Mode Of Operation Research Articles

Beyond the formal economy. Social cooperatives for labour integration under the pressure of market competitiveness

Purpose Using the theoretical framework of the substantive economy, this study aims to point out the main aspects of the substantive mode of operation that help the integration of disadvantaged people while at the same time shedding light on the barriers that hinder economically efficient functioning in a market economy. Design/methodology/approach Research focuses on Hungarian rural work integration social cooperatives, which are engaged in producing activity by the employment of disadvantaged people. In the research, mixed methods were applied: results of a questionnaire survey covering 102 cooperatives, as well as 20 semi-structured interviews and experiences from the field. A total of 17 indicators were used to explore the substantive operational features, promoting mechanisms and problems in the following areas: organisational goals and outcomes; integrating roles and functions; productive functions; and the embeddedness of cooperatives. Findings As for results, substantive operational mechanisms and tools that support the integration of disadvantaged people have been identified such as mentoring, social incentives, the ability to create local value or the expansion of local community services. At the same time, several barriers have been detected that make it difficult to operate economically, such as cooperatives being a stepping stone for workers, excessive product heterogeneity or the lack of vertically structured bridging relationships. Originality/value The value of the study is to counterpoint the mechanisms promoting social purposes of work-integration social cooperatives and the obstacles to their long-term sustainability within the framework of the substantive economy, to better understand their functioning and the less quantifiable factors of their performance.

Modeling the cortical response elicited by wrist manipulation via a nonlinear delay differential embedding.

Regarding motor processes, modeling healthy people's brains is essential to understand the brain activity in people with motor impairments. However, little research has been undertaken when external forces disturb limbs, having limited information on physiological pathways. Therefore, in this paper, a nonlinear delay differential embedding model is used to estimate the brain response elicited by externally controlled wrist movement in healthy individuals. The aim is to improve the understanding of the relationship between a controlled wrist movement and the generated cortical activity of healthy people, helping to disclose the underlying mechanisms and physiological relationships involved in the motor event. To evaluate the model, a public database from the Delft University of Technology is used, which contains electroencephalographic recordings of ten healthy subjects while wrist movement was externally provoked by a robotic system. In this work, the cortical response related to movement is identified via Independent Component Analysis and estimated based on a nonlinear delay differential embedding model. After a cross-validation analysis, the model performance reaches 90.21% ± 4.46% Variance Accounted For, and Correlation 95.14% ± 2.31%. The proposed methodology allows to select the model degree, to estimate a general predominant operation mode of the cortical response elicited by wrist movement. The obtained results revealed two facts that had not previously been reported: the movement's acceleration affects the cortical response, and a common delayed activity is shared among subjects. Going forward, identifying biomarkers related to motor tasks could aid in the evaluation of rehabilitation treatments for patients with upper limbs motor impairments.

Data-driven optimization for microgrid control under distributed energy resource variability

The integration of renewable energy resources into the smart grids improves the system resilience, provide sustainable demand-generation balance, and produces clean electricity with minimal leakage currents. However, the renewable sources are intermittent in nature. Therefore, it is necessary to develop scheduling strategy to optimise hybrid PV-wind-controllable distributed generator based Microgrids in grid-connected and stand-alone modes of operation. In this manuscript, a priority-based cost optimization function is developed to show the relative significance of one cost component over another for the optimal operation of the Microgrid. The uncertainties associated with various intermittent parameters in Microgrid have also been introduced in the proposed scheduling methodology. The objective function includes the operating cost of CDGs, the emission cost associated with CDGs, the battery cost, the cost of grid energy exchange, and the cost associated with load shedding. A penalty function is also incorporated in the cost function for violations of any constraints. Multiple scenarios are generated using Monte Carlo simulation to model uncertain parameters of Microgrid (MG). These scenarios consist of the worst as well as the best possible cases, reflecting the microgrid’s real-time operation. Furthermore, these scenarios are reduced by using a k-means clustering algorithm. The reduced procedures for uncertain parameters will be used to obtain the minimum cost of MG with the help of an optimisation algorithm. In this work, a meta-heuristic approach, grey wolf optimisation (GWO), is used to minimize the developed cost optimisation function of MG. The standard LV Microgrid CIGRE test network is used to validate the proposed methodology. Results are obtained for different cases by considering different priorities to the sub-objectives using GWO algorithm. The obtained results are compared with the results of Jaya and PSO (particle swarm optimization) algorithms to validate the efficacy of the GWO method for the proposed optimization problem.

