Proper Space Research Articles

The VVV open cluster project. Near-infrared sequences of NGC 6067, NGC 6259, NGC 4815, Pismis 18, Trumpler 23, and Trumpler 20

ABSTRACT Open clusters are central elements of our understanding of the Galactic disc evolution, as an accurate determination of their parameters leads to an unbiased picture of our Galaxy’s structure. Extending the analysis towards fainter magnitudes in cluster sequences has a significant impact on the derived fundamental parameters, such as extinction and total mass. We perform a homogeneous analysis of six open stellar clusters in the Galactic disc using kinematic and photometric information from the Gaia DR2 and VVV surveys: NGC 6067, NGC 6259, NGC 4815, Pismis 18, Trumpler 23, and Trumpler 20. We implement two coarse-to-fine characterization methods: first, we employ Gaussian mixture models to tag fields around each open cluster in the proper motion space, and then we apply an unsupervised machine learning method to make the membership assignment to each cluster. For the studied clusters, with ages in the ∼120–1900 Myr range, we report an increase of ∼45 per cent new member candidates on average in our sample. The data-driven selection approach of cluster members makes our catalogue a valuable resource for testing stellar evolutionary models and for assessing the cluster low-to-intermediate mass populations. This study is the first of a series intended to homogeneously reveal open cluster near-infrared sequences.

THE FORMATION OF FISCAL SPACE WHILE OVERCOMING VACCINE NATIONALISM AND ENSURING SUSTAINABILITY OF DEVELOPMENT

Introduction. The COVID-19 pandemic has caused the worst global economic and social crisis in recent decades. In such circumstances, the global community has been developing and taking measures to overcome the pandemic, one of which should be a rapid and unprecedented by scale vaccination of the population. Problem Statement. Under conditions of intensive spread of the coronavirus infection, vaccination can halt it and become a factor of gradual economic recovery. Purpose. Analysis of the preconditions and features of the development of fiscal space to ensure vaccination against COVID-19 in Ukraine, as one of the most important factors of this country’s economic recovery in the current conditions of the global vaccine market. Materials and Methods. Comparative analysis and theoretical generalization of developments and trends in the global market of vaccines against COVID-19 in current scholarly research and practical publications, as well as analysis of official statistics and analytical materials of the State Statistics Service of Ukraine, the United Nations, the World Health Organization. Results. The authors have identified the current trends in the global market of vaccines against COVID-19, which have signs of fierce competition in conditions of insufficient production capacity and shortage of vaccines. The research has shown the contradictions between the emergence of the vaccine’s status of a global public good and the vaccine nationalism. The authors have assessed the needs to expand Ukraine’s fiscal space in order to carry out a successful vaccination of this country’s population against COVID-19 in various alternative scenarios, with due consideration of the priorities of the coverage of particular population groups. Conclusions. Creating a proper fiscal space for vaccination is one of the central elements of the fight against COVID-19. Such a vaccination would allow carrying out a gradual phased preventive immunization, breaking the chain of contagion, and attaining an economic recovery without repeated lockdowns.

Dynamics on the Morse boundary

Let X be a proper geodesic metric space and let G be a group of isometries of X which acts geometrically. Cordes constructed the Morse boundary of X which generalizes the contracting boundary for CAT(0) spaces and the visual boundary for hyperbolic spaces. We characterize Morse elements in G by their fixed points on the Morse boundary $$\partial _MX$$ . The dynamics on the Morse boundary is very similar to that of a $$\delta $$ -hyperbolic space. In particular, we show that the action of G on $$\partial _MX$$ is minimal if G is not virtually cyclic. We also get a uniform convergence result on the Morse boundary which gives us a weak north-south dynamics for a Morse isometry. This generalizes the work of Murray in the case of the contracting boundary of a CAT(0) space.

