Open Sector Research Articles

Finite-time output feedback control for a class of stochastic low-order nonlinear systems with output function

This paper studies the problem of finite-time output feedback stabilisation for a class of stochastic low-order nonlinear systems with output function. Under the assumption that output function is continuous, by generalising the adding a power integrator technique, constructing a new implementable reduced-order observer and using the stochastic finite-time stability criterion, the maximal open sector Ω of output function is given. As long as output function belongs to any closed sector included in Ω, an output feedback controller can be developed to guarantee finite-time stability in probability of the closed-loop system. A simulation example is provided to verify the effectiveness of the proposed design method.

Numerical modelling of the pit wall stability while optimizing its boundaries to ensure the ore mining completeness

Purpose is to assess changes in the stress-strain state of walls along the whole periphery of a super-deep open pit while optimizing its current and final boundaries for the complete ore excavation. Methods. Finite element 3D analysis of stress-strain state (SSS) of the soil and rock mass relies upon the models varying in their scales. Macrolevel model includes the full pit helping perform initial evaluation of its stability depending upon changes in the general wall slope along the pit periphery. Then, the macromodel is separated into sectoral models with smaller scales oriented radially in such a way to include potentially unstable wall areas. The sectoral models make it possible to show the complex bench line in more detail after the peripheries were optimized in terms of economic factor and simulate layered structure of the rock mass. Elastoplastic model of the medium as well as Mohr-Coulomb strength criterion has been implemented using RS3 (Rocscience) program codes. Findings. An indicator of wall strength (safety factor) distribution along the pit periphery has been identified; potential sliding surfaces within each of the separated open pit sectors have been localized based upon the shear strength reduction (SSR) procedure. Influence by the general wall slope as well as by the indicator of the ore excavation completeness on the stripping ratio has been demonstrated. Originality. For the first time, two-level modelling has shown difference in a safety factor depending upon a model scale and a reflection degree of the soil-rock mass structure. In the context of the actual mining and geological conditions of Kacharsky open pit, changes in the safety factor along the pit periphery have been identified depending on the general slope of the wall. Practical implications. Based upon the pit wall stability along the whole periphery, the possibility has been substantiated to optimize its design boundaries for the excavation of those amenable ore reserves, occurred near them, inclusive of ore, occurring in a bottom, which mining is impossible due to inaccessibility.

Output feedback stabilization of stochastic high‐order nonlinear time‐delay systems with unknown output function

AbstractThis article considers the problem of output feedback stabilization for a class of stochastic high‐order nonlinear time‐delay systems with unknown output function. For stochastic high‐order nonlinear time‐delay systems, based on the Lyapunov stability theorem, by combining the addition of one power integrator and homogeneous domination method, the maximal open sector of output function is given. As long as output function belongs to any closed sector included in , an output feedback controller can be developed to guarantee the closed‐loop system globally asymptotically stable in probability.

Distinct PM2.5‐Related Near‐Term Climate Penalties Induced by Different Clean Air Measures in China

AbstractThe reductions in aerosols often exacerbate climate warming. It remains unclear how to effectively alleviate PM2.5 pollution while minimizing the penalty on climate warming. Here we identify the clean air measures in China that are associated with low aerosol climate penalty efficiency (ACPE), which is defined as aerosol radiative forcing per unit PM2.5 concentration reduction. The measures in transportation, residential combustion, and open burning sectors generally caused lower ACPE [0.07, 0.24, and 0.10 (W m−2)/(μg m−3)] than those from other sectors [0.34–0.46 (W m−2)/(μg m−3)]. This is ascribed to relatively small decreases in cloud concentration nuclei per unit PM2.5 reduction in these sectors, which is further attributed to either relatively low aerosol hygroscopicity or relatively small decrease in aerosol number. Most measures in the former three sectors have low ACPE of <0.15 [(W m−2)/(μg m−3)] and thus may be prioritized for synergistically controlling PM2.5 pollution and climate warming.

