Connection Scheme Research Articles

How Does the “Shanghai-Shenzhen-Hong Kong Stock Connection Schemes” Impact the Excess Goodwill?

ABSTRACT Emerging capital markets are critical to global economic development and financial market stability. Therefore, with annual data of 2,701 listed firms from 2012 to 2020, the paper evaluates the effect of “Shanghai-Shenzhen-Hong Kong Stock Connection schemes” (SHSZ&HKSC) on excess goodwill with the quasi-natural experiment. The results show that the SHSZ&HKSC significantly reduces excess goodwill, where the potential paths of influence are analyst attention and foreign ownership. The in-depth analysis suggests that the reducing effect is more pronounced in firms with higher technological innovation and management quality.

About expediency of changing the connection diagram of hot water supply units

PURPOSE. The article is devoted to an urgent problem for domestic district heating. A widespread situation is considered when consumers from heat supply systems with a closed connection scheme for hot water supply plants are switched to an open heat supply system from a thermal power plant. METHODS. Study of operating modes of operating heat supply systems was performed. Data collection was carried out using an online system for monitoring and commercial accounting of energy resources. Methodology for calculation of compared mode parameters is proposed. RESULTS. Using the example of the existing heat supply system, it is shown that the effect of the measure to switch subscribers of uneconomical boiler houses to heat sources with combined heat and power generation is leveled by legislative restrictions on the development of open heat supply systems, as well as by the regulatory method for determining heat consumption in hot water supply systems. The main technical and economic indicators were selected for comparative analysis of the operation of the centralized heat supply system in conditions of complete switching of hot water supply plants according to an open circuit and in the presence of a certain number of hot water supply plants with a closed connection scheme. CONCLUSION. The period of inefficient operation of the centralized heat supply system was determined and the amount of annual economic damage was calculated, which made it possible to prove the need to bring all schemes for connecting hot water supply plants in one heat supply system to a single type.

Border-ownership tuning determines the connectivity between V4 and V1 in the macaque visual system

Cortical feedback connections are extremely numerous but the logic of connectivity between higher and lower areas remains poorly understood. Feedback from higher visual areas to primary visual cortex (V1) has been shown to enhance responses on perceptual figures compared to backgrounds, an effect known as figure-background modulation (FBM). A likely source of this feedback are border-ownership (BO) selective cells in mid-tier visual areas (e.g. V4) which represent the location of figures. We examined the connectivity between V4 cells and V1 cells using noise-correlations and micro-stimulation to estimate connectivity strength. We show that connectivity is consistent with a model in which BO-tuned V4 cells send positive feedback in the direction of their preferred figure and negative feedback in the opposite direction. This connectivity scheme can recreate patterns of FBM observed in previous studies. These results provide insights into the cortical connectivity underlying figure-background perception and establish a link between FBM and BO-tuning.

Multimodal Connectivity‐Guided Glioma Segmentation From Magnetic Resonance Images via Cascaded 3D Residual U‐Net

ABSTRACTGlioma is a type of brain tumor with a high mortality rate. Magnetic resonance imaging (MRI) is commonly used for examination, and the accurate segmentation of tumor regions from MR images is essential to computer‐aided diagnosis. However, due to the intrinsic heterogeneity of brain glioma, precise segmentation is very challenging, especially for tumor subregions. This article proposed a two‐stage cascaded method for brain tumor segmentation that considers the hierarchical structure of the target tumor subregions. The first stage aims to identify the whole tumor (WT) from the background area; and the second stage aims to achieve fine‐grained segmentation of the subregions, including enhanced tumor (ET) region and tumor core (TC) region. Both stages apply a deep neural network structure combining modified 3D U‐Net with a residual connection scheme to tumor region and subregion segmentation. Moreover, in the training phase, the 3D masks generation of subregions with potential incomplete connectivity are guided by the completely connected regions. Experiments were performed to evaluate the performance of the methods on both area and boundary accuracy. The average dice score of the WT, TC, and ET regions on BraTS 2020 dataset is 0.9168, 0.0.8992, 0.8489, and the Hausdorff distance is 6.021, 9.203, 12.171, respectively. The proposed method outperforms current works, especially in segmenting fine‐grained tumor subregions.