Bias‐switchable Dual‐Mode Organic Photodetector with High Operational Stability Using Self‐trapped Cs3Cu2I5 Interfacial layer

Conventional photovoltaic (PV)‐photodetectors are hard to detect fainted signals, while photomultiplication (PM)‐capable devices indispensable for detecting weak light and are prone to degrade under strong light illumination and large bias, and it is urgent to realize highly efficient integrated detecting system with both PM and PV operation modes. In this work, one lead‐free Cs3Cu2I5 nanocrystals with self‐trapping exciton nature was introduced as interfacial layer adjacent to bulk and layer‐by‐layer heterojunction structure, and corresponding organic photodetectors with bias‐switchable dual modes are demonstrated. The fabricated device exhibits low operating bias (0 V for PV mode and 0.8 V for PM mode), high specific detectivity (~1013 Jones), fast response speed as low as 1.59 µs, large bandwidth over 0.2 MHz and long‐term operational stability last for 4 months in ambient condition. This synergy strategy also validated in different materials and device architectures, providing a convenient and scalable production process to develop highly efficient bias‐switchable multi‐functional organic optoelectrical applications.

XPENG Equity Structure Analysis and Stock Price Forecast

The market competition for new energy vehicles is becoming increasingly fierce. Under the Internet operation mode, the automobile manufacturing industry is divided into new forces and traditional automobile enterprises, which have a profound impact on the profit model of the automobile industry, and the driving force of enterprise operation is working capital. It is necessary the manage enterprise working capital to improve the comprehensive competitiveness of enterprises. Xiaopeng (also called XPENG) is a listed company of automobile brands. It adopts a dual-class share structure to allocate the company's shares. The structure can also be used to analyze how this will affect XPENG's stock price and predict the future trend of XPENG's stock price. The paper aims to analyze how this will affect the stock price of XPENG Company through the dual-class share structure, and predict the future direction of the stock price of XPENG Company. At the same time, the paper also hopes to forecast the stock price situation of XPENG Company through a series of reports and comparisons with other tram industries.

Bias-switchable Dual-Mode Organic Photodetector with High Operational Stability Using Self-trapped Cs3Cu2I5 Interfacial layer.

Conventional photovoltaic (PV)-photodetectors are hard to detect fainted signals, while photomultiplication (PM)-capable devices indispensable for detecting weak light and are prone to degrade under strong light illumination and large bias, and it is urgent to realize highly efficient integrated detecting system with both PM and PV operation modes. In this work, one lead-free Cs3Cu2I5 nanocrystals with self-trapping exciton nature was introduced as interfacial layer adjacent to bulk and layer-by-layer heterojunction structure, and corresponding organic photodetectors with bias-switchable dual modes are demonstrated. The fabricated device exhibits low operating bias (0 V for PV mode and 0.8 V for PM mode), high specific detectivity (~1013 Jones), fast response speed as low as 1.59 µs, large bandwidth over 0.2MHz and long-term operational stability last for 4 months in ambient condition. This synergy strategy also validated in different materials and device architectures, providing a convenient and scalable production process to develop highly efficient bias-switchable multi-functional organic optoelectrical applications.

An Effective Charging Torque Elimination Method for Dual-Channel Electric-Drive-Reconstructed Onboard Chargers

The idea of electric-drive-reconstructed onboard charger (EDROC) systems, along with the concept of dual-channel charging, offers a novel design, thought to enhance the integration and fault tolerance of the charging system of electric vehicles (EVs). This article investigates a dual-channel EDROC incorporating an asymmetrical six-phase permanent magnet synchronous machine (ASPMSM). A unique operation mode, called the unbalanced charging voltage operation mode, exists in this topology, in case the voltages of the two batteries are unequal. This unbalance results in different winding currents following through two channels, leading to an undesired charging torque in the machine. To ensure the safety of the system, an effective charging torque elimination method, based on dual-channel winding current balance, is proposed, which achieves a dot-shaped current path of torque generation-associated subspace (i.e., α–β subspace) by balancing the dual-channel charging power. Eventually, a controller is designed for the system and a prototype is created, to validate the effectiveness of the proposed method.