Inflationary α-attractor from type-IIB/F theory

We derive an potential of slow-roll inflation in the warped D brane set-up featuring three intersecting D7 branes under type of CY 3-compactification within type-IIB/F theory with some near-conifold regions. The underlying quadratic structure of the kinetic poles is found to arise from a correction in the Kähler potential when an extra contribution of open string moduli is turned on. While the closed string sector of the moduli spectrum is completely stabilized via quantum corrections of perturbative and non-perturbative origin, the open string sector plays the lead role in driving the inflationary expansion in the radial direction. A generic asymptotic behaviour of the inflaton field near the pole boundaries manifests itself as the slow-roll plateau in canonical field space, which becomes responsible for giving universal predictions of the cosmological parameters. We find that the presence of the open strings near conifold regions brings the realization of pole inflation in the present set-up. Finally we compare our results with similar models and discuss the importance of exploring precise values of α in the light of ongoing and forthcoming cosmological surveys.

Klasterisasi Perusahaan Sektor Energi Berdasarkan Rasio Kinerja Keuangan dengan Metode Fuzzy C-Means

The increasing number of companies on the Indonesia Stock Exchange means that there are more investment options for investors, causing investors to be confused about choosing the right company to invest in. Investors need to avoid mistakes in investing, one of which is by analyzing the company's financial performance ratios. In this study, companies in the open energy sector will be grouped based on financial performance ratios using the Fuzzy C-Means method. The results of this clustering can be used as material for consideration for investors wishing to invest in the open energy sector. The Fuzzy C-Means method is a method for grouping objects where the presence of cluster members is based on the degree of fuzzy membership. The ratios to be used are Earning per Share (EPS), Price Earning Ratio (PER), Return on Assets (ROA), Return on Equity (ROE), and Net Profit Margin (NPM). The number of clusters to be formed is 2 clusters. The calculation results obtained are that there are 46 companies in Cluster 1 and 22 companies in Cluster 2. Based on the analysis of cluster characteristics, cluster 2 is a cluster that contains companies with high financial ratios with the highest ratio value being Earning per share and net profit margin This means that the financial performance of companies in this cluster is quite good.

Burns space and holography

We elaborate on various aspects of our top-down celestial holographic duality wherein the semiclassical bulk spacetime is a 4d asymptotically flat, self-dual Kähler geometry known as Burns space. The bulk theory includes an open string sector comprising a 4d WZW model and a closed string sector called “Mabuchi gravity” capturing fluctuations of the Kähler potential. Starting with the type I topological B-model on the twistor space of flat space, we obtain the twistor space of Burns space from the backreaction of a stack of N coincident D1 branes, while the chiral algebra is obtained from (a twist of) the brane worldvolume theory. One striking consequence of this duality is that all loop-level scattering amplitudes of the theory on Burns space can be expressed as correlation functions of an explicit 2d chiral algebra.We also present additional large-N checks, matching several 2 and 3-point amplitudes and their collinear expansions in the WZW4 sector, and the mixed WZW4-Mabuchi sector, of the bulk theory to the corresponding 2 and 3-point vacuum correlators and operator product expansions in the dual chiral algebra. Key features of the duality, along with our main results, are summarized in the introduction.

The interdependencies between the private and public sectors in open economies

Empirical evidence shows that countries with larger public sectors also have larger trade shares and a larger share of firms that export. These links between the public and the private sector are reconciled in an analytically tractable general equilibrium model allowing for a two-way causal relation between size (and the composition) of the public sector and openness and industry structure of the private sector. First, a larger public sector or a larger share of public expenditure used for public employment (alternative to transfers) results in a more open private sector (trade share and fraction of firms exporting), and it is also associated with more fat-tailedness of the firm size distribution, higher average productivity, lower average unit labour costs, and better wage competitiveness and terms of trade. These outcomes are driven by endogenous entry and selection of firms. Second, for optimal fiscal policies, international spillovers imply that non-cooperative policies have an upward bias in the overall size of the public sector, but a downward bias in transfers as a share of public expenditures. Trade liberalization and the degree of firm heterogeneity magnify these biases and thereby influence the size and structure of public expenditures.