Experimental and numerical investigation on composite beam–column joint connection behavior using different types of connection schemes

Abstract Over the past few decades, composite joints have been regarded as one of the most promising approaches. After reviewing the research articles dealing with composite beam-column joints, it can be withdrawn that few researchers studied and developed different types of composite beam-column joints. The objectives of this paper to study the effect and behavior of different connection types on the composite beam – column joint under repeated loading as well as to investigate new forms of slab connection with column flange in composite connection joints, aiming to enhance the behaviors of the joints and make the slab endure a part of the load in a more efficient way. Five specimens with various connection types were tested to failure; the composite model number two (CM2) was considered the control specimen. Regarding the ultimate moment, the result found that CM5 has moment 50.47% more than control specimen, the lowest rotation value was in CM5. The general behaviours of the FEM were in good accordance with the experiment results. According to the parametric a higher yield strength is more rigid stiffer, the effect of web thickness on the load is too small and increase in load resistance with an increase in beam flange thickness.

Solution of the Steiner problem in the search for optimal network structure using population optimization methods

Subject of research: This paper considers an example of solving the Steiner problem for the design of utilities, in particular, power lines. Purpose of research: The study is electrical networks. The study is to assess the suitability of using genetic algorithms to find the network connection scheme with the lowest total active power losses. Methods and objects of research: Heuristic methods of population optimization are applied as a research method. Main results of research: As a result of the work, the suitability of applying genetic algorithms to solve the Steiner problem on the example of an electrical network to minimize total power losses has been evaluated.

АНАЛІЗ ХАРАКТЕРИСТИК ЛОКАЛЬНОГО НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ З'ЄДНАННЯ МЕТАЛЕВОГО КОМЛЯ З КОМПОЗИТНОЮ ЛОПАТТЮ ПОВІТРЯНОГО ГВИНТА

The article discusses the possibility of modeling the stress-strain state (SSS) of the connection of the metal butt with the composite cylindrical part of the blade using the specialized ANSYS software application and its Composite PrepPost module. Created connection models in ANSYS environment. The optimal designs for connecting the metal butt and composite material have been determined. For a simplified calculation of the connection strength, only the influence of the centrifugal force arising during operation of the screw is taken into account. In the ANSYS software package, a static load of the connection was carried out, which makes it possible to evaluate the nature of the stress distribution in the connection. A butt model and a finite element connection mesh were created. For the calculation, the characteristics of the materials of the blade elements are given. To determine a rational structural-power connection scheme, varying parameters were selected: the number of rows of spikes along the radius, the number of spike belts and the arrangement of the butt spikes. The dependence of the voltage in the composite part of the connection on the arrangement of the butt spikes was obtained. The shape and length of the spike were analyzed. The dependence of voltage on the radius of curvature of the tenon was obtained. The stress-strain state of a tenon-rounded flange is shown in ANSYS. The dependences of voltage on the length of the spike were obtained. The calculation showed that the length of the tenon L has a significant effect on the strength characteristics of the connection between the flange and the composite layer. To determine the rational position of the stud, a calculation was carried out in the ANSYS environment with a shift of all rows of studs by the amount K from the extreme position in engagement with the composite layer and a change in the linear order of the studs to a staggered one. The results of the calculation in the ANSYS environment are presented as a dependence of stress on the displacement K. A flange model is presented, where the stud arrangement is staggered, and the result of the stress calculation in the ANSYS environment. The calculation showed that changing the order of the studs from linear to staggered reduces the maximum stress to 385 MPa. The hydraulic pressure tests confirmed the calculation results. The simulation results showed a significant improvement in the mechanical performance of the joints with minimal design costs.

