Expansion Of System Research Articles

Design and simulation of a compact plasmonic photonic crystal fiber filter with wide band and high extinction ratio

In order to realize the performance optimization and function expansion of modern all-optical systems, this work presents a compact plasmonic photonic crystal fiber (PCF) filter, using finite element tool. The deposited gold and graphene layers within the elliptical pores interact with the transmitted light, creating surface plasmon resonance (SPR) effect that amplifies the energy difference between x- and y-polarized light greatly. The simulation results indicate that the structural parameters are configured with the cladding holes' diameter of 0.6 μm, the large-holes’ diameter of 1.2 μm, the inner small-holes’ diameter of 0.2 μm, the lattice constant of 2.0 μm, the elliptical holes' minor axis length of 0.45 μm, the elliptical holes' major axis length of 1.30 μm, the gold layer thickness of 50 nm, and the graphene layer thickness of 20 nm, the central wavelength of the proposed PCF filter is 1.56 μm. When the length of this PCF filter is 1 mm, a maximum extinction ratio (ER) of 133 dB, an operating bandwidth exceeding 800 nm, covering two common communication windows of 1.31 μm and 1.55 μm, as well as a low insertion loss (IL) of 0.59 dB can be achieved. What's more, the feasibility of fabricating the device is also examined. This filter with compactness, broadband and high-extinction demonstrates promising applications in optical communication, optical sensing, optical computing, and various other fields.

Experimental analysis of a multi-phase resonance-based fault current limiter prototype under symmetrical and asymmetrical faults

Expansion of power systems and involving more distributed generation cause to increase in fault current levels. This paper presents a three-phase resonance-based solid-state fault current limiter (FCL) prototype that has series and parallel resonance modes developed to suppress fault currents of power systems. The laboratory-scaled prototype is located on a three-phase test circuit and has been examined with the fault types of three-phase, three phase-to-ground, two phase-to-ground, and phase-to-ground. The performance and effectiveness of the proposed series-parallel resonance-type fault current limiter (SPRFCL) are validated with the comparison of Matlab/Simulink simulations and experimental test results. Fault currents in different types of faults are limited to an allowable value at high rates and experimental results are considerably close to current values obtained from each fault simulation. Fault currents of faulted phases are restricted with the limiting rates ranging from 75 % to 85 % concerning prospective fault currents in the non-FCL situations. Short-circuit test results of the prototype of SPRFCL that is supplied from a 380 V grid revealed that it acts stable and successful operation regardless of fault type. Accordingly, it has a favorable circuit design for power system applications.

Large-scale deorphanization of Nematostella vectensis neuropeptide G protein-coupled receptors supports the independent expansion of bilaterian and cnidarian peptidergic systems.

Neuropeptides are ancient signaling molecules in animals but only few peptide receptors are known outside bilaterians. Cnidarians possess a large number of G protein-coupled receptors (GPCRs) - the most common receptors of bilaterian neuropeptides - but most of these remain orphan with no known ligands. We searched for neuropeptides in the sea anemone Nematostella vectensis and created a library of 64 peptides derived from 33 precursors. In a large-scale pharmacological screen with these peptides and 161 N. vectensis GPCRs, we identified 31 receptors specifically activated by 1 to 3 of 14 peptides. Mapping GPCR and neuropeptide expression to single-cell sequencing data revealed how cnidarian tissues are extensively connected by multilayer peptidergic networks. Phylogenetic analysis identified no direct orthology to bilaterian peptidergic systems and supports the independent expansion of neuropeptide signaling in cnidarians from a few ancestral peptide-receptor pairs.

Large-scale deorphanization of Nematostella vectensis neuropeptide G protein-coupled receptors supports the independent expansion of bilaterian and cnidarian peptidergic systems

Neuropeptides are ancient signaling molecules in animals but only few peptide receptors are known outside bilaterians. Cnidarians possess a large number of G protein-coupled receptors (GPCRs) – the most common receptors of bilaterian neuropeptides – but most of these remain orphan with no known ligands. We searched for neuropeptides in the sea anemone Nematostella vectensis and created a library of 64 peptides derived from 33 precursors. In a large-scale pharmacological screen with these peptides and 161 N. vectensis GPCRs, we identified 31 receptors specifically activated by 1 to 3 of 14 peptides. Mapping GPCR and neuropeptide expression to single-cell sequencing data revealed how cnidarian tissues are extensively connected by multilayer peptidergic networks. Phylogenetic analysis identified no direct orthology to bilaterian peptidergic systems and supports the independent expansion of neuropeptide signaling in cnidarians from a few ancestral peptide-receptor pairs.

