Sector Configuration Research Articles

Machine learning application for estimating electricity demand by municipality

In order to achieve efficient and low carbon energy systems, attention has been focused on locally distributed energy systems, but a detailed and accurate supply–demand database is essential for simulating and optimizing such local systems. Demand data are generally not maintained at small scales, and it is common to estimate electricity demand by prorating global data from large energy carriers. However, the accuracy of the proration method is questionable. The present study explores the idea of using machine learning as an alternative to the proration method for downscaling electricity demand data based on a neural network model. The input data consist of four categories: weekday/holiday determination data, temperature data, periodic signal data, and demand sector configuration data. The model shows a satisfying generalization capacity for downscaling data from regional to prefectural and municipal scales while capturing local characteristics that are not accounted with the proration method.

Broadband RCS Reduction Using Circular Sector Structure

In this paper, a new metasurface structure is designed to reduce radar cross section (RCS). In order to reduce the radar cross section (RCS), a new metasurface structure is designed. The unit adopts the polarization conversion metasurface structure, which is composed of asymmetric double arrow-shaped metal structure and etched on the dielectric substrate on the back of the metal plate. This polarization conversion metasurface (PCM) unit consists of asymmetric double arrow-shaped metal structure, and it is etched on a dielectric substrate backed with metallic plate. It can realize converting linear polarized waves to orthogonal ones in a broadband from 18.1 GHz to 32.7 GHz efficiently. According to the further development of the triangle chessboard layout, we also designed several new circular fan-shaped configurations, which realize RCS reduction in a wider -10 dB bandwidth compared with the triangle chessboard configuration. Finally, an optimized 8-lobed circular sector configuration composed of the designed PCM unit is selected for processing and testing. It can realize the RCS reduction greater than 10 dB in a wide bandwidth ranging from 13.7 GHz to 27.5 GHz, compared with the equal-sized metallic-backed dielectric substrate plate. The experimental results basically agree with the simulation ones. The proposed broadband circular sector structure has broad application prospects such as phased array antenna technology, electromagnetic stealth technology, and electromagnetic absorption technology.

Breaking the cycle of corruption in Nigeria's electricity sector: Off-grid solutions for local enterprises

Access to electricity is a major constraint to economic growth in Nigeria. Small and medium enterprises (SMEs) are arguably the segment of the Nigerian economy most disadvantaged by a lack of access to reliable power. Due to the failure of grid-based supply, over 80 % of SMEs rely on a generator to power operations. Inclusive, diversified growth in the country depends on growth of the SME sector. This paper examines how SME grid access can be improved given the technical inefficiencies and systemic corruption in the sector. In line with the political settlements framework we provide a macro-analysis of the sector which helps address and identify a solution for the main research problem of how to solve the power constraints Nigerian SMEs face. Our research, conducted between 2018 and 2019, but still valid currently, as the features we describe have not evolved substantially, identifies that the reasons for the failure of grid-based supply is a combination of interdependent factors. Technical inefficiency in the grid is high. Revenue shortfalls have also resulted in extensive government bailouts. These inefficiencies are compounded by ‘legacy’ and recent corruption that has led to poor maintenance of the transmission network during state-ownership and to the presence of politically-connected bidders in the recent privatisation efforts, leading to sub-optimal outcomes. Any solution for SMEs has to take this sectoral configuration into account. Our strategy is supported by focus groups discussions and interviews with over 30 clustered firms in the South Eastern SME hubs of Onitsha, Aba, and Nnewi.

The policy dimension of energy transition: The Brazilian case in promoting renewable energies (2000–2022)

Policies can play a central role in the energy transition by promoting renewable sources. The successful implementation of sustainable energy and climate policies requires political will and public support. Governments in many countries are taking measures to drive changes in energy systems and incentivize renewable energies. Drawing on the Brazilian regulations and the database from the National Agency of Electric Energy, in this article, we examine the public policy design and implementation to boost renewable energy, as well as the emerging configuration of the sectoral governance that stems from energy policies. The installed electricity capacity in Brazil is mostly renewable due to hydropower. However, territorial matters of hydropower plant locations in areas with high biodiversity, the uncertainty about future water availability, and the impact of climate change on water resources impose a challenge on sectoral planning for understanding the spatial and water-energy nexus to avoid unintended consequences, as well as to promote alternative renewable energies. Strategies for expanding alternative sources need to consider, the growing presence of private agents (national and international) in the electricity sectoral configuration, which can shape national policies seeking their interest. Thus, the sectoral policy must seek to engage them in the decarbonization policy. On the other hand, adequate territorial planning, regulations, and policies that may shape the nature of the expansion, pace, and direction of the low-carbon energy transition also need to be considered.