Numerical Study of Supersonic Mixed Compression Air Intake With an Array of Air Jets

Abstract Computational study of flow physics inside the mixed compression air intake has been carried out with and without air jets (AJs) at design Mach number of 2.2. Reynolds-averaged Navier–Stokes (RANS) equations were solved with k–ω turbulence model by using commercially available software ansys. The scope of this research is to improve the flow field inside the air intake and efficiency of supersonic air intake by implementing AJs on the ramp surface. An array of AJs containing two, four, and five AJ holes, respectively, of 1 mm each has been made on the ramp surface perpendicular to the flow with equal spacing between them. The injection pressure through AJ has been kept constant for all the cases. Flow distortion (FD) and total pressure recovery (TPR) were selected to measure the performance of air intake. All the simulations have been performed at a back-pressure ratio of 6. The results obtained suggest that implementation of proper spacing between AJs can improve the performance of air intake due to the mixing of vortices generated by AJs with freestream flow. It is revealed that an array of AJs containing four holes on ramp surface works best and helps in controlling the shock-induced separation.

α-MnO2 nanotube@δ-MnO2 nanoflake hierarchical structure on three-dimensional graphene foam as a lightweight and free-standing supercapacitor electrode

Three-dimensional graphene foam (3D GF) is one of the promising candidates due to its fascinating characteristics. In the paper, we reported a simple hydrothermal method to fabricate hierarchical α-MnO2 nanotube@δ-MnO2 nanoflake on GF (GF@MNT@MNF) as a lightweight and free-standing electrode of supercapacitor. The 3D GF could serve as an ideal supporter to grow MnO2 active material, and MnO2 mass percentage affects significantly on the electrochemical properties of the composite electrode. When the mass percentage of MnO2 is 60%, a maximum specific capacitance of 202 F·g−1 with respect to the entire electrode and 336 F·g−1 relative to active material is achieved. The GF@MNT@MNF electrode presents a remarkable cyclic stability (maintaining about 97% of original capacitance over 5000 cycles). The excellent electrochemical performance of the GF@MNT@MNF electrode is resulted from the combination of the lightweight, flexible, conductive GFs and MnO2 hierarchical structure with large contacting interface and proper space distribution. Furthermore, an asymmetric supercapacitor based on GF@MNT@MNF composites was assembled, which showed a great energy density of 23.2 Wh·kg−1 under a power density of 119.9 W·kg −1 in wide potential range of 0–1.8 V. The research may provide a method for lightweight, free-standing and high-performance electrode material for efficient and convenient energy storage device.

A Unified Collaborative Representation Learning for Neural-Network Based Recommender Systems

With the boosting of neural networks, recommendation methods become significantly improved by their powerful ability of prediction and inference. Existing neural-network based recommender systems (NN-RSs) usually first employ matrix embedding (ME) as a pre-process to learn users’ and items’ representations (latent vectors), then input these representations to a specific modified neural network framework to make accurate Top-k recommendations. Obviously, the performance of ME has a significant effect on RS models. However, most NN-RSs focus on accuracy by building representations from the direct user-item interactions (e.g., user-item rating matrix), while ignoring the underlying relatedness between users and items (e.g., users who rate the same ratings for the same items should be embedded into similar representations), which is an ideological disadvantage. On the other hand, ME models directly employ inner products as a default loss function metric that cannot project users and items into a proper latent space, which is a methodological disadvantage. In this paper, we propose a supervised collaborative representation learning model - Magnetic Metric Learning (MML) - to map users and items into a unified latent vector space, enhancing the representation learning for NN-RSs. First, MML utilizes dual triplets to model not only the observed relationships between users and items, but also the underlying relationships between users as well as items to overcome the ideological disadvantage. Specifically, a modified metric-based dual loss function is proposed in MML to gather similar entities and disperse the dissimilar ones. With MML, we can easily compare all the relationships (user to user, item to item, user to item) according to the weighted metric, which overcomes the methodological disadvantage. We conduct extensive experiments on four real-world datasets with large item space. The results demonstrate that MML can learn a proper unified latent space for representations from the user-item matrix with high accuracy and effectiveness, and lead to a performance gain over the state-of-the-art RS models by an average of 17 percent.

