Reduction In Dissipation Research Articles

A novel high-Q Lamé mode bulk acoustic resonator

This study introduces a novel high-Q Lamé mode MEMS resonator, optimized through support beam structures and etching hole distributions to minimize anchor losses and thermal elastic dissipation (TED). Fabricated using a Silicon-On-Insulator (SOI) process, the resonators achieved Q values of 129,200 and 102,100 in different designs, demonstrating significant improvements in vacuum conditions and highlighting air damping as a key loss mechanism. Nonlinear analysis revealed material nonlinearity dominance. These findings offer valuable guidelines for developing high-end MEMS devices, such as low phase noise oscillators and high-resolution sensors, by showcasing substantial reductions in energy dissipation and enhanced Q factors through structural optimizations.

Experimental and Numerical Investigation of Cold Joint Effects on Intermediate Concrete Moment Frame Under Cyclic Loading

This study investigates the seismic behavior of reinforced concrete flexural frames with a focus on the impact of cold joints (CJs). Three one-bay concrete frames, scaled to 2:3 according to ACI 318-19(22), were tested under axial and cyclic loading. The frames included a control frame without CJs, a frame with CJs, and a frame with CJs reinforced with fiber-reinforced polymer (FRP) sheets. Initially, the difference between the frame without CJs and the frame with CJs was examined, revealing a 10% reduction in cumulative energy dissipation, a 24% reduction in ductility, and an 18% reduction in lateral load capacity for the frame with CJs. Additionally, the stiffness in frames with CJs has decreased. Subsequently, the frame with CJs was reinforced with FRP sheets, leading to a 33% increase in cumulative energy dissipation and a 54% increase in lateral load capacity. However, the FRP sheets, while increasing load capacity, introduced brittleness, which reduced ductility. Crack patterns varied, with the frame without CJs showing vertical cracks near connections at 3% drifts, and the frame with CJs exhibiting tension and compression vertical cracks at 1% drifts. After validating the numerical models, two structural designs have been proposed to mitigate the negative effects of CJs in reinforced concrete structures. These designs are intended to improve seismic performance and enhance the structure's resistance to cyclic loads.

Bending Performance of Reinforced Concrete Beams with Rubber as Form of Fiber from Waste Tires

An investigation was conducted to assess the efficacy of using waste rubber as a substitute for a portion of an aggregate to enhance concrete’s sustainability. For the purpose of accomplishing this objective, a total of 12 specimens were constructed and then subjected to a series of tests to investigate their bending behavior. The samples were constructed with the following dimensions: 1000 mm length and a 100 mm by 150 mm cross-sectional area. A few factors were selected, including the impacts of the longitudinal reinforcement ratio and the waste rubber ratio. Based on the volume of aggregates, rubber replacement rates of 0%, 5%, 10%, and 15% were investigated in this study. To assess the beam bending behavior, the stirrup width and spacing were kept constant at ∅6/10. The longitudinal reinforcement was composed of three diameters: ∅6 at the top (for all beams) and ∅8, ∅10, and ∅12 at the bottom. The experimental results demonstrated that the effects of varying amounts of waste rubber and tension reinforcement on the bending and cracking of reinforced concrete beams (RCBs) were varied. The findings indicate that the incorporation of waste rubber into concrete results in a reduction in both the load-carrying capacity and the level of deformation of the material. Additionally, it was shown that as the amount of waste rubber in the RCB increased, the energy absorption capacity and ultimate load decreased. There was a reduction in energy dissipation of 53.71%, 51.69%, and 40.55% for ∅8 when longitudinal reinforcement was applied at 5%, 10%, and 15% replacement, respectively. Additionally, there were reductions of 25.35%, 9.31%, and 58.15% for ∅10, and 38.69%, 57.79%, and 62.44% for ∅12, respectively.