Exploring the role of electrification and modal shift in decarbonizing the road passenger transport in British Columbia

The possibility of the modal shift to public transport and active mobility while considering transport electrification and fuel efficiency improvement has yet to be adequately investigated. This paper explores transition pathways toward an environmentally sustainable road passenger transportation system in the province of British Columbia (BC), Canada. MESSAGE, as a bottom-up energy systems optimization model, is used to find the cost-optimal fuel and technology mix in the transport and power sector. Multiple scenarios mainly assess the influence of modal shift and electric vehicle (EV) diffusion on greenhouse gas emissions by 2050. Besides, the effects of scenarios on the power sector configuration are examined. The results show that BC would not achieve the 80% emissions reduction target in the Climate Change Accountability Act unless by a radical expansion of transport electrification. The target could be met by a minimum diffusion of 70% EVs in the total car stock as well as 35% public transport contribution in total passenger kilometers. The findings also indicate that fully electrified light-duty vehicles coupled with active transport would lead to almost a zero-emission level. Nevertheless, 100% electrification would impose an extra 5.6 TWh burden on the power supply system relative to the business-as-usual scenario.

A New H8 Inverter Topology With Low Common Mode Voltage and Phase Current THD for 3- Induction Motor Drive Applications

Common mode voltage (CMV) reduction in a traditional H6 (six switch) 3-φ inverter usually demands additional power semiconductors to avoid poor harmonic performance. However, apart from tending to the CMV related issues, these extra switches do not add any other capability to the inverter. To address this limitation, in this article, a novel H8 inverter configuration is proposed which not only reduces the CMV by 66.6%, the phase current total harmonic distortion (THD) is also improved. The proposed H8 inverter employs two additional power semiconductor devices along with the conventional H6 inverter in a manner that it can generate 15 space vectors (SV). By considering the CMV attribute of each SV, a unique sector configuration is proposed where the SV diagram is divided into 18 asymmetrical sectors and three distinct SV sequences are identified. A special pulsewidth modulation scheme is devised to operate the proposed topology to achieve reduced CMV and improved harmonic performance. A comparison study reveals that the proposed topology offers better phase current THD, low CMV, low losses, and low semiconductor requirement. Simulation and experimental results are included to justify the various claims.

Care Triangle or Care Diamond? The Case of Childcare and Eldercare in Serbia

Overall changes in political, social and economic spheres in Serbia, along with ongoing demographic processes, have affected various policies and all aspects of people’s lives, including system(s) of care. While care became an important analytical concept and category of social policy analysis internationally, it has not been systematically applied in the analysis of the Serbian welfare state. Incorporation of care in welfare state analysis is much needed as its organisation in the national context reveals a lot about the nature of the welfare state, changes in its socio-institutional arrangements and, most importantly, the effects of provision. This article thus aims to outline the evolution of childcare and eldercare policies in Serbia over the last decade, employing the concept of the care diamond developed by Shahra Razavi, which allows examining the “architecture” through which the care is provided: families/ households, markets, the state and the voluntary sector. By analysing the prevalent care policy “architecture” for children and the elderly in Serbia and the roles of different sectors in that respect, as well as by identifying similarities and differences in the provision of childcare and eldercare in the national context, the article exposes developments and current state in childcare and eldercare provision in Serbia. The analysis indicates the profound role of the informal sphere in both care systems in Serbia, childcare and eldercare. Some differences between the two care domains could also be noted. These relate to the configuration of welfare sectors involved in care provision, revealing the modified shape of the care diamond in the case of childcare. That is, while all four sectors are involved in providing care in the case of eldercare forming an eldercare diamond, this is not the case with childcare. In the latter case, the voluntary, nonprofit sector does not exist as a care provider in Serbia, with childcare “architecture” having a shape of a care triangle. In light of this evidence, the role of families and the voluntary, nonprofit sector should be taken into account in future planning and funding of policies as well as in their implementation. Key words: care, childcare, eldercare, care diamond, policy, provision, Serbia