The Global South as a theoretical and methodological marker for scientific inquiry: researching and teaching decolonial peace

How do we know, theorize, and teach the possibilities of peace in the Global South? For most of Eurocentric literature on the topic, peace in the Global South seems like an impossible utopia. Building on Freire’s pedagogy, I argue for a decolonial approach to peace studies centered on the agency of Global South peoples and their power to transform the world. This means that the construction of knowledge around the possibilities for peace are situated in concrete and real struggles of marginalized groups that have been resisting the expansion of violent and oppressive systems, and whose existence and struggles for alternative worlds are an example of “building peace” beyond the neoliberal-Western constraints. The aim of theorizing and learning peace from such perspective is to rescue the liberatory power of the idea of peace away from an imperialist agenda of control and oppression, and towards a liberatory strategy for people and planet.

An AQ-SCS Optimization Assisted Optimal Expansion Planning with Fixed and Switchable Capacitors for Distribution System

Distribution System has given renewable-based DGs like Solar PV and Wind turbines a lot of attention because of growing worries about global warming and the depletion of fossil fuels. This work proposes a unique hybridized optimization technique for a distribution system expansion plan utilizing an innovative theoretical framework. Two stages are used to tackle the issue with the distribution system expansion plan: master optimization and sub-optimization for every state of the system. The developed Aquila based Sand Cat Swarm (Aq-SCS) optimization method considers the distribution system factors, like DG type, size/capacity, location, PQ power, fixed capacitor, switchable capacitor, and the SPV/wind capacity with load demand uncertainties. The sub-algorithm is employed in conjunction with the DG allocation strategy produced by the master algorithm to deduce the state-dependent operating tactics for each individual DG unit with respect to active and reactive power. The suggested Aq-SCS optimization approach is created by combining the properties of the SCSO with the AOA models. The main objective of achieving the minimal possible cost for the DSEP is verified, and the cycle continues unless the best outcome (least cost) is reached. The analysis of the suggested approach is carried out in 4 cases, such as (i) Without DG and capacitor (ii) With capacitor and no DG (iii) With DG and no capacitor (iv) With both capacitor and DG. The analysis is made in IEEE 33 bus system. The Aq-SCS approach outperforms the conservative approaches SSI-CS, WHO, AQO, and SCSO, according to the analysis conducted in MATLAB/Simulink utilizing an IEEE-33 bus system with five system states.

Hard and soft governance mechanisms for large projects. A historical perspective

Purpose Drawing motivation from the greater exposure to uncertainty and condition changes that affect large projects due to their long lifecycle, this paper aims to investigate how the time factor affects the use of governance mechanisms to pursue the success of these projects. Design/methodology/approach To pursue its aim, the article applies the dichotomization between the hard and soft mechanisms of project governance to the analysis of a historical case study, whose findings are organized over the short, medium and long periods. The case selected is referred to the peculiar water system, made up of tunnels named “bottini,” that was in use in Siena (Italy) as the old aqueduct. Specifically, the study focuses on the project of expansion of this water system that was realized during the 14th century for the construction of the “Bottino maestro di Fontegaia.” Findings This article highlights the different relevance that, during the lifecycle of large projects, is assumed by hard and soft governance mechanisms, with the former having main relevance in a short and medium period, and the latter usually emerging in the medium period and, subsequently, playing a growing role for the project success in the long period. Originality/value The article contributes to the literature on large projects by providing novel insights about how the time factor impacts the governance of these projects. Furthermore, the case study, with its unique history, highlights the relevance of combining effectively the hard and the soft dimensions of project governance to pursue success.

Simulation study on hydraulic lifting mechanism of lift-sliding mechanical parking system

A mechanical parking system is an important parking equipment that can improve the utilization rate of urban space. In China, the lift-sliding mechanical parking system is the most widely used. Among many types of drives, the hydraulic pump-hydraulic cylinder type has advantages such as convenient system integration and expansion, energy saving, etc. The system is prone to vibration and pressure shock during operation. This paper focuses on the causes of vibration and hydraulic impact, constructs a simulation model, and analyzes the causes of vibration and hydraulic impact through simulation results, guiding equipment optimization.