A novel model predictive controller for the drifting vehicle to track a circular trajectory

ABSTRACT In rally racing, a high sideslip cornering technique known as drifting is employed to minimise the lap time. However, for autonomous vehicles, tracking the trajectory while drifting is a challenging control problem due to the conflict between the two objectives. This paper proposes a novel model predictive controller (MPC) with two operation modes to address this conflict. In Mode 1, fuzzy expert strategies combined with the lateral error are designed to calculate the drift equilibrium point. Subsequently, the linear MPC controller is utilised to achieve quick adjustments of the lateral error. In Mode 2, terminal state constraints and error constraints are added to the MPC optimisation problem. The stability of the MPC controller is guaranteed to keep the vehicle within the expected error range. Finally, a comparison between the existing expert controller and the proposed controller is carried out on both the CarSim platform and a 1:10 scale race car. The results demonstrate that the proposed controller outperforms the existing expert controller in terms of tracking performance and drift stability.

Multi-objective capacity configuration optimization of a nuclear-renewable hybrid system

Integrating the energy storage and the base-load energy can be an efficient solution to cover the fluctuation of renewable energy. A nuclear-renewable hybrid energy system consisting of a small modular thorium molten salt reactor, solar photovoltaics, wind turbines, thermal energy storage and battery storage with two operation modes is proposed to meet the community load demand. The methodology combining multi-objective evolutionary algorithms with multi-criteria decision-making method is used to identify the optimal operation mode and gain the optimal configuration of the proposed nuclear-renewable hybrid energy system. In the first stage, the multi-objective evolutionary algorithm with better performance is utilized to gain Pareto solutions to minimize the levelized cost of energy while ensuring an acceptable level of deficiency of power supply probability. In the second stage, the multi-criteria decision-making method is adopted to select the best solution from the obtained Pareto frontiers. The optimization results demonstrate that the nondominated sorting genetic algorithm has the best performance compared with other algorithms and the operation mode with battery discharged first is more cost competitive. It is concluded from the results analysis that the selection of optimal mode is influenced by seasonal variation that contributes to large energy storage capacity requirement.

Relationship Between Coronary Artery Revascularization and Postoperative Delirium: Progress and Perspectives.

Brain dysfunction resulting from damage to the heart-brain link leads to a decline in cognitive function. This, in turn, gives rise to the clinical symptom of perioperative delirium in patients undergoing coronary artery revascularization. Those affected are provided symptomatic treatment, but many do not recover fully. Thus, medium- and long-term mortality and adverse event rates remain relatively high in patients with perioperative delirium. Despite the relatively high incidence of perioperative delirium in patients undergoing coronary artery revascularization, it has not been systematically investigated. Inflammation, vascular damage, neuronal damage, and embolism are all involved in the injury process. Here, we discuss the incidence rate, pathological mechanisms, and prognosis of delirium after coronary artery revascularization. We also discuss in detail the risk factors for delirium after coronary artery revascularization, such as anxiety, depression, mode of operation, and drug use. We hope that prevention, early diagnosis, assessment, and potential treatment can be achieved by cardiologists to improve patient prognosis.

Challenges and Recommendations for the Pension Tourism Market in the Era of Internet Plus

With the rise of "Internet Plus", the integration of the pension industry and the tourism market is facing unprecedented challenges while also presenting boundless opportunities. This study aims to explore the underlying motivations, analyze the difficulties encountered in the development of the pension tourism market, and put forward countermeasures. Moreover, the operation mode and promotion mode of the pension tourism market in the era of the "Internet Plus" are analyzed in this research through the combination of supply-demand analysis, literature review, and case analysis. The result shows that the changes in Internet technology and market demand pose challenges to the traditional pension tourism market; however, they also provide new opportunities for industry integration and market segmentation. Our research conclusion emphasizes that the industry needs to cultivate talent, introduce intelligent management, strengthen personalized services, simplify service processes, and protect information security to adapt to the changes in the Internet era so as to achieve sustainable development.