Sounding out the repowering potential of wind energy – A scenario-based assessment from Germany

Wind energy in Germany is awarded a crucial role in increasing the share of renewable energies in the electricity mix to 65% until 2030, especially in light of the federal government’s recent decision to phase out coal-based electricity until 2038. In addition to the targeted expansion of wind energy, Germany will be struggling with thousands of wind turbines at the end of their service life in the next years. To advance the expansion of wind energy and to increase its efficiency, repowering is deemed a promising way to deal with the upcoming changes in wind energy use. This study assesses Germany’s repowering potential in 2021–2040. It estimates how many of the existing wind turbine sites in Germany can be used for repowering without violating recently recast geographical restrictions while at the same time meeting proper spacing criteria for repowered wind turbines. The results from fifteen scenarios indicate the repowering potential in Germany to be highly impacted by the recast geographical restrictions and wind turbine categories used to repower. Compared to the energy contributed by onshore wind in the baseline year 2021, the best-case scenario could provide 110%. In contrast, the worst-case scenario could provide 40% of potential wind energy generation in 2040. The highest potential wind energy generation is reached under low distance restrictions of 500 m to surrounding settlement areas. The results indicate repowering alone to be unable to substantially increase the share of wind energy in Germany’s energy mix over the next two decades. Without expansion, the contribution of wind energy to Germany’s energy mix will diminish. However, despite the growing number of old wind turbines in Germany, repowering still offers more efficient exploitation of the wind resource.

Differential Polynomial Identities of Upper Triangular Matrices Under the Action of the Two-Dimensional Metabelian Lie Algebra

We study the differential polynomial identities of the algebra UTm(F) under the derivation action of the two dimensional metabelian Lie algebra, obtaining a generating set of the TL-ideal they constitute. Then we determine the Sn-structure of their proper multilinear spaces and, for the minimal cases m = 2, 3, their exact differential codimension sequence.

Long-time behavior of solutions for a fractional diffusion problem

This paper deals with the asymptotic behavior of solutions to the initial-boundary value problem of the following fractional p-Kirchhoff equation: ut+M([u]s,pp)(−Δ)psu+f(x,u)=g(x)in Ω×(0,∞),\\documentclass[12pt]{minimal}\t\t\t\t\\usepackage{amsmath}\t\t\t\t\\usepackage{wasysym}\t\t\t\t\\usepackage{amsfonts}\t\t\t\t\\usepackage{amssymb}\t\t\t\t\\usepackage{amsbsy}\t\t\t\t\\usepackage{mathrsfs}\t\t\t\t\\usepackage{upgreek}\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\t\t\t\t\\begin{document}$$ u_{t}+M\\bigl([u]_{s,p}^{p}\\bigr) (-\\Delta )_{p}^{s}u+f(x,u)=g(x)\\quad \\text{in } \\Omega \\times (0, \\infty ), $$\\end{document} where Omega subset mathbb{R}^{N} is a bounded domain with Lipschitz boundary, N>ps, 0< s<1<p, M:[0,infty )rightarrow [0,infty ) is a nondecreasing continuous function, [u]_{s,p} is the Gagliardo seminorm of u, f:Omega times mathbb{R}rightarrow mathbb{R} and gin L^{2}(Omega ). With general assumptions on f and g, we prove the existence of global attractors in proper spaces. Then, we show that the fractal dimensional of global attractors is infinite provided some conditions are satisfied.

Bargmann invariants, geometric phases and recursive parametrization with Majorana fermions

A generalized connection between the quantum mechanical Bargmann invariants and the geometric phases was established for the Dirac fermions. We extend that formalism for the Majorana fermions by defining proper quantum mechanical ray and Hilbert spaces. We then relate both the Dirac and Majorana type Bargmann invariants to the rephasing invariant measures of CP violation with the Majorana neutrinos, assuming that the neutrinos have lepton number violating Majorana masses. We then generalize the recursive parametrization for studying any unitary matrices to include the Majorana fermions, which could be useful for studying the neutrino mixing matrix.