Exploring the climate change mitigation potential and regional distribution of agrivoltaics with geodata-based farm economic modelling and life cycle assessment

Tackling climate change remains a critical challenge for society. Achieving climate neutrality requires a massive expansion of renewable energies such as wind and photovoltaics (PV). Agriculture plays a key role in this context, especially as the expansion of ground-mounted PV systems often leads to land-use conflicts. Agrivoltaics (AV), which combines agricultural and electricity production, can be a solution, but the synergies are particularly dependent on local agronomic conditions. There is also a knowledge gap in how AV expansion impacts greenhouse gas (GHG) emissions at the landscape level and how it contributes to regional emission reduction targets. In this study, we analysed the economic and climate change mitigation impacts of AV expansion pathways in the German state Baden-Württemberg using an integrated land use model and life cycle assessment under the assumption of general rentability of electricity production by AV. We found that implementing AV on 1%–5% of the regions's arable and grassland area reduced the total agricultural gross margin by a maximum of approximately 0.5%. Concurrently, AV implementation reduced GHG emissions by about 1.2 million to 5.9 million metric tons of CO2 equivalent (Mt CO2-eq). Even if this reduction is almost exclusively accounted for in the energy sector, in absolute terms it amounts to more than the current GHG emissions from Baden-Württemberg's agricultural sector (about 4.4 Mt CO2-eq in 2021). In the 5% expansion scenario, almost 90% of the installations were installed on grassland, but this share dropped to 72% when considering landscape quality constraints. Although we found considerable regional disparity, our findings still suggest that AV is an essential component for regional emission reduction targets. These results are particularly relevant for policymakers in spatial planning, agricultural and energy policy.

Financial inclusion and the contested infrastructures of cash transfer payments in South Africa

Across much of the South, digital technologies are increasingly central to the expansion of state social protection systems. Supported by major development agencies, many of these distributive technologies are developed and implemented by financial technology companies with the specific aim of accelerating financial inclusion. While researchers have documented the influence of these financial actors and logics over social policy, we know less about how these interventions are transforming the experience of receiving social protection. Based on qualitative and observational research with social grant recipients in South Africa, this research demonstrates how digital and financial technologies produce confusion, informational opacities and new forms of exclusion among grant recipients. It suggests that the increasingly prominent role of financial technologies in the delivery of social protection undermines state capacity and further entrenches the influence of neoliberal logics over social policy. Finally, the article suggests that these technologies may be transforming the nature of social citizenship in South Africa, undermining efforts to advance universal and redistributive social protection policies.

Eco-physiological behaviors of some apple genotypes (Malus x domestica Borkh.) in the hot-and-dry climate of an inner area of Southern Italy

The Italian internal areas are distant from the main trade flows and service centers, but have important environmental and cultural resources. The Italian “National Strategy for Inner Areas” represents a novel policy aimed at contrast the abandon of these territories by supporting multiple activities aimed at stimulating economic development and promoting territorial cohesion. The condition of marginality offers the chance to pursue economic development according to the principles of sustainability. These internal areas are often distinguished by a purely rural vocation. Genotypes of fruit crops traditionally grown in inland areas cope often with difficult climatic conditions and low-input farming techniques, showing generally a good tolerance to abiotic tresses. Exploring their eco-physiological behaviors in response to the agri-environmental context is useful for identifying crops capable of stimulating the recovery and expansion of a sustainable agriculture system in inland areas. The present work reports some results of a research conducted on three traditional local apple genotypes grown in an internal hot-arid summer area of Southern Italy, evaluating their water status and the intensity of leaf gas exchange compared to those of a well-known “standard” cultivar, in a hot, dry summer period. The local genotypes tested in this case study proved to be more eco-physiologically performing. The experiment allowed to estimate their probable relative eco-physiological advantages compared to the “standard” apple genotype taken as reference.

Exploring transitions of sewer wastewater infrastructure towards decentralisation using the modular model TURN-Sewers

We present a new modular model called TURN-Sewers for exploring different adaptations of centralised wastewater infrastructure towards more decentralised wastewater systems under different urban development scenarios. The modular model is flexible and computationally efficient in exploring transitions at the city scale, allowing for the comparison of different policies and management strategies for sanitary wastewater infrastructure. TURN-Sewers includes independent modules that simulate the generation, dimensioning, deterioration, management, and calculation of performance indicators for different wastewater systems. This model can use readily available spatial information to support infrastructure planners and other stakeholders in exploring different transition pathways from centralised to decentralised wastewater infrastructure. An illustrative example demonstrates how TURN-Sewers can generate multiple future alternatives, define different infrastructure management strategies regarding system expansion, rehabilitation and transition, and assess the economic, hydraulic and structural impacts.