A virtual reality-based dual-mode robot teleoperation architecture

Abstract This paper proposes a virtual reality-based dual-mode teleoperation architecture to assist human operators in remotely operating robotic manipulation systems in a safe and flexible way. The architecture, implemented via a finite state machine, enables the operator to switch between two operational modes: the Approach mode, where the operator indirectly controls the robotic system by specifying its target configuration via the immersive virtual reality (VR) interface, and the Telemanip mode, where the operator directly controls the robot end-effector motion via input devices. The two independent control modes have been tested along the task of reaching a glass on a table by a sample population of 18 participants. Two working groups have been considered to distinguish users with previous experience with VR technologies from the novices. The results of the user study presented in this work show the potential of the proposed architecture in terms of usability, both physical and mental workload, and user satisfaction. Finally, a statistical analysis showed no significant differences along these three metrics between the two considered groups demonstrating ease of use of the proposed architecture by both people with and with no previous experience in VR.

All‐Optically Triggered In‐Sensor Collision Detection and Warning Based on 2D Complementary Material Devices

AbstractPrecise and timely collision detection and warning are essential to ensure the safety of autonomous driving. However, existing collision detection systems based on image sensors and radars are prone to misjudgment in adverse environments such as darkness or rain. The lobula giant movement detector (LGMD) neuron found in locusts achieves potential collision detection in unpredictable environments without the need for object recognition algorithms. Existing artificial collision detectors inspired by LGMD suffer from complex device structures and sophisticated operating modes. Here, an LGMD‐inspired all‐optically triggered in‐sensor collision detector is presented by 2D complementary material devices (2D‐CMDs) composed of n‐type molybdenum disulfide (MoS2) and p‐type platinum diselenide (PtSe2) connected in series. The proposed 2D‐CMDs couple the positive photoconductivity of MoS2 and negative photoconductivity of PtSe2 in response to looming light, successfully mimicking the antagonism of excitatory and inhibitory responses in LGMD neurons to generate a nonmonotonic escape response. The 2D‐CMDs exhibit a simple device structure and all‐optically controlled operation mode, consuming only 1 nJ of energy for each collision detection. Furthermore, in‐sensor real‐time collision warning is realized by employing a Recurrent Neural Network (RNN) to predict alarm time based on the escape response of the proposed 2D‐CMDs.

PORT INJECTION OF DIESEL, BIODIESEL, AND PETROL IN A COMPRESSION IGNITION DIRECT INJECTION DIESEL ENGINE TO MITIGATE NITROGEN OXIDES AND SOOT EMISSIONS

The internal combustion engine is critical to modern society’s development. Spark ignition engine (SI) and compression ignition engine (CI) now use gasoline and diesel as their primary fuels. As a result of burning these fuels, significant amounts of pollutants are released into the atmosphere, resulting in environmental issues. Internal combustion (IC) engines are widely acknowledged as a significant source of environmental air pollution. The engine’s fuel oxidation process not only produces useful power, but also produces significant amounts of pollutant emissions such as carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxide (NOx ), and particulate matter (PM). When developing a new combustion process, consideration must be given to: lean homogeneous air-fuel mixture, increased compression ratio, and total and instantaneous combustion, all of which result in Port Injection Compression Ignition (PICI), that is a highly efficient and clean method of combustion. The goal of this research is to conduct an experimental investigation of PICI process of compression in a Premixed Charge Compression Ignition (PCCI) mode with Pilot Injection (PI) as the combustion activator. It was found that when compared to the conventional mode, the PICI mode produces cooler exhaust gas temperatures. Temperatures were lower in the PICI mode with biodiesel and petrol as secondary and primary fuels than in the PICI mode with other fuel combinations. In the PICI mode, the HC emission decreases at higher load with all fuels. In the biodiesel conventional mode, HC emission is minimum than in other modes. For all modes of operation, the specific fuel consumption has reduced with load. Diesel and gasoline have the lowest specific fuel consumption as primary and secondary fuels, respectively. Fuel usage in the PICI mode is lower than in the normal mode.