The Structure and Operating Mechanisms of Chinese Society with Rule of Law

“Society with rule of law” is a concept strongly marked by the distinctive features of Chinese practice. It refers to the introduction of “rule of law” in the life of society over and above the operating system of public power. Like a country with rule of law and a government with rule of law, a society with rule of law has its own independent sphere, constituting the “one body, two wings” of Chinese rule of law. The concrete context of a country’s ability to mobilize, its existing legal system, the foundation of social governance, the state of social contradictions, etc., may encourage or limit the construction of a society with rule of law. Such construction should have strongly identifiable target guidelines: it should guide orderly public participation in the governance of society, maintain good order in material and cultural life, calibrate supply and demand for basic public services, and define the proper space for the activities of social organizations. The community level is the main field for the construction of a society with rule of law. We should confront grassroots constraints, focus on the main business of grassroots society, and make full use of the function of grassroots social organizations. At the same time, we should effectively integrate the important roles of government, social organizations, enterprises, lawyers and other players in the construction of a society with rule of law.

Area minimizing surfaces of bounded genus in metric spaces

AbstractThe Plateau–Douglas problem asks to find an area minimizing surface of fixed or bounded genus spanning a given finite collection of Jordan curves in Euclidean space. In the present paper we solve this problem in the setting of proper metric spaces admitting a local quadratic isoperimetric inequality for curves. We moreover obtain continuity up to the boundary and interior Hölder regularity of solutions. Our results generalize corresponding results of Jost and Tomi-Tromba from the setting of Riemannian manifolds to that of proper metric spaces with a local quadratic isoperimetric inequality. The special case of a disc-type surface spanning a single Jordan curve corresponds to the classical problem of Plateau, in proper metric spaces recently solved by Lytchak and the second author.

Preconditioned Douglas-Rachford type primal-dual method for solving composite monotone inclusion problems with applications

<p style='text-indent:20px;'>This paper is concerned with the monotone inclusion involving the sum of a finite number of maximally monotone operators and the parallel sum of two maximally monotone operators with bounded linear operators. To solve this monotone inclusion, we first transform it into the formulation of the sum of three maximally monotone operators in a proper product space. Then we derive two efficient iterative algorithms, which combine the partial inverse method with the preconditioned Douglas-Rachford splitting algorithm and the preconditioned proximal point algorithm. Furthermore, we develop an iterative algorithm, which relies on the preconditioned Douglas-Rachford splitting algorithm without using the partial inverse method. We carefully analyze the theoretical convergence of the proposed algorithms. Finally, in order to demonstrate the effectiveness and efficiency of these algorithms, we conduct numerical experiments on a novel image denoising model for salt-and-pepper noise removal. Numerical results show the good performance of the proposed algorithms.

Biohole Effectiveness Analysis through the Distribution Patternof Microbes at Each Depth in Real Time on Inseptisol SoilWith Digital Biosoildam Technology

This research was conducted on inseptisol soils, especially for plantations, with the aim of not only restoring the health and fertility of the soil due to the use of chemical fertilizers and pesticides as well as seeing the pattern of EC distribution at each depth from the center of the biohole based on the time of observation. Through controlled microbial activity, its spread through two types of biohole, namely horizontal and vertical biohole. This research observes in real time through soil parameter sensors connected to the micro controller to changes in soil acidity, infiltration rate, conductivity electrolyte level and porosity level through soil infiltration rate. Through simulations with 2 types of biohole, it can be seen the increase in EC in each depth to the time of observation in real time. From the observations of graphs and EC standards, it can be seen that the ability of the soil to provide nutrients in the root growth zone to support the schedule and distribution patterns of planting both during vegetative growth and generative growth periods. So that we will know the proper biohole distance and spacing in order to be able to provide vegetative and generative mass nutrition based on nutrient values monitored through sensors that change the analogue parameters in the micro possessor into digital information transmitted by Wi-Fi in real time. Inseptisol soils fertility simulation based on the number of microbial populations=108/cfu with variable 1: The effective depth for providing root nutrition to a depth of 30 cm with a soil fertility value or Electrolyte Conductivity/ EC 1000 uS/cm to 1900 uS/cm is reached on the 10 to 60th day. Variable 2: The effective depth for providing root nutrition is up to a depth of 24 cm with a soil fertility value or Electrolyte Conductivity/EC 1000 uS/cm to 2350 uS/cm achieved on the 10th to 60th day.