Economic openness, financial bias, and the urban–rural income gap

AbstractWe develop a theoretical model to analyze the impact of economic openness and financial bias (i.e., open sector bias and urban area bias) on the urban–rural income gap. Our theoretical model puts forth three propositions, which we empirically test using a dynamic panel data model. We use data from 30 provinces in China spanning from 2004 to 2017 for our empirical analysis. Our results reveal a U‐shaped relationship between the urban–rural income gap and the level of regional economic openness. We also find an inverted U‐shaped relationship between the urban–rural income gap and the open sector bias of regional financial development. Moreover, our analysis indicates a positive relationship between the urban–rural income gap and urban area bias in regional financial development. These three propositions hold true for both nominal and real measures of the income gap.

Open-closed string field theory in the large N limit

We use the new nilpotent formulation of open-closed string field theory to explore the limit where the number N of identical D-branes of the starting background is large. By reformulating the theory in terms of the ’t Hooft coupling λ := κN, where κ is the string coupling constant, we explicitly see that at large N only genus zero vertices with arbitrary number of boundaries survive. After discussing the homotopy structure of the obtained large N open-closed theory we discuss the possibility of integrating out the open string sector with a quantum but planar homotopy transfer. As a result we end up with a classical closed string field theory, described by a weak L∞-algebra containing a tree-level tadpole which, to first order in λ, is given by the initial boundary state. We discuss the possibility of removing the tadpole with a closed string vacuum shift solution, to end up with a new classical closed string background, where the initial D-branes have been turned into pure closed-string backreaction.

Open strings in IIB orientifold reductions

We consider type IIB compactifications on a general 4D group manifold with different types of possible spacetime filling O-planes and the corresponding D-branes parallel to them. Once fluxes allowed by the associated orientifold projection are included, a 6D \U0001d4a9 = (1, 1) gauged supergravity is obtained. In this paper we show how the consistent coupling to dynamical open strings living on the spacetime filling D-branes may be captured by the inclusion of extra vector multiplets and extra embedding tensor deformations on the gauged supergravity side. As a result, the quadratic constraints on the embedding tensor consistently reproduce the source corrected 10D Bianchi identities. Furthermore, the field strength modifications induced by the open string sector could potentially be understood as U-dual versions of the Green-Schwarz terms. Finally, the entire scalar potential of the theory exactly matches the one obtained from reduction of the bulk action plus the source contributions.

Sediment resuspension and transport processes during dense water cascading events along the continental margin of the southern Adriatic Sea (Mediterranean Sea)

The near-bottom nepheloid layer in the western margin of the Southern Adriatic Sea was monitored for 8-years by measurements acquired at two mooring sites. The two moorings, equipped with CTD probes and ADCPs, are located in the Bari Canyon and in an open slope sector along the Southern Adriatic Margin. These regions are of interest because affected by episodic dense shelf water cascading events whose dynamic has direct implications on deepwater morpho-dynamic, biogeochemical cycles and trophic networks. In this work, the sedimentation flux and its interdecadal dynamic is analysed examining in detail the sedimentary processes triggered by dense water flow through the analysis of the echo records of ADCPs.The integration of hydrodynamic, turbidity and particle grain-size data provided estimates of the sediment flux, separating phases when the flow actively erodes the seabed from phases when particles are transported to the mooring location through density flows.The frequency and velocity of dense-water cascading currents vary in time and space reflecting the capacity of sediment transport. Data analysis demonstrated that the hydrodynamic event that mostly accounts for sediment transfer to the deep basin is represented by current pulses induced by the passage of dense waters. The average annual sediment flux has been quantified and the Bari canyon shows transport more than five time larger than in the open slope sector, confirming that the canyon is the dominant pathway of sediment transfer to the deep basin. In contrast, in the open slope, albeit a minor lateral sediment advection, is impacted by currents that are able to trigger intense resuspension of seabed sediments, which can contribute over 80% of the total solid load.This study allows unravelling the role of cascading in the sediment resuspension and transport processes and is essential to support deciphering the sedimentary records in the study area. The long temporal extent of the dataset used for quantification provides a reliable contribution to the Quaternary sediment budget determination.