Optimizing steel plate shear wall performance: influence of infill plate thickness and connection length to vertical boundary elements

The Steel Plate Shear Wall (SPSW) is widely used as a lateral force resisting system in areas prone to high seismic activity. This is because of its exceptional ductility and ability to dissipate energy. Previous studies have indicated that disconnecting the infill plate from the Vertical Boundary Element (VBE) can decrease the demands on the column. The observed outcomes lead to a decline in both the energy dissipation capability and the lateral load-bearing capacity. The primary goal of this investigation is to mitigate stress on the column while concurrently reducing both the energy dissipation and lateral force capacities. To accomplish this, a partial connection will be established between the infill plate and the Vertical Boundary Element. Thus, the overarching objective of this research is to identify the optimal connection length that minimizes the demands on the column while simultaneously curtailing the reduction in energy dissipation and lateral force capacities. Using Abaqus software, twenty models with different infill plate thicknesses and lengths of connection between the infill plate and Vertical Boundary Element were analysed. To determine the optimal length of connection between the infill plate and Vertical Boundary Element, the energy dissipation capacity, lateral load capacity, and column stresses were evaluated and compared. The maximum dissipation of energy occurs at a connection length of 75% between the infill plate and Vertical Boundary Element and an infill plate thickness of 12 mm. In contrast, the greatest lateral load capacity is achieved at connection lengths of 50% between a 25 mm infill plate thickness and a Vertical Boundary Element weight of 25%. The column stress reaches its minimum value when the infill plate measures 20 and 25 mm, and it reaches its maximum value when the infill plate measures 6 mm and 12 mm. By increasing the thickness of the infill plate and minimizing its connection to the Vertical Boundary Elements, the column stress in Vertical Boundary Elements can be decreased, while simultaneously enhancing lateral load capacity and maintaining an adequate level of energy dissipation.

Articular cartilage fatigue causes frequency-dependent softening and crack extension

Soft biological polymers, such as articular cartilage, possess exceptional fracture and fatigue resistance, offering inspiration for the development of novel materials. However, we lack a detailed understanding of changes in cartilage material behavior and of crack propagation following cyclic compressive loading. We investigated the structure and mechanical behavior of cartilage as a function of loading frequency and number of cycles. Microcracks were initiated in cartilage samples using microindentation, then cracks were extended under cyclic compression. Thickness, apparent stiffness, energy dissipation, phase angle, and crack length were measured to determine the effects of cyclic loading at two frequencies (1 Hz and 5 Hz). To capture the fatigue-induced material response (thickness, stiffness, energy dissipation, and phase angle), material properties were compared between pre-and-post diagnostic tests. The findings indicate that irreversible structural damage (reduced thickness), cartilage softening (reduced apparent stiffness), and reduced energy dissipation (including phase angle) increased with an increase in the number of cycles. Higher frequency loading resulted in less reduction in energy dissipation, phase angle, and thickness change. Crack lengths, quantified through brightfield imaging, increased with number of cycles and frequency. This study sheds light on the complex response of cartilage under cyclic loading resulting in softening, structural damage, and altered dynamic behavior. The findings provide better understanding of failure mechanisms in cartilage and thus may help in diagnosis and treatment of osteoarthritis.