A Meta-Analysis of Postpartum Copper IUD Continuation Rates in Low- and Middle-Income Countries

Long-acting reversible contraception (LARC) initiated immediately postpartum can reduce unintended or mistimed pregnancies, and contribute to proper pregnancy spacing. Data on use and continuation of postpartum LARC in low- and middle-income countries (LMIC) is limited.We searched PubMed, OVID, Embase, Google Scholar, Cochrane, POPLINE, Global Health (CABI), and LILACS databases for relevant terms. Studies of any design, published in English, were screened for relevance based on six-month continuation rates of postpartum LARC, location of study, and LARC insertion within 48 hours after vaginal or cesarean birth. We found no relevant studies of implant or hormonal intrauterine device (IUD). Therefore, analysis was limited to studies of the copper IUD only. Two authors used the Cochrane Public Health Group Data Extraction and Assessment Template to guide data extraction to estimate pooled six-month continuation rates, and the Cochrane Risk of Bias Tool for Randomized Controlled Trials and the National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies to rate the quality of the studies. A random-effects meta-analysis of proportions was performed.Immediate-postpartum copper IUDs have a six-month continuation rate of 87% (95% CI 80-92%) in LMIC. The pooled estimated rates of six-month adverse outcomes were 6% (95% CI 5-9%) for expulsion, 5% (95% CI 4-7%) for removal, and 0.2% (95% CI 0.0-0.9%) for infection.High six-month continuation rates and a low rate of adverse outcomes suggest immediate postpartum copper IUD insertion is a feasible and acceptable postpartum contraceptive option for women living in LMIC.

Escape from mitotic catastrophe by actin-dependent nuclear displacement in fission yeast

SummaryEukaryotic cells position the nucleus within the proper intracellular space, thereby safeguarding a variety of cellular processes. In fission yeast, the interphase nucleus is placed in the cell middle in a microtubule-dependent manner. By contrast, how the mitotic nucleus is positioned remains elusive. Here we show that several cell-cycle mutants that arrest in mitosis all displace the nucleus toward one end of the cell. Intriguingly, the actin cytoskeleton is responsible for nuclear movement. Time-lapse live imaging indicates that mitosis-specific F-actin cables possibly push the nucleus through direct interaction with the nuclear envelope, and subsequently actomyosin ring constriction further shifts the nucleus away from the center. This nuclear movement is beneficial, because if the nuclei were retained in the center, unseparated chromosomes would be intersected by the contractile actin ring and the septum, imposing the lethal cut phenotype. Thus, fission yeast escapes from mitotic catastrophe by means of actin-dependent nuclear movement.

Biohole Effectiveness Analysis through the Distribution Pattern of Microbes at Each Depth in Real Time on humus Soil Integrated Smartfarming

This research was conducted on inseptisol soils, especially for plantations, with the aim of not only restoring the health and fertility of the soil due to the use of chemical fertilizers and pesticides as well as seeing the pattern of EC distribution at each depth from the center of the biohole based on the time of observation. Through controlled microbial activity, its spread through two types of biohole, namely horizontal and vertical biohole. This research observes in real time through soil parameter sensors connected to the micro controller to changes in soil acidity, infiltration rate, conductivity electrolyte level and porosity level through soil infiltration rate. Through simulations with 2 types of biohole, it can be seen the increase in EC in each depth to the time of observation in real time. From the observations of graphs and EC standards, it can be seen that the ability of the soil to provide nutrients in the root growth zone to support the schedule and distribution patterns of planting both during vegetative growth and generative growth periods. So that we will know the proper biohole distance and spacing in order to be able to provide vegetative and generative mass nutrition based on nutrient values monitored through sensors that change the analogue parameters in the micro possessor into digital information transmitted by Wi-Fi in real time. Inseptisol soils fertility simulation based on the number of microbial populations=108/cfu with variable 1: The effective depth for providing root nutrition to a depth of 30 cm with a soil fertility value or Electrolyte Conductivity/ EC 1000 uS/cm to 1900 uS/cm is reached on the 10 to 60th day. Variable 2: The effective depth for providing root nutrition is up to a depth of 24 cm with a soil fertility value or Electrolyte Conductivity/EC 1000 uS/cm to 2350 uS/cm achieved on the 10th to 60th day.