EVALUATION OF THE ENERGY EFFICIENCY OF THE NEW CONSTRUCTIVE SOLUTION OF SUCKER-ROD PUMP

As is known, in our country, oil production is carried out both in the Caspian Sea and in oil fields on land. For the mechanized exploitation of oil fields on land, in most cases used different type of sucker-rod pumps. The main object of the study of the article is a new constructive solution of the pumping unit, the novelty of which is approved by the ownership certificates of the Eurasian Patent Organization and the Intellectual Property Organization of the Republic of Azerbaijan. The main factor characterizing the operation of pumping units is its quality indicators such as metal consumption, reliability, efficiency and energy consumption. When switching from a balanced sucker-rod pumping unit to an unbalanced the efficiency factor decreases from 0.834 to 0.65 and decreases from 0.605 to 0.312. In this case, power losses increase sharply not only in transmissions, but also in energy distribution networks. If the engine is not fully loaded or is not selected correctly, then these energy coefficients decrease even more. The selection of engine power is performed according to the worst conditions, i.e. the cyclic mode of operation of an unbalanced pumping unit. Despite this, it can be said that in almost all oil fields, the power of asynchronous motors is greatly exaggerated, which causes additional losses. In article proposed expressions for determining the optimal power of the electric motor were proposed, taking into account the efficiency factor of the balancing device during the balancing of the proposed new constructive solution of the beamless pumping unit with a combined, movable counter weights and rotary counter weights. This allows to prevent excess energy consumption and reduce energy costs. Which is very important in the era of globalization, when energy prices are rising sharply.

Electrostatically Induced Black Phosphorus Infrared Photodiodes

AbstractHomojunctions are key elements in many mainstream electronic devices. However, conventional dopant‐based “pn” homojunctions are not easily achievable in new material families, such as the 2D materials. Several recent 2D material studies have shown that lateral pn homojunctions can instead be electrostatically induced using back gates localized to either the source or drain contacts. Here, a hBN‐encapsulated black phosphorus dual‐gate device containing a lateral pn homojunction, whose orientation can be switched via application of back gate voltages, is demonstrated. Importantly, this study extends the state‐of‐the‐art for this architecture by characterizing the photoresponse under infrared (λ = 2.2 µm) illumination. It is shown that when biased to form a homojunction, the device exhibits the photovoltaic effect, resulting in a specific detectivity of 8.5 × 108 cm Hz1/2 W−1 at 77 K under short‐circuit conditions, and an open circuit photovoltage up to 175 mV at 77 K. Further, it is shown that the device can be operated in photoconductive mode, allowing a high responsivity of 0.55 A W−1. This device is thus highly reconfigurable as it can be switched between photovoltaic and photoconductive modes of operation to prioritize low noise and fast response or high responsivity.

Increasing the efficiency of the automotive generator due to active rectification

Problem. Increasing fuel economy requirements for modern vehicles lead to an increase in their electrification. The rise in the number of electrical systems leads to a higher load on the electrical power supply system, with the vehicle's power load reaching 2-3 kW. Leading automobile companies have begun serial production of vehicles with the new 12/48 V power supply voltage standard. The traditional alternator used today is a synchronous alternator, and rectifier diodes are used to convert the generated AC to DC to charge the battery, which is inefficient. A study of losses in an automobile alternator shows that the diode rectifier creates a significant portion of the machine's losses at low speeds, resulting in increased fuel consumption. The solution to this problem is to use a synchronous rectifier to replace traditional rectifier diodes, thus improving the efficiency of the AC/DC rectifier. Goal: To improve the economic and environmental characteristics of a mild hybrid vehicle through the use of a synchronous two-semi-periodic rectifier with a midpoint in the car generator. Methodology: Analytical methods are used to calculate energy losses on diodes and in the phase windings of the generator when employing a two-semiperiod rectifier with a midpoint, compared to a bridge rectifier. Results: The structure, functions, and operation modes of the synchronous rectification system are considered. The effect of synchronous rectification on the generator efficiency of a mild hybrid vehicle is analyzed. It was determined which configurations of synchronous rectification are more effective from the standpoint of energy saving and under which operating conditions. It was determined that in a two-semiperiod rectifier with a midpoint, compared to a bridge rectifier, there will be the same heating of the phase windings and 2 times fewer losses on the diodes. Practical value: A version of the bridge synchronous rectification system of the 48 V generator for a mild hybrid vehicle using MOSFET transistors and specialized control IC is proposed. A synchronous rectification system and its circuit implementation for a 12 V generator based on a two-semi-periodic rectifier scheme with a midpoint is proposed, which allows increasing the energy efficiency and economy of the automobile generator.