Issues and Challenges in Small-Signal Low-Power Amplifiers: A Review

Background: Contemporary linear electronic circuit designs frequently include small-signal low-power amplifiers as a fundamental building block. These amplifiers are widely used as LNAs (Low Noise Amplifiers) in the pre-amplifier stages of both low-frequency and high-frequency featured electronic circuits. Objectives: To review the recent advances in the design of small-signal low-power amplifiers based on device configuration of BJTs, JFETs and MOSFETs for low (≤1KHz) and high frequencies (≥1MHz) at smaller input voltage (<1 Volt). Methods: The articles published between 2010 to 2024 are shortlisted from IEEE Xplore, Springer, Science Direct Elsevier, Google Scholar, and MDPI databases and the outcomes of the different techniques are compared on various parameters. Findings: It is found that four-stage CMOS amplifier at TSMC 40nm process technology emerges with highest 84.59dB gain, InP (Indium Phosphide) Distributed Amplifier Using 3-D Interdigital Capacitors carries widest bandwidth of 160 GHz, two stage darlington pair amplifier at 0.18μm under dual input and dual output topologies and four stage CMOS amplifier at 40nm technology realizes lower power consumption of 0.5mW and 0.00086 mW respectively. Small Signal Amplifier based on single stage BJT-JFET Sziklai pair operates at lowest frequency of 11.36 Hz, single stage LNA at 180nm CMOS technology using inductive degenerate topology works at very low supply voltage at +0.5V and, recently reported complementary sziklai based small signal amplifier under CC mode works at lowest -15V supply voltage. Novelty: The review proposed on ‘Small Signal Low Power Amplifier’ is first time reported in this paper. Moreover, it discusses low power small signal amplifiers at both low (≤1KHz) and high (≥MHz) frequencies considering gain enhancement technique, power dissipation reduction technique, and noise reduction technique whereas other review papers emphasize on the general discussion of different topologies only at high frequencies. Keywords: Small-Signal Amplifiers, Low Power Amplifiers, BJTs, JFETs, MOSFETs

Quantum Correlation Enhanced with Quantum Coherent Feedback Control in a Cavity‐magnon Hybrid System

AbstractA scheme is proposed to enhance quantum correlation, including entanglement and steering, for two magnon modes in a cavity‐magnon hybrid system through coherent quantum feedback. The hybrid system consists of a microwave cavity and two YIG spheres, which incorporates a nonlinear flux‐driven Josephson parametric amplifier in order for the generation of two photons within the cavity simultaneously. A quantum coherent feedback loop is used for the reduction of effective dissipation. By modulating feedback parameters, optimal bipartite and tripartite entanglement, as well as quantum steering are derived. Importantly, compared with the same setup without coherent feedback, the proposed scheme significantly improves quantum correlation. Furthermore, by optimizing the feedback reflectivity and the ratio of cavity‐magnon coupling strength, the enhancement of asymmetric steering can be controlled. Notably, incorporating the feedback loop effectively increase its robustness against thermal noise, thus the scheme offer better prospect for experimental development. This study paves the way for advancements in quantum information processing and quantum entanglement within cavity‐magnonics.

Fatigue investigations of elastomers developed for high-pressure hydrogen gas environments

Hydrogen possesses many characteristics to be an ideal candidate as a more sustainable energy carrier, especially for the transport sector. For a proper optimization of this abundant resource, hydrogen needs to be compressed, and stored in high-pressure conditions, which demands improvement in technology and the development of appropriate materials. In this context, elastomeric sealing components play a critical role and they need to withstand harsh working conditions, for example, high-pressure, wide temperature range, cyclic exposure conditions, etc. In this work, eight different grades designed for this application were analyzed in terms of fatigue behavior and long-term performance. This was verified through fatigue crack growth experiments, the energy dissipation, and temperature increase during crack propagation were analyzed and correlated with micro-structural differences of materials. Furthermore, the materials were investigated at large and small deformations through uniaxial tensile tests and Dynamic Mechanical Analysis (DMA), respectively. It was found that only with the addition of a coupling agent can silica-filled NBR have properties similar to carbon black (CB) filled NBR, despite a reduction in both fatigue strength and energy dissipation. Coupling agents also involved an increase in bound rubber. Regarding CB-filled compounds, with peroxide crosslinking a reduction in fatigue strength was found, while no effect on the quantity of bound rubber was observed. Increased CB content in NBR grades led to decreased fatigue resistance and higher energy dissipation; higher bound rubber content was found as well. Also for EPDM grades, increased CB content resulted in reduced fatigue resistance. Despite an increase in energy dissipation, the content of bounded rubber was the same even with higher CB content.