Effect of Different Fuels on Combustion Instabilities in an Annular Combustor

Abstract Combustion instability in annular combustors of jet engines is a recurring issue. In this study, the characteristics of instabilities for different fuels are investigated by combining the instability maps obtained in a laboratory-scale annular combustor equipped with multiple swirling spray injectors (MICCA-spray) and flame describing functions (FDFs) from a single sector configuration (SICCA-spray). Two types of liquid fuels are injected as hollow cone sprays: heptane, which is fairly volatile, and dodecane, which is less volatile. Experiments are also conducted with gaseous propane, perfectly premixed with air, which serves as a reference. An instability map is systematically drawn by varying the global equivalence ratio and thermal power. The data indicate that the amplitude and frequency of instabilities depend, for the same operating point, on the fuel injection conditions (premixed or spray) and fuel type. Overall trends show that premixed propane is unstable in a broad operating domain. Injection of liquid fuels induces changes in flame time lag that modifies the unstable regions. For heptane, the instability map is closer to the propane reference map, whereas dodecane exhibits wider stable regions. An attempt is made to understand these features by examining the FDF, which gives the ratio of relative fluctuations in heat release rate to the relative fluctuations in velocity. The FDFs measured in a single sector configuration give access to gain and phase information that can be used to determine unstable bands and calculate an instability index guiding the interpretation of the differences in instabilities of the three fuels.

Characteristic analysis of electromagnetic acoustic transducers for helical shear horizontal wave based on magnetostrictive effect.

The electromagnetic ultrasound detection technology provides an efficient method to inspect the structural health status. For the pipeline structure, the guided ultrasonic wave propagating along the axial direction has been the focus of the current research. However, the helical wave owns the advantage of obtaining the defect information in extra angles and has not been explored sufficiently. In this work, a transducer with a sector configuration is designed for generating helical shear horizontal waves in a pipeline. The magnetostrictive effect is analyzed, and the model is built in the finite element simulation software of COMSOL Multiphysics. The electromagnetic field and displacement distribution are studied. To evaluate the performance of the transducer, the half divergence angle is defined to measure the acoustic beam and evaluate the capacity in generating helical waves. Corresponding experiments are also implemented to analyze the influencing factors in the structural design of the transducer. The results indicate that the pulse cycle affects the half divergence angle slightly. The compromise should be considered when designing the central angle of the transducer because it influences the signal amplitude and further imaging resolution in a contradictory way.

The Chilean Sectoral Innovation Systems: An Approach from The National Innovation Survey

This paper proposes a configuration and characterisation of the economic sectors in Chile applying Malerba’s sectoral innovation systems approach. Its objective is to examine the existence of sectoral systems of innovation in Chile and their characteristics. Using data from the Chilean Tenth Innovation Survey of Firms, a three-step statistical analysis was performed. In the first step, 15 variables were chosen and converted by factor analysis into four components reflecting the configuration of the sectoral system. In the second step, a cluster analysis was carried out to determine the characterisation of the sectors. In the final step, a simple econometric model was developed to estimate a proxy for the propensity to patent of the economic sectors. It is possible to discover the existence of three groups of sectoral innovation systems. One is characterised by a low propensity to patent. Another one uses market information and some effort in R&D to innovate. A third one is characterised by a strong use of market sources, high effort in R&D, strong networking and collaboration, and a close interaction with the industrial property system. This paper shows the usefulness of composite variables in identifying those sectors with higher propensity to patent. In particular, the factor networks and collaboration is the most important. This last is important to highlight in terms of policies in science and technology that aim to establish formal mechanisms to share common knowledge strengthening the relationships among the different players of the innovation process

Архітектоніка комплексної модернізації агрострахового ринку України в умовах трансформаційних процесів

Creating a strong agricultural insurance market in Ukraine as an effective resource and tool to strengthen the agricultural sector of the economy from the standpoint of minimizing risks affecting the profitability of production is one of the key stages in the development of the Ukrainian insurance system in the agricultural sector. However, the Ukrainian agricultural insurance market is still in its infanthood and is developing unsystematically, without a clearly defined development strategy and proper state support. The purpose of the article is to develop proposals for the architecture of complex modernization of the Ukrainian agricultural insurance market in terms of transformation processes with vector interpretation of its development. The architectonics of complex modernization of the Ukrainian agricultural insurance market in the conditions of transformation processes is offered and the expediency of its strategizing in the context of five key vectors is proved, which, in turn, compose a vector set of directions of strategic character. The author's vision of strategic vectors of complex modernization of the agricultural insurance market of Ukraine is focused on: format outlines of the market (key forms of its further development), compositional structural framework of the market (formatting within the sectoral configuration taking into account the peculiarities of each of the three sectors); in terms of formal – legal norms and rules of insurance and informal restrictions – ethical and cultural norms), innovation of agricultural insuranceactivities (new approaches to the use of agricultural insurance potential) and agricultural insurance environment (insurance environment in the agricultural sector of the economy). According to the key provisions of the strategy of development of the agricultural insurance market of Ukraine, a logical and functional approach to the architecture of modernization of the Ukrainian agricultural insurance market in the conditions of transformation processes based on the principles: efficiency, tolerance, modernity, innovation, strategizing, transparency, clientele, customer orientation format. The study contains theoretical and practical provisions that form the basis for sustainable and dynamic development of the local agricultural insurance market in terms of transformation processes.

