Analyzing financial factors to improve production and business efficiency

In order to complete this paper, the authors would like to thank Thai Nguyen Iron and Steel Joint Stock Company for their support in discussing and providing necessary information related to the article, thank SHB Commercial Joint Stock Bank for supporting the review of the paper and financial results for the authors in the research process. The authors also thank the Faculty of Economic Information Systems, Thai Nguyen University of Information and Communication Technology.Purpose: The paper’s aim is to analyze the business and production activities of an enterprise on researching and analyzing financial situation and factors affecting financial indices. On this basis, the article gives a panoramic view of the current financial situation and offers effective solutions to manage finances. Design/Methodology/Approach: In this article we have conducted a survey and analyzed the reality of the financial situation of TISCO in the period of 2016-2018. On that basis, the authors proposed an effective financial management solution for TISCO. Findings: On the basis of analyzing the advantages of an enterprise financial factor analysis methods the paper took advantage of the strengths of the existing method combined with testing analysis, descriptive statistics and charts to assess the current situation and give general and specific overview of the financial situation of large Vietnamese enterprises such as TISCO. The paper suggests a solution for the corporate restructuring of TISCO. Practical implications: Based on the methods of financial factor analysis combined with descriptive statistical analysis the article has been applied to analyze and assess the actual financial situation in large enterprises in Vietnam and make recommendations on corporate financial management to help businesses operate more effectively. Originality/Value: The authors have conducted research and applied the analysis of the financial reality of a large enterprise that is now in a period of great loss. This article gives an accurate, honest and objective assessment of the reality of TISCO making effective recommendations on corporate financial management.peer-reviewe

Super-Eddington winds from Type I X-ray bursts

We present hydrodynamic simulations of spherically symmetric super-Eddington winds from radius-expansion type I X-ray bursts. Previous studies assumed a steady-state wind and treated the mass-loss rate as a free parameter. Using MESA, we follow the multi-zone time-dependent burning, the convective and radiative heating of the atmosphere during the burst rise, and the launch and evolution of the optically thick radiation-driven wind as the photosphere expands outward to radii $r_{\rm ph} \gtrsim 100\text{ km}$. We focus on neutron stars (NSs) accreting pure helium and study bursts over a range of ignition depths. We find that the wind ejects $\approx 0.2\%$ of the accreted layer, nearly independent of ignition depth. This implies that $\approx 30\%$ of the nuclear energy release is used to unbind matter from the NS surface. We show that ashes of nuclear burning are ejected in the wind and dominate the wind composition for bursts that ignite at column depths $\gtrsim 10^9\text{ g cm}^{-2}$. The ejecta are composed primarily of elements with mass numbers $A> 40$, which we find should imprint photoionization edges on the burst spectra. Evidence of heavy-element edges has been reported in the spectra of strong, radius-expansion bursts. We find that after $\approx 1\text{ s}$ the wind composition transitions from mostly light elements ($^4$He and $^{12}$C), which sit at the top of the atmosphere, to mostly heavy elements ($A>40$), which sit deeper down. This may explain why the photospheric radii of all superexpansion bursts show a transition after $\approx 1\text{ s}$ from a superexpansion ($r_{\rm ph}>10^3\text{ km}$) to a moderate expansion ($r_{\rm ph}\sim 50\text{ km}$).Comment: 13 pages, 13 figures. Matches the version published in Ap

Nonlinear dynamical tides in white dwarf binaries

Compact white dwarf (WD) binaries are important sources for space-based gravitational-wave (GW) observatories, and an increasing number of them are being identified by surveys like ZTF. We study the effects of nonlinear dynamical tides in such binaries. We focus on the global three-mode parametric instability and show that it has a much lower threshold energy than the local wave-breaking condition studied previously. By integrating networks of coupled modes, we calculate the tidal dissipation rate as a function of orbital period. We construct phenomenological models that match these numerical results and use them to evaluate the spin and luminosity evolution of a WD binary. While in linear theory the WD's spin frequency can lock to the orbital frequency, we find that such a lock cannot be maintained when nonlinear effects are taken into account. Instead, as the orbit decays, the spin and orbit go in and out of synchronization. Each time they go out of synchronization, there is a brief but significant dip in the tidal heating rate. While most WDs in compact binaries should have luminosities that are similar to previous traveling-wave estimates, a few percent should be about ten times dimmer because they reside in heating rate dips. This offers a potential explanation for the low luminosity of the CO WD in J0651. Lastly, we consider the impact of tides on the GW signal and show that LISA and TianGO can constrain the WD's moment of inertia to better than 1% for deci-Hz systems.Comment: 21 pages, 18 figures. Submitted to MNRA

Surplus Angle and Sign-flipped Coulomb Force in Projectable Horava-Lifshitz Gravity

We obtain the static spherically symmetric vacuum solutions of Horava-Lifshitz gravity theory, imposing the detailed balance condition only in the UV limit. We find the solutions in two different coordinate systems, the Painlev\'e-Gullstrand coordinates and the Poincare coordinates, to examine the consequences of imposing the projectability condition. The solutions in two coordinate systems are distinct due to the non-relativistic nature of the HL gravity. In the Painleve-Gullstrand coordinates complying with the projectability condition, the solution involves an additional integration constant which yields surplus angle and implies attractive Coulomb force between same charges.Comment: 13 page

A lagrangian approach to weakly coupled Hamilton-Jacobi systems

We study a class of weakly coupled Hamilton–Jacobi systems with a specific aim to perform a qualitative analysis in the spirit of weak KAM theory. Our main achievement is the definition of a family of related action functionals containing the Lagrangians obtained by duality from the Hamiltonians of the system. We use them to characterize, by means of a suitable estimate, all the subsolutions of the system, and to explicitly represent some subsolutions enjoying an additional maximality property. A crucial step for our analysis is to put the problem in a suitable random frame. Only some basic knowledge of measure theory is required, and the presentation is accessible to readers without background in probability

Holographic Non-Fermi Liquid in a Background Magnetic Field

We study the effects of a non-zero magnetic field on a class of 2+1 dim non-Fermi liquids, recently found in 0903.2477 by considering properties of a fermionic probe in an extremal AdS^4 black hole background. Introducing a similar fermionic probe in a dyonic AdS^4 black hole geometry, we find that the effect of a magnetic field could be incorporated in a rescaling of the probe fermion's charge. From this simple fact, we observe interesting effects like gradual disappearance of the Fermi surface and quasi particle peaks at large magnetic fields and changes in other properties of the system. We also find Landau level like structures and oscillatory phenomena similar to the de Haas-van Alphen effect.Comment: 20 pages, latex, 6 figure