Antenna source of radio-frequency emission in ion-proton pulsars

ABSTRACT The growth of a longitudinal or quasi-longitudinal Langmuir mode in the outward-moving beam of ions and protons that forms the open sector of an ion-proton pulsar magnetosphere radiates as an analogue of an end-fed high-impedance horizontal straight-wire antenna an integral number of half-waves in length. The radiation has, broadly, the energy flux, linear polarization, and spectral index that are widely observed: also, the notch phenomenon seen in some integrated pulse profiles occurs naturally. The new field of pulsar observations below 100 MHz may lead to productive tests of the radio emission mechanism.

THE URGENCY OF FOREIGN DIRECT INVESTMENT IN MICRO, SMALL, AND MEDIUM ENTERPRISES FINANCING FRAMEWORK: THE CASE OF INDONESIA

This research aims to check whether the rate of production growth in the MSME sectors open to foreign direct investment (FDI) was lower than in the closed MSME sectors before the policy in 2016 and whether the growth rate of the open MSME sectors’ production lower than the closed MSME sectors after the policy in 2016. The study covers a period of 9 years from 2011 to 2020 based on the data from Indonesian Statistics Bureau. Data used was industrial sectors’ performance, classified into closed and open for FDI sectors. The classification is defined based on Presidential Regulation No. 44 of 2016. In total there are 13 closed and 10 open sectors. We analyse the data using t-test analysis between closed and open FDI industrial sectors. The results of the study found that the performance of open MSMEs was significantly lower than the performance of closed MSMEs, both before and after the liberalization. Therefore, the government must relax the requirements given to investors to invest in open MSMEs.

Stranded assets and early closures in global coal mining under 1.5∘C

With the Glasgow Climate Pact 2021, the global community has committed explicitly to phasing down coal consumption. Yet the coal supply sector continues to develop new capacities, despite the risk of asset stranding. This article presents the first assessment of the implications of 1.5∘C mitigation pathways for the coal mining industry. Based on open coal mine data and a new version of the open coal sector model COALMOD-World, the prospects for individual coal mining regions and their risk of early mine closures and asset stranding are analyzed. Results show that global cumulative production capacity from operating thermal coal mines exceed the remaining consumption values for 2020 through 2050 by more than 50%. This supply-consumption discrepancy would hit Russia and the USA especially hard, causing the stranding of around 80% of operating capacities in each case. But the early closure of operating coal mines would affect all of the world’s major thermal coal producing regions, with most regions seeing more than three-fourths of their mine capacity closing early by 2030. Stranded assets from operating coal mines would total some USD2015 120 to 150 billion until 2050, with an additional USD2015 100 billion should currently proposed new coal mining projects be realized. If demand declines in accordance with 1.5∘C pathways, new coal mines or mine extensions would be redundant in all coal regions. Although the stranded asset value of mines is relatively small compared to that of the coal power plant sector, early closures would especially affect workers and local communities. Thus, efforts are urgently needed to ensure a just transition in coal mining regions and to address excess operating and proposed coal supply capacities that continue to fuel global warming.