Directionality of transitions in space: Diverging trajectories of electric mobility and autonomous driving in urban and rural settlement structures

How does the spatial context shape early innovation trajectories and how will this influence the directionality of transitions? We elaborate these questions for the case of transitions in personal mobility, focusing on emerging trajectories of electric vehicles and autonomous driving. We analyze how the dynamics depend on whether innovation and transition strategies are primarily geared towards urban or rural contexts. In order to identify potentially diverging trajectories, we specify socio-technical regime structures at two levels: the level of service regimes (i.e. rules that relate to specific means of transport, like the car) and the level of the sectoral regime (i.e. rules that regulate the interplay between the different service regimes). We will show that depending on whether the early innovation strategies are oriented at rural or urban contexts, quite different directionalities can result both regarding the technological trajectory of the new service option, but also regarding the overall sector configuration.

Annular sector elemental image array generation method for tabletop integral imaging 3D display with smooth motion parallax.

One of the important features of tabletop 3D displays is the annular viewing area above the display system. In this paper, we propose an annular sector elemental image array (ASEIA) generation method for the tabletop integral imaging 3D display to form the annular viewing zone with smooth motion parallax. The effective pixels of the elemental images are distributed as annular sector, and they are mapped from the perspective images captured by the ring-shaped camera array. Correspondingly, the viewing sub-zones can be formed with an annular sector configuration and can be seamlessly stitched by using the time division scheme. Compared with the previous approach with rectangular elemental image array (EIA) distribution, the number of viewing sub-zones is decreased from 360 to 10 for the same effect of smooth motion parallax. Meanwhile, rendering efficiency is improved. The experimental results show that the proposed method is feasible to produce 360-degree continuous viewpoints in an annular viewing zone.

Combustion Dynamics of Annular Systems

ABSTRACT New results on the dynamics of annular combustors during ignition and combustion instabilities will be reviewed. Ignition dynamics is considered first by examining experiments carried out in a system comprising a plenum feeding premixed gaseous reactants through multiple swirling injectors and an annular combustor formed by two concentric transparent quartz walls allowing full optical access to the flame. The analysis focuses on the “light-round” process during which the flame spreads from one injector to the next eventually leading to established flames on each injector. The transparent lateral walls allow a full view of the flame propagation from a spark igniter located in the neighborhood of one injector. High speed imaging is used to examine flame displacement and deduce the ignition delay yielding a full light around of the annular combustor. Changes associated to operation with spray flames are then discussed. The second part of this article is concerned with combustion instabilities of annular systems coupled by azimuthal modes. This type of oscillation has received considerable attention in recent years because the underlying coupling is often observed in the advanced premixed combustion architectures used in modern gas turbines. Recent studies have allowed a detailed examination of the dynamics of annular devices comprising multiple swirling injectors. Experiments on annular systems and single sector configurations provide new insight on the coupling process between acoustics and unsteady combustion. Results for self-sustained combustion oscillations coupled by azimuthal modes are presented for operation with gaseous premixed reactants and with spray flames.

Civil Society Regimes and School Choice Reforms: Evidence from Sweden and Milwaukee

AbstractWe examine the effects of school choice reforms implemented in the early 1990s in two different settings: Sweden and Milwaukee (WI, U.S.). We show how both the ideological and theoretical arguments for choice reform were similar in the two contexts, yet the consequences in terms of the organizational outcome and institutional sector configuration ended up strikingly dissimilar. While the new group of actors in the Swedish school system consisted primarily of large-scale for-profit schools, with only a minor share of the expansion being catered to by nonprofit actors, the Milwaukee school choice program became dominated by small-scale nonprofit schools operated by religious communities. We seek to explicate these differences by drawing on the welfare state literature and social origins theory, as well as from organizational and historical institutional theory. We argue that the resulting composition of providers is directly related to the deep-seated differences in the civil society regimes operating in the two contexts.

