. Their baseline interceptions were better accounted for by the CTH strategy. After five learning sessions across multiple days, in which participants received feedback about their interception durations, they adopted a two-stage control: a quick initial burst of turning accompanied by an increase of the target-heading angle during early interception was followed by significantly less turning with small changes in target-heading angle during late interception. The target’s bearing angle did not only show this two-stage pattern but also changed comparatively little during late interception, leaving it unclear which strategy participants had adopted. In a following test session, the two-stage pattern of participants’ turning adjustment and the target-heading angle transferred to new target conditions and a new environment without visual information about an allocentric reference frame, which should preclude participants from using the CB strategy. Indeed, the pattern of the target’s bearing angle did not transfer to all the new conditions. These results suggest that participants learned a two-stage control for faster interception: they learned to quickly increase the target-heading angle during early interception and subsequently follow the CTH strategy during late interception.

The investigation of a unbalanced barrel pitching system’s characteristics degradation and compensation under gradual erosion behavior

The unbalanced barrel pitching system is a typical electro-hydraulic coupling servo control system, the performance of which determines the response speed and hit probability of vehicle mounted weapon equipment. However, in the actual service process, its core component, the high precision jet pipe servo valve, will produce the gradual erosion of the pilot stage’s receivers and the power stage’s throttling edges, which will induce the performance degradation of the unbalanced barrel pitching system, and finally greatly reduce the performance of barrel weapons. Therefore, a pressure and position double loop state space model of unbalanced barrel pitching system including the core parameters of performance degradation is established. The erosion behavior mechanism model of jet pipe servo valve is constructed, and the performance degradation characteristics of the unbalanced barrel pitching control system under the condition of erosion are further analyzed. Finally, aiming at the double loop structure of internal pressure loop and external position loop, the RBF Network Adaptive Robust Sliding Mode-Proportional Integral Derivative two-stage controller of barrel system is designed, based on which the experimental platform of unbalanced barrel pitching control is built. The experimental results are in good agreement with the theoretical results, so the proposed control method can effectively suppress the degradation of internal structural parameters induced by erosion, that is, it can better compensate the performance degradation of barrel pitching system induced by gradual erosion behavior.

Two-stage control algorithm for magnetic fluid deformation mirror with dual-layer actuators

To increase the correction effectiveness of full-order aberration, a control system based on a magnetic fluid flexible mirror with dual-layer actuators is presented. The combined magnetic field created by the Maxwell coil and the double-layer driving coils controls the geometry of the magnetic fluid surface. A model-based optical sensorless control approach for lower layer coils is developed and aimed to enable high magnitude restoration of lower-order aberrations. An adaptive important factor that causes on Youla parameterization, on the other hand, is developed for the upper coils to rectify higher-order residual aberrations. Matlab is used to simulate the algorithm in order to test its performance in full-order aberration correction, and the results reveal that the approach has good correction performance.

MP72-01 A RANDOMIZED CONTROLLED TRIAL (RCT) OF ONE-STAGE OR A NOVEL TWO-STAGE CONSENT IN MEN OFFERED A BRIEF MIND-BODY INTERVENTION DURING PROSTATE BIOPSY

You have accessJournal of UrologyCME1 Apr 2023MP72-01 A RANDOMIZED CONTROLLED TRIAL (RCT) OF ONE-STAGE OR A NOVEL TWO-STAGE CONSENT IN MEN OFFERED A BRIEF MIND-BODY INTERVENTION DURING PROSTATE BIOPSY Christopher Gaffney, Emily Vertosick, Behfar Ehdaie, and Andrew Vickers Christopher GaffneyChristopher Gaffney More articles by this author , Emily VertosickEmily Vertosick More articles by this author , Behfar EhdaieBehfar Ehdaie More articles by this author , and Andrew VickersAndrew Vickers More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003340.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Poor trial accrual caused by cumbersome informed consent procedures delays advancements in clinical medicine. Two-stage consents may improve patients’ informed consent experience by avoiding information overload, prioritizing patient treatment autonomy, and eliminating placebo regret. We tested the feasibility of enrollment and patient reported outcomes for two-stage consent in a “low stakes” RCT of a brief mind-body intervention during prostate biopsy (mindful biopsy). METHODS: We performed a RCT of one stage (standard) or two stage (an initial consent indicating willingness to be approached for a randomized prostate biopsy intervention followed by a second consent for patients randomized to the intervention) consent as part of a RCT of mindful biopsy versus usual care (NCT03507725). We compared patient reported Quality of Informed Consent (QuIC), State-Trait Anxiety Inventory (STAI), Decision Conflict Scale (DCS), Consent Related Anxiety (CRA), and the Decisional Regret Scale (DRS) between groups. Differences in means and dichotomous variables were calculated using two-sample t-tests and Fischer’s exact tests, respectively. RESULTS: Among 125 enrolled, 64/66 patients randomized to one-stage consent and 58/59 randomized to two-stage participated. 29/58 patients in the two-stage consent arm were randomized to treatment. There was no statistically significant difference in the QuIC and the 95% CI excludes any clinically relevant difference between patient understanding of one-stage and two-stage consent. Furthermore, STAI, DCS, CRA, and DRS and were similar between one and two-stage consent (Table). Although second stage consent was often conducted on the day of biopsy, CRA scores were similar between two-stage treatment and one-stage consents (1.3 and 1.3) and there was a signal toward improved anxiety in the two-stage control group (0.3). CONCLUSIONS: Robust patient enrollment in “low stakes” clinical trials is feasible using two-stage consent and maintains patient understanding of consent. Though unanticipated for this “low stakes” trial, we saw some evidence of lower anxiety from two-stage consent. Future studies should evaluate two-stage consent in trials with higher stakes. Source of Funding: PCORI © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1024 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Christopher Gaffney More articles by this author Emily Vertosick More articles by this author Behfar Ehdaie More articles by this author Andrew Vickers More articles by this author Expand All Advertisement PDF downloadLoading ...