Improving the dynamic positioning accuracy of the electro-hydraulic drive

Research is focused on improving the dynamic accuracy of control surface positioning during the switching of hydraulic actuator modes and studying the processes and phenomena that cause control surface overshoot. Existing studies on the dynamic accuracy of hydraulic actuators have been analyzed. Transitional processes occurring in the " electromagnetic recirculation valve – electronic control unit" loop during changes in hydraulic actuator operating modes have been examined. The features of processes and physical phenomena leading to increased activation time of the hydraulic actuator have been identified. Solutions and electrical connection schemes for connecting the hydraulic actuator recirculation valve to the electronic control unit have been proposed to meet the accuracy positioning and activation time requirements. Experimental studies have been conducted to simulate the operational mode of hydraulic actuators, and failure situations modes under various load forces have been identified. Based on the results, principles for designing connection schemes for the electromagnetic recirculation valve of the hydraulic-mechanical actuator to the electronic control unit, which enhance system positioning accuracy at the structural level, have been formulated. Technical solutions aimed at achieving the specified accuracy and activation time for the hydraulic actuator have been developed and practically tested. The effectiveness and suitability of the proposed solutions for operational use, considering external factors, have been experimentally confirmed.

Optimisation of Parameters and Application of Green Recyclable Precast Hollow Steel Pipe Concrete Supports

Underground space development is a crucial approach to addressing traffic congestion in China’s cities, especially through underground construction. However, the traditional pit internal support system, particularly the concrete internal support system, has significant drawbacks. These include high energy consumption and carbon emissions, which are increasingly prominent issues. In this paper, a hollow precast concrete-filled steel tube (H-CFST) internal support system is proposed and a node connection scheme is designed. Through numerical simulation, the load-bearing characteristics of H-CFST with different aspect ratios, hollow ratios, hoop thicknesses, and hoop lengths are investigated, and the optimal design parameters are obtained. Finally, following a field application, monitoring data reveal that the precast H-CFST internal support demonstrates superior load-bearing capacity compared to the concrete internal support, successfully meeting the criteria for replacement of the concrete support.

Modular reconfigurable rotary style soft pneumatic actuators

Modular soft robots have the advantage in their ability to be reconfigured and change their morphology on-demand according to a specified task. The actuator design and particularly the inter-unit connectivity strength commonly govern the usability and functionality of these modular robots and their applications. In this paper, we present development of reconfigurable modular rotary soft actuators that allow the construction of highly versatile soft robotic actuators and systems. These pneumatically driven modular actuators are composed of an inner balloon and a flexible arched reinforcement structure to produce a rotary motion. They serve as building blocks which may be combined in various configurations to construct linear assemblies capable of extensile or bending motions. The connection scheme allows for the larger actuators to grow or shrink with the addition or removal of modules. Using finite element simulations and physical characterizations, we systematically explore the mechanical response of individual modular actuators and the role of various connection schemes on their motions upon pressurization. A key conceptual contribution of this work lies in the idea that for a modular soft robotic system, offsetting and tuning actuator alignment relative to an axis of symmetry can lead to substantial changes in mechanical performance. Utilizing these modules we demonstrate the reconfigurability of this modular system by both reconfiguring a large actuator into a pair of smaller actuators that can grasp delicate objects, and reconfiguring actuators to develop a linear crawling robot.

Distributed cooperative control for global power sharing management of interconnected microgrids in flexible multi-terminal DC connection scheme

Flexible multi-terminal direct current (MTDC) connection scheme is an ideal way to integrate multiple adjacent microgrids and form interconnected microgrids (IMGs). However, under the traditional control mode, MTDC will lead to frequency/voltage decoupling among all the microgrids. Moreover, improper control scheme design of bidirectional interlinking converters (BICs) in MTDC will make global active/reactive power sharing management impossible, which is considered as the significant task in IMGs. Therefore, a novel distributed cooperative control strategy is designed in this article. In the proposed control strategy, frequency/voltage regulations and local active/reactive power sharing management are achieved through distributed secondary control within each MG. Accurate global active/reactive power sharing management is realized by coordinating the power exchange instructions of each BIC in a distributed manner. The control dynamics of these two levels are designed to be decoupled. The stability of the proposed control strategy is demonstrated by the Lyapunov method, and its effectiveness is verified by simulating a test IMG system in MATLAB/Simulink.