Support for small businesses amid COVID‐19

AbstractHow should the government support small and medium‐sized enterprises amid a pandemic crisis while balancing the trade‐off between short‐run stabilization and long‐run allocative efficiency? We develop a two‐sector equilibrium model featuring small businesses with private information on their likely future success and a screening contract. Businesses in the sector adversely affected by a pandemic can apply for government loans to stay afloat. A pro‐allocation government sets a harsh default sanction to deter entrepreneurs with poorer projects, thereby improving long‐run productivity at the cost of persistent unemployment, whereas a pro‐stabilization government sets a lenient default sanction. Interest rate effective lower bound leads to involuntary unemployment in the other open sector and shifts the optimal default sanction to a lenient stance. The rise in firm markups exerts the opposite effect. A high creative destruction wedge polarizes the government's hawkish and dovish stances, and optimal default sanction is more lenient, exacerbating resource misallocation. The model illuminates how credit guarantees might be structured in future crises.

Bibliometric Exploration into the Global Research Impact of China’s Thousand Talents Brand

The Thousand Talents Plan was an ambitious government initiative to repatriate and/or recruit experts from the global Chinese diaspora, along with some non-Chinese experts, with generous research funding and relocation packages. The plan has received much criticism from abroad, accusing endeavors of taking advantage of the open international education sector and facilitating espionage. While the Thousand Talents Plan received much of the attention, there are reportedly over 200 talent recruitment plans implemented by the Chinese government. We refer to these Talents Plans broadly as the Thousand Talents Brand (TTB), due to the diverse subjects, various programs, and a disparate number of the plans. Given the scrutiny and haphazardness of these initiatives, it has been difficult to gauge the impact on the global landscape of higher education, as official data on the broader project has not been readily available. Using bibliometric analysis of Web of Science, we find that research with funding from the TTB did decrease following the recent outcry, but was only roughly 1% of all Chinese research output at its peak in 2018. We find that the research was mostly concentrated in the hard sciences, with relatively little in the social sciences. Our results show the research funded through the initiatives was most commonly partnered with researchers in the Western powers, such as the US, Germany, and England, including connections to institutions with national security concerns like the US Department of Energy. While the findings do illustrate a complex web of global research governance through international partnerships, they cannot alleviate concerns that the TTB programs are potentially malign to sensitive sectors.

A Review on Media Tradition and Realities in Natural Disasters

The paper surveys how the media has added to battling normal perils. An essential goal of the examination is to centre the associations, pressures and territories of bargains of media amid common fiascos highlighted inside the late writing. The article focuses on three areas: (1) media response to routine disasters; (2) media fallacies about disaster casualties; and (3) media role as a partner or weight group in routine disasters. Focusing on these three angles, the available material reveals that the media coverage of disaster events has a lasting impact on the minds and spirits of the populace and may effectively urge people to assist or can result in feedback of the situation. The media occasionally plays a significant role in spreading false beliefs about disaster victims, characterising them as either defenceless or raiders. Since they are there to gather direct and limited catastrophe data as an aware to provide in the open commercial sector of a group of observers, the media may give weight to their reports rather than spare or save casualties and survivors.

A Review on Media Tradition and Realities in Natural Disasters

The paper surveys how the media has added to battling normal perils. An essential goal of the examination is to centre the associations, pressures and territories of bargains of media amid common fiascos highlighted inside the late writing. The article focuses on three areas: (1) media response to routine disasters; (2) media fallacies about disaster casualties; and (3) media role as a partner or weight group in routine disasters. Focusing on these three angles, the available material reveals that the media coverage of disaster events has a lasting impact on the minds and spirits of the populace and may effectively urge people to assist or can result in feedback of the situation. The media occasionally plays a significant role in spreading false beliefs about disaster victims, characterising them as either defenceless or raiders. Since they are there to gather direct and limited catastrophe data as an aware to provide in the open commercial sector of a group of observers, the media may give weight to their reports rather than spare or save casualties and survivors.

Möbius metric in sector domains

The Möbius metric δG is studied in the cases, where its domain G is an open sector of the complex plane. We introduce upper and lower bounds for this metric in terms of the hyperbolic metric and the angle of the sector, and then use these results to find bounds for the distortion of the Möbius metric under quasiregular mappings defined in sector domains. Furthermore, we numerically study the Möbius metric and its connection to the hyperbolic metric in polygon domains.