Analysis and experimental evaluation of an inertial eddy current damper for vibration control

Electromagnetic damping features non-contact operation, easy adjustability, convenient processing, and high energy consumption. Combined with the damping efficiency enhancement effect of the inertial system, it is conducive to further improving its damping effect. This paper proposes an inertial mass damper, named the Inertial Eddy Current Damper (IECD). The proposed IECD has the advantage of adjustability, meaning that the eddy current damping force can be adjusted by regulating the current in the coil. First, the mechanical model of the IECD was proposed through theoretical methods. Secondly, performance tests were conducted to verify the accuracy of the proposed mechanical model. Finally, numerical models of structures employing various applications of the IECD were established to conduct seismic response analysis. The results show that the proposed mechanical model effectively reflects the actual performance of the IECD. When used for energy dissipation and vibration reduction, the IECD demonstrates superior control performance in terms of displacement and velocity compared to the LVD, and the switch control strategy can address the issue of poor acceleration control performance. Combining the IECD with isolation bearings not only further reduces the seismic response of the superstructure but also enhances the safety of the isolation bearings, preventing excessive deformation.

Threshold Inverter Quantizer-Based 2-Bit Comparator using Spatial Wavefunction Switched (SWS) FET Inverters: Power Dissipation Analysis

This paper aims to assess the power dissipation of a threshold quantizer (TIQ) 2-bit-based comparator using a SWS-FET-based inverter [1, 2, 4, 5]. Unlike conventional comparators, SWS-based comparator functionalized with TIQ comprises two or more vertically stacked quantum dots or well channels [1-3, 5, 6]. Herein, power dissipation analysis of the simulated circuit is carried out using Cadence by integrating the Berkeley Short-Channel IGFET Model (BSIM) and the analog behavioral model (ABM) [1,3,4,9]. The transient behavior of the inverter circuit is evaluated using 180 nm technology node. Our results demonstrated a significant reduction in power dissipation which overcome the limitation of previous 4-state logic implementations.

Microstructural and micromechanical evolution features of asphalt with aging: An atomic force microscopy study

This study explores the aging effects on matrix asphalt (MA) and styrene-butadiene-styrene modified asphalt (SBSMA) using atomic force microscopy (AFM). Aging was simulated with the rolling thin-film oven test (RTFOT) and the pressure aging vessel (PAV) test. Key changes in microtopography, surface roughness, adhesive forces, Young's modulus, and energy dissipation were analyzed. The findings reveal significant microstructural changes with aging, including an increase in the size and a decrease in the number of beelike structures, increased surface roughness, and Young's modulus, which indicate material hardening. The analysis shows a reduction in adhesive force and energy dissipation, suggesting increased brittleness and viscosity. Notably, SBSMA exhibits better aging resistance than MA, as demonstrated by its lower roughness, stronger adhesive forces, and less reduction in energy dissipation, highlighting the effectiveness of the SBS modifier in mitigating aging impacts. These results underscore the critical role of material composition in the aging behavior of asphalt binders.

Enhanced schemes for resolution of the continuity equation in projection-based SPH

To the best knowledge of the authors, the numerical resolution of the continuity equation, i.e., the simultaneous achievement of accurate and physically consistent velocity divergence and density fields, has not been investigated in the context of projection-based particle methods. In this study, based on the Velocity-divergence Error Mitigating (VEM)/Volume Conservation Shifting (VCS) schemes developed for the WCSPH method, which improve the numerical resolution of the continuity equation, VEM/VCS schemes are proposed for projection-based particle methods. Furthermore, two other novel schemes are introduced. First, a Dynamic VEM (DVEM) scheme is proposed, where VEM is dynamically activated only when the velocity divergence instantaneously diverge from the reference solution at individual particles. The second scheme is referred to as Enhanced VCS by reference density (EVCS), where precise imposition of dynamic free surface boundary condition is considered. Several benchmark tests with different features have been conducted, and it is shown that the proposed schemes enhance the numerical resolution of the continuity equation for incompressible flows, i.e., the divergence free velocity and the constant density conditions. Application of DVEM and EVCS has provided enhanced resolution of the continuity equation along with clear reductions in the numerical energy dissipation associated with the approximated additional numerical terms.