Examining the determinants of Indian airlines’ revenues

The Indian aviation sector has undergone remarkable growth, driven by the emergence of low-cost carriers and diverse business models. This has resulted in a surge in passenger numbers and aircraft orders, establishing India as a vibrant global aviation market. However, this rapid expansion is accompanied by significant financial challenges, leading to distress and insolvency among numerous airlines. Despite optimistic growth forecasts, high operating costs and relatively low revenue returns pose substantial hurdles. Motivated by these challenges, this study aims to uncover the key factors influencing revenue generation in the Indian aviation industry by analysing expenditure components and their impacts on costs. The objective of this study is to address the research gap stemming from the lack of previous studies on Indian airlines that address endogeneity issues related to airline expenditures. By utilising data from 2007 to 2022 sourced from the audited annual reports of each airline, we aim to provide essential insights into the revenue dynamics of Indian airlines through the application of various econometric models including instrumental variables (IV) regression and generalised method of moments (GMM) models for improving causality and addressing endogeneity. Our findings reveal a positive correlation between unit revenue and factors such as unit expenditure, staff numbers, and passenger volume, while also highlighting the positive impacts of airline alliances and regional connectivity schemes. This research not only sheds light on industry intricacies but also underscores the imperative to address key variables to enhance the sector's sustainability and resilience in the face of ongoing challenges, offering valuable contributions to both academia and industry stakeholders for informed decision-making and strategic planning.

A Systematic Literature Review on AC Microgrids

The objective of this work is to analyze and compare AC microgrid (ACMG) solutions to introduce the topic to new researchers. The methodology used to achieve this goal is a systematic literature review using five questions: (1) How have ACMGs evolved in five years? (2) What are the standards for ACMGs? (3) What are the different schemes for connecting MGs to the utility grid? (4) What are the different control schemes in ACMGs? (5) What is an appropriate way to compare results when working with ACMGs? The articles were published in Q1/Q2 journals as based on either the Scimago Journal Rank (SJR) and/or the Journal Citation Report (JCR) between 2018 and 2022 and were from three databases: (1) Web of Science (WoS), (2) Scopus, and (3) IEEE Xplore. Publications not describing pure ACMGs, review papers, publications not related to the questions, and papers describing work that did not meet a quality assessment were excluded, resulting in 34 articles being included in this review. Results show: (1) the energy sources and AC bus nature of microgrids over five years, (2) the identification and quantification of cited standards for microgrids, (3) the pros and cons of different schemes for connecting an AC microgrid to the main grid, (4) the control schemes, classified in a hierarchical control structure, and (5) the simulation tools and experimental benches used in microgrids. Most studies considered a generic energy source and a low-voltage three-phase AC bus, 16 standards were found, and the most cited standard was IEEE Standard 1547. The most common connection scheme to the utility grid was a direct connection, most of the works proposed a modification to a hierarchical control system scheme, and the most common simulation tool was MATLAB. The preferred experimental setup consisted of parallel inverters for testing a control scheme, a prototype when proposing a power electronic system, and a laboratory microgrid for testing fault detection methods.

Simulation analysis of overvoltage caused by grounded short circuit in the collection system of far-offshore wind farms

Abstract As the distance from the shore of offshore wind farms increases, MMC-HVDC technology is gradually gaining attention in its grid connection schemes. A broadband electromagnetic transient model of offshore wind farms with a total capacity of 800 MW connected to the grid via a flexible direct current transmission system is developed. After three types of grounded short circuit faults occur at different fault positions within the power collection system, the characteristics of overvoltage are obtained and they are analyzed on the basis of considering the low voltage ride-through capability of the direct-drive permanent magnet wind power generator. Combining the two factors of range and amplitude, the results show that the overvoltage phenomenon is the most serious when a two-phase grounded short circuit occurs at the converging busbar, which can be the focus of the study when setting up overvoltage protection.