A Coordinated Control Strategy of Multi-Type Flexible Resources and Under-Frequency Load Shedding for Active Power Balance

With the increasing expansion of power systems, there is a growing trend towards active distribution networks for decentralized power generation and energy management. However, the instability of distributed renewable energy introduces complexity to power system operation. The active symmetry and balance of power systems are becoming increasingly important. This paper focuses on the characteristics of distributed resources and under-frequency load shedding, and a coordinated operation and control strategy based on the rapid adjustment of energy storage power is proposed. The characteristics of various controllable resources are analyzed to explore the rapid response capabilities of energy storage. The energy storage types are categorized based on the support time, and the final decision is achieved with power allocation and adjustment control of the energy storage system. Additionally, a comprehensive control strategy for under-frequency load shedding and hierarchical systems is provided for scenarios with insufficient active support. The feasibility of the proposed model and methods is verified via a multi-energy system case.

Visual explanations of machine learning model estimating charge states in quantum dots

Charge state recognition in quantum dot devices is important in the preparation of quantum bits for quantum information processing. Toward auto-tuning of larger-scale quantum devices, automatic charge state recognition by machine learning has been demonstrated. For further development of this technology, an understanding of the operation of the machine learning model, which is usually a black box, will be useful. In this study, we analyze the explainability of the machine learning model estimating charge states in quantum dots by gradient weighted class activation mapping. This technique highlights the important regions in the image for predicting the class. The model predicts the state based on the change transition lines, indicating that human-like recognition is realized. We also demonstrate improvements of the model by utilizing feedback from the mapping results. Due to the simplicity of our simulation and pre-processing methods, our approach offers scalability without significant additional simulation costs, demonstrating its suitability for future quantum dot system expansions.

Towards CSP technology modeling in power system expansion planning

Power systems with a high level of renewable energy penetration face challenges due to the inherent properties of some renewable energy sources, such as their variability and uncertainty. These systems require reliable technologies capable of handling large ramps and flexibility needs. Concentrating Solar Power (CSP) has been identified as one solution, which has been researched and implemented in several countries. This paper presents a novel analysis and evaluation of the impacts of choosing an inadequate representation of CSP technology in power system planning tools. The current state of CSP in power system expansion planning in the literature is examined, providing a classification for the modeling of investment and operation of CSP plants. Based on a proposed analysis framework, different models and configurations for CSP plants are evaluated and applied to a 5-bus test system. One of the key findings is that the selected model highly impacts the computational effort (150% more processing time), the quality of the planning decision (14% more overall costs), and the total emissions (up to 52% more emissions). A storage-based model proves to be the most suitable option, considering the operation and investment costs, as well as computational burden. The selected model achieves a 1% error compared to the results obtained with a reference model, while also requiring 40% less computation effort. The proposed framework can be applied to other power system structures by choosing the best suited CSP modeling.

Unraveling mechanisms and failures of stray current corrosion in urban Subway adjacent pipeline networks through statistical insights and 3D simulation

The escalating expansion of urban subway systems in recent years has accentuated the issue of stray current corrosion within pipeline networks, emerging as a critical concern for urban safety. This paper delves into the intricate interplay between these phenomena, employing data-driven statistical analyses to elucidate the coupling characteristics between subway lines and the occurrence of failures in adjacent buried pipelines. An advanced three-dimensional finite element model was developed for stray current corrosion in pipelines, seamlessly integrating empirical data and physics-based modeling, which is to uncover the spatial nuances and multifaceted impacts on subway pipeline corrosion from both macro and micro perspectives under varying influencing factors. The study unveils a pronounced geographical and functional affinity between urban subway networks and metallic pipeline networks. The coupling attributes between subway systems and pipelines, such as distance, angle, and pipeline-specific characteristics including material and age, assume pivotal roles. The results further emphasize the hierarchical order of influence, with stray current intensity holding the greatest sway, followed by the distance between subway and pipelines, the angle between them, and soil resistivity. This paper offers a comprehensive investigation of the interrelationships and influential factors between subway systems and adjacent pipelines. It contributes to the mitigation and management of stray current corrosion in pipelines induced by nearby rail transit, thereby enhancing the resilience of both subway and pipeline networks within urban areas.