A Power-Efficient Envelope-Detector-Less Amplitude-Shift-Keying Forward Telemetry for Wirelessly Powered Biomedical Devices.

This paper proposes an envelope-detector-less (EDL) amplitude-shift-keying (ASK) forward telemetry (FT) demodulator for wireless power/data transfer (WPDT) systems. The EDL ASK FT demodulator can substitute bulky and power-hungry components, which are an envelope detector and an analog comparator in the conventional ASK FT demodulator, with a digital controller, reducing both power dissipation and chip area. The proposed demodulator shares the gate control signals of pass transistors, which are used in an ac-dc regulator for wireless power reception, to maintain a constant load voltage while efficiently demodulating the forward telemetry data. Also, a proposed digital cleaner in the EDL demodulator refines this control signal into a wide pulse without suffering from resonant frequency noise, while a synchronizer can align its frequency with the data rate and resonant frequency. The 0.25-μm CMOS prototype chip of the proposed power-path-less EDL ASK FT demodulator, equipped with the ac-dc regulator, demonstrates a significant 38.2% reduction in power dissipation compared to the conventional ASK FT demodulator. Moreover, the EDL ASK FT demodulator occupies only 0.023-mm2 silicon area and achieves a low bit error rate (BER) less than 10-4 while maintaining a regulated voltage of 4.5 V on the load.

Analyzing the adjustment mechanism of daily sediment content under large reservoir operations

Adjustment of daily discharge and sediment content in the Lower Jinsha River Basin has changed dramatically. However, the adjustment mechanism of daily sediment content under reservoir operation remains unclear. The Double Mass Curve (DMS) method was used to divide different periods of daily discharge-sediment content relationship change, and the Flow Duration Curve (FDC) was used to calculate the energy dissipation of streamflow by reservoirs. With the operation of large reservoirs, the average flood discharge and its proportion significantly decreased. With the variation in flow regime, the quantile relationship and Lower boundary relationship of daily discharge and sediment content both showed a downward trend, from 1999 to 2019. Under different periods, adjustment of the cross-flow profile was decreased with larger daily discharge, which was characterized by the ratio of sediment content to the lower boundary. An improved flow duration curve method was proposed to calculate the energy dissipation of streamflow. We discovered a novel model between the relative reduction of sediment content and relative energy dissipation of the daily discharge regime, with a good fitness of 0.97. In this study, the effect of the flow regime constructed on sediment content change was emphasized. It is helpful to evaluate the sediment reduction of the total basin caused by reservoirs.

Pinpointing the role of wave period in vegetation induced wave attenuation

Nature-based coastal protection that integrates vegetated wetlands for wave attenuation and erosion mitigation shows great potential. However, there is a lack of consensus on whether longer wave periods contribute to an increase or a reduction in the attenuation of waves in vegetated wetlands, which is primarily due to the disregard of vegetation submersion states. In the current study, we modified a classic model to pinpoint the conditional role of the period. Wave attenuation by vegetation is quantified as the product of two terms: wave decay rate and time of wave group travel through a unit length. By tracing the dynamics of these two terms, the model is in good agreement with the measurements and can well explain why wave attenuation increased with longer period (from 2 to 10 s) in submerged canopies (up to 10 times) but decreased in emergent canopies (by 75%). A maximum response period (2–10 s) was found, beyond which period has no effect on wave attenuation. Furthermore, we found that in field conditions, the variation in wave period can lead to a sharp reduction in wave dissipation. which is critical for coastal safety. For instance, a 62% decrease in wave period at Galveston Island corresponded to a 40% drop in wave dissipation. This work provides a comprehensive understanding on the role of wave period in wave dissipation by wetland vegetation, which would assist in safely implementing wetlands for coastal defence.