Multiple Large Shareholders and ESG Performance: Evidence from Shareholder Friction

Sustainable corporate governance increasingly influences corporate strategy considerations. Effective governance ensures organizational sustainability, with ESG being a crucial component. Large shareholders, as direct stakeholders, have a key role in developing and implementing corporate ESG strategies. Using data on Chinese listed firms over the 2011–2022 period, we find that multiple large shareholders (MLS) depress company ESG performance, suggesting that MLS may lead to friction and high coordination costs. Interestingly, stronger controlling shareholders mitigate this negative impact, particularly when they are state-owned. Our analysis shows that relatively equal power among MLS exacerbates friction, resulting in unstable executive teams and higher internal pay gaps, which lower governance (G) and social (S) scores. However, the presence of foreign and institutional investors among the large shareholders can alleviate these issues. The negative effect of MLS on ESG is significant in firms operating in clean industries, those with low analyst attention, or those not part of the “Stock Connect Scheme”. This study highlights the drawbacks of MLS in sustainable corporate governance from an ESG perspective.

A two‐stage optimization method of power supply scheme of on‐board supercapacitor‐powered tram

AbstractAiming at the power supply scheme (PSS) of the on‐board supercapacitor‐powered tram, considering the cost and margin of the PSS, a two‐stage method is designed to optimize the layout of the charging stations and the configuration of the supercapacitor (SC). First, the SC‐powered tram model and stable cycle operation model are established, and a two‐stage optimization problem model with the lowest PSS cost and the largest SC margin is established. Then, an improved dual‐population differential evolution algorithm is designed, and the layout of charging stations and the configuration of SC are co‐optimized in the first stage, and then the layout of charging stations is optimized again in the second stage. The simulation results show that co‐optimization can obtain a lower cost of PSS, and furthermore, the layout of charging stations can be optimized again to effectively improve the margin of SC, thereby improving the matching degree between the layout of charging stations and the connection scheme of SC.

Spatially resolved imaging of human macular capillaries using adaptive optics-enhanced optical coherence tomography angiography

Documenting the organization of the retinal capillaries is of importance to understand the visual consequences of vascular diseases which may differentially affect the microvascular layers. Here we detailed the spatial organization of the macular capillaries in ten healthy human subjects using a prototypic adaptive optics-enhanced optical coherence tomography angiography (AO-OCTA) system. Within the central 6° × 6°, the radial peripapillary capillaries and the superficial, intermediate and deep vascular plexuses (SVP, IVP and DVP, respectively) were consistently resolved. In 8 out of the 10 eyes, the capillary segments composing the perifoveal arcade (PFA) were perfused only by the SVP, while drainage of the PFA showed more variability, comprising a case in which the PFA was drained by the DVP. Around the center, a distinct central avascular zone could be documented for each layer in 7 of the 10 cases; in three eyes, the IVP and SVP merged tangentially around the center. In all eyes, the foveal avascular zone was larger in the DVP than in the SVP and IVP. In one eye with incomplete separation of the inner foveal layers, there was continuity of both the SVP and the IVP; a central avascular zone was only present in the DVP. The diversity of perfusion and drainage patterns supported a connectivity scheme combining parallel and serial organizations, the latter being the most commonly observed in perifoveal vessels. Our results thus help to further characterize the diversity of organization patterns of the macular capillaries and to robustly analyze the IVP, which will help to characterize early stages of microvascular diseases.