A bidirectional resonant CLLC converter combining three‐level characteristic and bipolar DC structure

SummaryIn order to meet the efficient and convenient usage requirements for bidirectional DC‐DC converters in some fields such as DC microgrids and vehicle power conversion systems, a bidirectional resonant CLLC converter combining three‐level characteristic and bipolar DC structure is used and analyzed in this paper. A three‐level topology is adopted in the resonant CLLC converter, which can achieve stable and wider range voltage regulation through the frequency adjustment combined with duty cycle and phase shift modulation, and can also increase the flexibility of control strategy. The application of bipolar DC structure enables this resonant CLLC converter to have multi‐port on one side, and the method of using two interleaved inductors combined with synchronous rectification enables the output voltage of the converter to maintain a certain balance. In this paper, the voltage gains and running states of the three‐level regulation method are analyzed, and then these operation modes and the bipolar DC voltage balance effect of the converter under synchronous rectification control are verified by the experiment results.

A novel mathematical optimization method to obtain the maximum-power electrical configuration of thermoelectric generators for energy harvesting

Waste thermal energy recovery with thermoelectric generators has been widely studied as a method to make systems that produce hot exhaust gases, such as aircrafts, ground vehicles and factories, more sustainable. In this type of applications, the mismatch in hot and cold side temperatures of thermoelectric modules (TEMs) creates a mismatch in the electrical output. For each situation, there is a certain electrical interconnection between the modules that gives the maximum global power output. Three optimization models to find what is the best way of connecting the TEMs without a trial-and-error process, as usually done in previous literature, based on mathematical programming are proposed: single branch of series-connected TEMs, multiple parallel-connected branches of series-connected TEMs, and multiple groups of independent series-connected TEMs. The main novel contributions of this paper are: (i) a mathematical optimization approach that provides how to connect the thermoelectric modules one by one, (ii) the application of the above-mentioned method in a common case study: an automotive thermoelectric generator, (iii) information about how the optimal connection between modules changes if the heat source changes its operation (iv) a method for selecting a fixed optimal connection even when the heat source operation changes, e.g. different operation modes in a thermal engine, based on introducing weighting parameters in the optimization mathematical model. The optimization approach followed here is novel and has not been applied before to thermoelectric generators.

Development of the Bipolar Junction Transistor Diagnostic Test (BJTDT) to explore the second-year undergraduate Myanmar electronic and Thai electrical engineering students’ understanding of BJT working principles and applications

ABSTRACT A bipolar junction transistor (BJT) and its operation are fundamental concepts for the understanding of power electronics (industrial electronics), transistor-transistor logic (TTL), electronic switching, and signal amplification in modern electronics. Previous research showed that non-major engineering, computer, electronic, and electrical engineering students could not understand the basic concepts involved in a BJT. This paper describes the development of a two-tier diagnostic test, the test’s administration, limitations, the participants’ detailed context, and findings from a study that explores Myanmar and Thai second-year undergraduate students’ understanding of BJT working principles and applications. The results revealed that many students in both countries had the same alternative conceptions about collector current in each operation mode of the BJT. Some alternative conceptions differ from the previous research, such as a) the collector current does not depend on the base current in cut-off mode, and b) changing the collector current does not depend on the base current in active mode, but it depends on the collector supply voltage. These research findings provide valuable information and instruments for teachers to insight, prevent, and correct the alternative conceptions proposed by students.