Study on Vibration Reduction Effect of the Building Structure Equipped with Intermediate Column–Lever Viscous Damper

Generally speaking, the traditional lever amplification damping system is installed between adjacent columns in a building, which occupies a significant amount of space in the building. In contrast to amplification devices in different forms, the damper displacement of the intermediate column damper system is smaller, and the vibration reduction efficiency is lower. In light of these drawbacks, this study proposes a new amplification device for energy dissipation and vibration reduction, which is based on an intermediate column–lever mechanism with a viscous damper (CLVD). Initially, a specific simplified mechanical model of CLVD is derived. Subsequently, an equivalent Kelvin mechanical model of CLVD is derived to intuitively reflect CLVD’s damping and stiffness effect. The damping ratio added by CLVDs to the structure is calculated according to that model; the additional damping ratio and additional stiffness are utilized to calculate the displacement ratio Rd and shear force ratio Rv of the structure with CLVDs to the structure without CLVDs. Rd and Rv are introduced to evaluate the vibration reduction effect of the structure with CLVDs, and the effects of various parameters (such as intermediate column position, beam’s bending line stiffness, lever amplification factor, damping coefficient, and earthquake intensity) on Rd and Rv are analyzed. The results indicate that when the ratio of the distance from the intermediate column to the edge column to the span of the beam is 0.5, CLVD owns the optimal vibration reduction effect. Increasing the beam’s bending line stiffness is beneficial for CLVD to control structural displacement and shear force; when the leverage amplification factor is too large, the CLVD provides the structure with stiffness as the main factor, followed by damping. Additionally, when the ratio of the displacement amplification factor to the geometric amplification factor satisfies fd/γ = 1/21−0.5α, the CLVD has the optimal displacement control effect on the structure. After that, measures are provided to optimize the CLVD in different situations in order to effectively control the inter-story displacement and the story shear force of the structure. Consequently, a nine-story frame is taken as an example to elaborate the application of CLVDs in the design for energy dissipation and vibration reduction. The results reveal that the CLVD scheme adopting the proposed optimization method can effectively enhance the displacement amplification ability of CLVDs, resulting in an additional damping ratio of up to 12%. At the same time, the inter-story displacement was reduced by almost 40% under fortification earthquakes. Through the research in this study, designers can obtain a new choice in structural vibration reduction design.

Bamboo-inspired lightweight, mechanically-stable and vibration-damping structural members for engineering applications

After millions of years of natural evolution, bamboo stems have formed exquisite variable cross-section hollow multi-node structures that are lightweight, tough, and stable. Bamboo is difficult to break and damage from the roots under dynamic loads, providing an important reference for te biomimetic design of lightweight components. This paper investigates the structural characteristics and variation patterns of bamboo stems and subsequently proposes an imitation bamboo stem structure design strategy for engineering structural members, namely, imitation bamboo double-jointed columns (IDJC). We establish a macro scale finite element model to predict the mechanical properties and failure modes of the IDJC under cyclic bending loads, and validate the model using experimental and analytical methods. The simulation and experimental results show that compared with traditional double-jointed columns (DJC), the weight of the IDJC is reduced by 41.7 %. Under bending load, the compressive stress of each section is approximately equal, reducing stress concentration, and increasing bending resistance. The strength to weight ratio of IDJC is 1.96 times that of DJC, indicating lightweight and high-strength characteristics. The stiffness degradation, energy dissipation, and damping and vibration reduction performance of the IDJC were also evaluated. The results showed that compared with the DJC, the stiffness degradation rate of the IDJC decreased by 6.87 times, the energy dissipation rate increased by 1.07 times, and the damping and vibration reduction performance improved by 48.40 %, reflecting a high stability and robust vibration reduction performance. The results demonstrate the potential application of biomimetic structures for the development and design of resource-rich, low-carbon, and sustainable bamboo for bamboo engineering members with excellent performance and functionality. Biomimetic structures have great potential in replacing nonrenewable structural materials in the fields of civil engineering and transportation.