Экспериментальное определение внешних характеристик тяговых подстанций переменного тока для выбора параметров активных устройств системы тягового электроснабжения

Objective: to develop a method of experimental determination of external characteristics of alternating current traction substations for selection of parameters of active devices of traction power supply system. Methods: finding of equivalent currents of phases of a step-down transformer using the theory of linear electric circuits; statistical methods, including: construction and approximation of external characteristics of regression analysis methods, construction of theoretical and experimental law of distribution of equivalent current of traction load and determination of current quantile for a given confidence probability. Results: advantages and disadvantages of methods of simulation modeling of traction power supply system as applied to determination of parameters of active devices are shown, possibilities of experimental method are given. A detailed description of the conducted experiment is given, connection schemes of measuring devices and vector diagrams of currents and voltages are shown. The main stages of the proposed methodology for selecting the parameters of the booster transformer are outlined. Calculation formulas for determining the equivalent phase currents are presented, the external characteristic for the selected traction substation is constructed. The theoretical and experimental distribution law of the equivalent current of the traction load was constructed and the quantiles of the equivalent current were determined, which amounted to 400 A at a confidence level of 0.968. The maximum required value of volt additive for the selected traction substation and the law of volt additive voltage control for the booster transformer were determined. Practical importance: the proposed methodology of selecting the parameters of active devices of traction power supply system based on the experimental determination of external characteristics of traction substations will allow to determine more accurately the energy performance of booster transformers. It is supposed to improve the methodology by processing the results of synchronous measurements of currents and voltages at neighboring traction substations feeding the inter-substation zone. This will make it possible to expand the possibilities of application of active devices of the traction power supply system and improve the algorithms of booster transformer operation, including taking into account the operation of controlled reactive power compensation devices.

Conceptual design and model test of a pontoon-truss type offshore floating photovoltaic system with soft connection

With the growing demand for clean energy in human society, the development of offshore floating photovoltaic (FPV) systems emerged as a prominent research topic. Positive-airgap FPV systems are more practical for engineering applications, however, current designs still face challenges under open sea such as negative airgap risk and significant connecting load. To address these issues, this study presents a novel foundation and connection scheme for an offshore FPV system. First, a pontoon-truss platform was designed and its superior performance was demonstrated by comparing it to a traditional semi-submersible. Further, a four-module offshore FPV system concept was developed, in which soft ropes were first introduced as a solution for FPV module connection. After that, a basin model experiment is employed to evaluate the feasibility of proposed FPV system under wind-wave-current joint effect, where the current-wind load is simplified as a constant force, and the established numerical model is verified by experiments. To improve understanding and design, the impact of several key design parameters on dynamic responses is also discussed. The findings indicate that the airgap performance deteriorates rapidly when single module draught surpasses half of pontoon diameter, and improving soft rope stiffness is more effective and produces less disturbance to other behaviors than enhancing mooring stiffness.

Experimental study on the hysteretic performance of a self-centering frame infilled with a bamboo wall

A novel low-damage self-centering frame-bamboo wall structural system was proposed in the present study by combining a resilient self-centering frame and a bamboo scrimber wall with good deformability. Two connection schemes (A and B) between the wall and the frame were adopted. In scheme A, the wall bottom was fixed on the beam, and the out-plane displacement of the wall top was restrained. An innovative friction-slit coupled damper (FSCD) with a two-stage working mechanism was utilized for the connection between the beam and bamboo wall in scheme B, and separation between the wall and columns was adopted to avoid force transfer from the columns. A series of quasi-static tests were conducted to evaluate the seismic performance of the self-centering frame-bamboo wall structure. The results showed that the bamboo wall with connection scheme A was compressed by the adjacent columns after the gap-opening of the self-centering frame, and the strength and stiffness of the whole structure were significantly enhanced. In scheme B, the strength, stiffness and energy dissipation capacity of the structure were effectively strengthened through the adoption of the FSCD. Moreover, compared with connection scheme A, scheme B could control the force transferred to the bamboo wall at different drift ratios more reasonably, owing to the two-stage working mechanism of the FSCD. The damage degree and residual displacement of the walls could thus be controlled to meet the expected performance objectives.