A Combinatorial model to optimize air traffic flow management problems

In this paper we introduce a new 0–1 mathematical formulation for the Air Traffic Flow Management problem. The model is based on a 4D-graph, which allows us to consider the problem not as general combinatorial one, but as a set of shortest path problems with common capacity constraints, a fact that introduces several neat features. Among the decisions considered in the model are ground and air delays, changes in the speed of the aircraft and alternative routes. The proposed model, in comparison with the current state of the art, is shown to be an easy way to model different real complex situations (e.g., more realistic representation of costs and decisions involved, as well as dynamic sector configuration). The rapidity with which the computations are performed in this model shows the applicability of our proposal to the industry.

A Comparative Analysis of Simulated Annealing and Variable Neighborhood Search in the ATCo Work-Shift Scheduling Problem

This paper deals with the air traffic controller (ATCo) work shift scheduling problem. This is a multi-objective optimization problem, as it involves identifying the best possible distribution of ATCo work and rest periods and positions, ATCo workload and control center changes in order to cover an airspace sector configuration, while, at the same time, complying with ATCo working conditions. We propose a three-phase problem-solving methodology based on the variable neighborhood search (VNS) to tackle this problem. The solution structure should resemble the previous template-based solution. Initial infeasible solutions are built using a template-based heuristic in Phase 1. Then, VNS is conducted in Phase 2 in order to arrive at a feasible solution. This constitutes the starting point of a new search process carried out in Phase 3 to derive an optimal solution based on a weighted sum fitness function. We analyzed the performance in the proposed methodology of VNS against simulated annealing, as well as the use of regular expressions compared with the implementation in the code to verify the feasibility of the analyzed solutions, taking into account four representative and complex instances of the problem corresponding to different airspace sectorings.

The role of inter-sectoral learning in knowledge development and diffusion: Case studies on three clean energy technologies

Studies in technological innovation systems (TIS) have made significant progress in explaining the dynamics of industry formation for emerging technologies, recognizing that learning is an interactive process. Recent literature suggests that knowledge development and diffusion among different sectors can play a role in the establishment of a TIS. However, we lack an understanding of how the characteristics of different sectors involved in a TIS influence inter-sectoral learning, i.e. purposive learning-by-interacting between different sectors involved in a TIS. To address this gap, we examine how patterns of inter-sectoral learning vary across three TISs – solar photovoltaic systems, wind turbines, and lithium-ion batteries. Using concepts from the literature on sectoral systems of innovation, we show that the characteristics of the different sectors involved in the TIS influence patterns of inter-sectoral learning. Thus, we provide a systematic way of explaining differences in the importance of learning-by-interacting between different technologies observed in the empirical literature, helping policymakers anticipate potential failures in inter-sectoral learning, and we suggest measures to address them. We also demonstrate the value of explicitly analyzing the sectoral configuration in future TIS analyses, and hence contribute to more closely integrating the literatures on TIS and sectoral systems of innovation.

Gating and Syntactical Analysis of Spatial Configuration of Sectors of Gurgaon (Gurugram), India

Gating and Syntactical Analysis of Spatial Configuration of Sectors of Gurgaon (Gurugram), India

Specialized Method of Calculating Heat Input from Wastewater in the Premises of the Sewage Pumping Stations

Modern sewage plant is a complex engineering structure with a different configuration of functional sectors (zones). The inlet sections to the pumps operate in a gravity flow mode, characterized by incomplete filling of the section with water, based on the requirements of non-absorption of ventilation safety for the resulting gas, mainly methane. As the liquid and gas have a higher temperature than the air temperature in the premises of the pumping stations. The problem of heat flow from the fluid have to be solved by a specially designed method that takes into account the separation of gas and liquid flows in pipes and rectangular channels by applying the theory of similarity, criteria equations and computational experiment. An important circumstance in the structure of the algorithm of the calculation is finding and using the concept of the wetted perimeter, as well as newly introduced in the article the concept of the average heat transfer coefficient with respect to the specific configuration of each element partially filled with liquid. Pumps and pipes after them as usual completely filled with water, but here in turn, we have to consider a special form of surfaces of equipment and fittings drainage systems.