Model order reduction for discrete time-delay systems based on Laguerre function expansion

We investigate model order reduction for discrete time-delay systems via orthogonal polynomial expansion in the frequency domain. The transfer function of systems is expanded in the framework of Laguerre function basis. We show that Laguerre coefficients of the states satisfy a linear system and reduced models generated by projection methods can preserve some Laguerre coefficients of the original systems. We prove that the subspace spanned by Laguerre coefficients is exactly a high order Krylov subspace, thereby leading to an efficient computation of projection matrices and a more accurate coefficient-matching property in the two-sided framework. Further the Laguerre expansion of systems is employed to enable an approximate but fast execution of balanced truncation for discrete time-delay systems. Specifically, Gramians are approximated based on the derived Laguerre coefficients, which circumvents the main bottleneck of balanced truncation methods. Finally, two numerical examples are simulated to demonstrate the feasibility and effectiveness of the proposed methods.

Environmental Impact Assessment of Chiplet-Based VLSI

In this paper, we explore the revolutionary shift in VLSI design brought about by chiplet-based architectures, which are superior to the older, single-piece designs in many ways. This type of architecture not only boosts performance and allows for greater system expansion but also plays a significant role in promoting environmental sustainability. Chiplet-based designs lead to more resource-efficient, less wasteful, and more energy-efficient semiconductor technologies, steering the industry towards a more environmentally friendly path. The adoption of eco-chips enhances these environmental benefits, leading to a notable decrease in the carbon emissions associated with electronic devices and systems. This shift is pivotal in achieving the twin goals of advancing technology and upholding environmental stewardship in VLSI. We introduce HI as a strategy for achieving sustainable computing, creating chiplet-based systems that have a smaller carbon footprint than traditional System on Chips (SoCs). We also present ECO-CHIP, a tool we developed for estimating the carbon footprint of these systems, accounting for both their construction and operational phases, including the carbon costs of advanced packaging. In Section VI, we illustrate how ECO-CHIP can be used for breaking down systems into smaller parts and for exploring different design options, and we have integrated it with other tools for estimating the costs of chiplet-based designs. ECO-CHIP is freely available as open-source software and can be found in an anonymous repository [21]. We contend that ECO-CHIP will facilitate the creation of more environmentally friendly design practices for the next generation of complex systems.

Legal Policy for Women Workers in Indonesia: A Review of Contemporary Islamic Law

The Indonesian government issued Regulation in Lieu of Law (Perppu) Number 2 Year 2022 on Job Creation by amending several contents of the regulation. After the issuance of the regulation, attention has been focused on the regulation of the protection of women in law. Therefore, this study aimed to determine the effect of Government Regulation on Job Creation regarding the welfare of women workers in the review of contemporary Islamic law through siyāsah dusturiyāh. The analysis was conducted through library study, using data sources acquired from the literature pertaining to the Government Regulation in Lieu of Law on Job Creation. The results showed that in contemporary Islamic legal study, the concept of siyāsah dusturiyāh emphasized policy formation to achieve benefits measured through Maqasid Shari'ah. According to Perppu, every citizen was able to secure employment and receive fair as well as dignified compensation and treatment in labor relations, including the protection of women workers. However, several aspects did not work in accordance with the objectives and had a negative impact on women workers. These included the threat of low wages, the expansion of the outsourcing system, and the obligation of prolonged leave, which no longer persisted. In this context, Perpu was not consistent with the purpose of the benefit of women workers.

Various Feature-Based Series Direct Current Arc Fault Detection Methods using Intelligence Learning Models and Diverse Domain Exclusion Techniques

The expansion of DC electrical distribution systems necessitates advancements in detecting and mitigating DC arc events, a significant contributor to fire accidents in low-voltage DC distribution systems. Detecting DC arc faults poses considerable challenges, making them a major safety concern in DC power lines. Conventional approaches mainly rely on arc current, which can vary during normal operation, potentially leading to false alarms. Moreover, these methods often require manual adjustment of detection thresholds for different systems, introducing the risk of malfunction. This study proposes an advanced arc fault recognition procedure that extracts and utilizes various key features for the DC arc detection. This work investigated new various features, which are the square average, the average, the median, the rms, the peak-to-peak, and the variance values, to find out which one can be the most effective features to detect the DC arc failure. The results of this detection process show good evidence for the effectiveness and reliability of the proposed malfunction detecting plan.