Die Casting of Lightweight Thin Fin Heat Sink Using Al-25%Si

The demand for lightweight and cost-effective heat sinks is increasing. A typical method for economically manufacturing complex-shape heat sinks is die casting. To reduce the weight of the die-cast heat sinks, thinning the fins and base is common practice. We experimented with casting heat sinks using Al-25%Si in a conventional die casting machine with the aim of economically producing thinner fins and bases. Compared with the aluminum alloy used in conventional die casting, Al-25%Si has superior fluidity, which is proven to be very useful for reducing the thickness of the fins and base. As a result, we successfully reduced the heat sink weight using Al-25%Si and a conventional die casting machine. To investigate the properties of the produced Al-25%Si thin fin heat sink, we compared the effects of fin thickness, fin height, number of fins, and base thickness on heat dissipation and weight reduction. Additionally, we compared the weight and heat dissipation properties with those of a commercial heat sink and found that our Al-25%Si heat sink maintains the same heat dissipation performance but for 35% lower weight.

Moth Flame Algorithm to Optimize the Size and Location of Energy Storage Units in a Radial Distribution Network to mitigate Power Loss

The ideal placements and capacities for Battery Energy Storage Systems (BESS) sources in a distributed generation (DG) environment have an impact on power losses in the distribution network. Therefore, engineers are quite concerned with DG and BESS. The output from DG is, however, typically unpredictable and inconsistent. The secure and stable functioning of the power system will be impacted to varying degrees when it is connected to various sites, capabilities, and power grids. To provide a safer, more stable, more dependable, as well as more effective power grid operation, power grid planners must take the impact of capacity, type, and location into account while choosing the best BESS accessibility method. The objective is to choose bus stops with the right potential and minimal loss. This study demonstrates how to use a Moth Flame Optimization Algorithm (MFOA) to establish the appropriate battery energy storage system (BESS) sizing in a hybrid solar and wind energy conversion system (WECS) generation integrated in a radial distribution network. This research investigates the optimal capacities and allotment of the BESSs within a 33-bus and 69-bus radial network of distribution for the maximum power dissipation reduction. This research also provides a framework for carrying out conservation voltage reduction (CVR) when distributed energy resources like solar photovoltaic (PV) systems, WECS, and energy storage systems (ESSs) are connected into distribution networks. The simulation has been conducted using Matlab code and the suggested method's output is compared with Firefly Algorithm (FA), Genetic Algorithm (GA) and Ant Colony Algorithms (ACA) and evaluated against other results.

Multi-objective optimization of electro-pneumatic braking process with fuzzy logic control for heavy haul railway applications

ABSTRACT This paper presents a novel approach to multi-objective optimization in heavy haul trains’ electro-pneumatic braking systems using optimizable fuzzy control. Initial findings indicate that a straightforward replacement of pneumatically controlled valves with electro-pneumatic ones, without significant control schedule modifications, fails to substantially improve the dynamics behaviour of rolling-stock. Consequently, a more sophisticated strategy based on optimizable fuzzy logic control for the electro-pneumatic valves was developed. This approach utilizes multi-objective optimization to simultaneously minimize energy dissipation during braking and reduce force peaks in freight car draft gears. The optimal solution achieved demonstrates a 13.41% reduction in kinetic energy dissipation during downhill sections, along with a concurrent decrease in draft gear peak forces by 14.22% in traction and 3.16% in buff regimes compared to standard rolling-stock with pneumatically controlled valves. This optimized fuzzy braking controller outperforms standard procedures, highlighting its potential to enhance heavy haul train efficiency while adhering to safety standards.