The Design of A Novel Sparse Array Using Two Uniform Linear Arrays considering Mutual Coupling

The sparse arrays using two uniform linear arrays have attracted considerable interest due to the capability of giving analytical expression of sensor location and owning robust direction‐of‐arrival (DOA) facing strong mutual coupling and sensor failure. In order to achieve the maximum consecutive virtual uniform linear array in difference coarray, in this paper, a design method of a novel sparse array using two uniform linear arrays (NSA‐U2) is proposed. We first analyze the relationship between the values of displacement of two subarrays and difference coarray, and then we give the analytical expressions of the displacement and the number of consecutive lags. By discussing the selection of number of subarray sensors, the design of NSA‐U2 is completed. Moreover, through choosing a proper compressed interelement spacing, NSA‐U2 can be robust to mutual coupling effect. Numerical experiments prove the effectiveness and favorable performance of DOA estimation with mutual coupling.

Biohole Effectiveness Analysis Through the Distribution Pattern of Microbes in Real Time for Agricultural Activities once Conservation on Grumosol Soil

This research was conducted on grumosol soils, especially for plantations, with the aim of not only restoring the health and fertility of the soil due to the use of chemical fertilizers and pesticides as well as seeing the pattern of EC distribution at each depth from the center of the biohole based on the time of observation. Through controlled microbial activity, its spread through two types of biohole, namely horizontal and vertical biohole. This research observes in real time through soil parameter sensors connected to the micro controller to changes in soil acidity, infiltration rate, conductivity electrolyte level and porosity level through soil infiltration rate. Through simulations with 2 types of biohole, it can be seen the increase in EC in each depth to the time of observation in real time. From the observations of graphs and EC standards, it can be seen that the ability of the soil to provide nutrients in the root growth zone to support the schedule and distribution patterns of planting both during vegetative growth and generative growth periods. So that we will know the proper biohole distance and spacing in order to be able to provide vegetative and generative mass nutrition based on nutrient values monitored through sensors that change the analog parameters in the micro posesor into digital information transmitted by Wi-Fi in real time. Grumosol soil fertility simulation based on the number of microbial populations=108/cfu with Variable 1: The effective depth for providing root nutrition is up to a depth of 30 cm with a soil fertility value or Electrolyte Conductivity/EC 1000 uS/cm to 1500 uS/cm achieved on the 20th to day 60th day. Varibale 2: The effective depth for providing root nutrition is up to a depth of 24 cm with a soil fertility value or Electrolyte Conductivity/EC 1000 uS/cm to 1500 uS/ cm achieved on the 50th to day 60th day.

Re-framing AI

AI is “essentially detached” from the world. The intrinsic nature of this technology precludes a proper space of negotiation between the different human and non-human actors involved and leads to an ideology of control. The challenge of the designer consists in looking across the black box, as opposed to looking inside, in order to visualise, sense, and experience why AI is leading us, and where, and how. These questions are as important as the algorithmic questions. The missing integration between human and artificial intelligence must be compensated for by mechanisms of social governance. These mechanisms should adopt an approach of constructive engagement with the limits of AI through the inclusion of social learning processes involving the different stakeholders, starting with ordinary citizens. Designing a “good” AI means to give up on a de-situated and socially detached understanding for engaging a community of actors while sharing a common concern.