A Full-Period Mathematical Model for a Hybrid-Rotor Bearingless Switched Reluctance Motor

A bearingless switched reluctance motor (BSRM) has the combined characteristics of a switched reluctance motor (SRM) and a magnetic bearing. The hybrid-rotor BSRM (HBSRM) discussed in the paper has a twelve-pole stator and an eight-pole hybrid rotor, which is composed of a cylindrical rotor and a salient-pole rotor. Although the asymmetry of the hybrid rotor makes the structure and magnetic field of the HBSRM more complex, it can always produce a significant amount of magnetic pulling force to levitate a rotor shaft at all the rotor angular positions of each phase, which is not available in a traditional BSRM. The classical mathematical model for a conventional BSRM is valid only when its rotor rotates from the start of the overlap position to the aligned position, and the radial force and torque derived from this model are discontinuous at the aligned positon, which is harmful to the motor’s stable operation. In this paper, a full-period mathematical model on the assumption that the gap permeance is cut apart by straight lines or improved elliptical lines for a 12/8-pole HBSRM is provided. On the basis of this mathematical model, the continuity of the radial force and torque at all the rotor angular positions can be guaranteed, and the fine characteristics of this mathematical model have been verified by simulations.

Asymptotically accurate error estimates of exponential convergence for the trapezoidal rule

In many applied problems, efficient calculation of quadratures with high accuracy is required. The examples are: calculation of special functions of mathematical physics, calculation of Fourier coefficients of a given function, Fourier and Laplace transformations, numerical solution of integral equations, solution of boundary value problems for partial differential equations in integral form, etc. For grid calculation of quadratures, the trapezoidal, the mean and the Simpson methods are usually used. Commonly, the error of these methods depends quadratically on the grid step, and a large number of steps are required to obtain good accuracy. However, there are some cases when the error of the trapezoidal method depends on the step value not quadratically, but exponentially. Such cases are integral of a periodic function over the full period and the integral over the entire real axis of a function that decreases rapidly enough at infinity. If the integrand has poles of the first order on the complex plane, then the Trefethen-Weidemann majorant accuracy estimates are valid for such quadratures. In the present paper, new error estimates of exponentially converging quadratures from periodic functions over the full period are constructed. The integrand function can have an arbitrary number of poles of an integer order on the complex plane. If the grid is sufficiently detailed, i.e., it resolves the profile of the integrand function, then the proposed estimates are not majorant, but asymptotically sharp. Extrapolating, i.e., excluding this error from the numerical quadrature, it is possible to calculate the integrals of these classes with the accuracy of rounding errors already on extremely coarse grids containing only 10 steps.

Climate Influence in Dendrochronological Series of Araucaria angustifolia from Campos do Jordão, Brazil

A dendrochronological series of Araucaria angustifolia was analyzed for a better understanding of the climatic factors that operate in Campos do Jordão city, São Paulo state, Brazil. The dendroclimatic analysis was carried out using 45 samples from 16 Araucaria angustifolia trees to reconstruct the precipitation and the temperature over the 1803–2012 yearly interval. To this end, Pearson’s correlation was calculated between mean chronology and the climatic time series using a monthly temporal resolution to calibrate our models. We obtained correlations as high as r=0.22(α=0.1) for precipitation (February), and r=0.21(α=0.1) for temperature (March), both corresponding to the end of the summer season. Our results show evidence of temporal instabilities because the correlations for the halves of 1963–2012 were very different, as well as for the full period. To overcome this problem, the dendrochronological series and the climatic data were investigated using the wavelet techniques searching for time-dependent cause–effect relationships. From these analyses, we find a strong influence of the region’s precipitation and temperature on the growth of tree ring widths.

Co-simulation of linear congruential generator by using Xilinx system generator and MATLAB Simulink

<p>Arbitrary numerals are utilized in a wide range of uses. Genuine arbitrary numeral generators are moderate and costly for some applications while pseudo arbitrary numeral generators (RNG) do the trick for most applications. This paper fundamentally concentrates around the co-simulation of the linear congruential generator (LCG) model utilizing the Xilinx System generator and checking on Matlab Simulink. The design is obtained from the LCG calculation offered by Lehmer. Word lengths decrease strategy has been utilized to streamline the circuit. Simulation has been done effectively. The effective N bit LCG is structured and tried by utilizing demonstrating in MatLab Simulink. The Co-simulation of the model is done by utilizing the Xilinx system generator. This paper conducts an exhaustive search for the best arbitrary numeral generator in a full period linear congruential generator (LCG) with the largest prime numbers.</p>

Evaluation of the effect of the capitation compensation mechanism among pulmonary tuberculosis patients with a full period of treatment

Background PTB is an infectious disease, which not only seriously affects people’s health, but also causes a heavier disease economic burden on patients. At present, reform of the medical insurance payment can be an effective method to control medical expenses. Therefore, our study is to explore the compensation mechanism for pulmonary tuberculosis (PTB) patients with a full period of treatment, to alleviate the financial burden of PTB patients and provide a reference and basis for the reform of PTB payment methods in other regions and countries. Methods The quantitative data of PTB patients was collected from the first half of 2015 to the first half of 2018 in Dehui Tuberculosis Hospital in Jilin Province, and medical records of PTB patients registered in the first half of 2018 (n = 100) from the hospital was randomly selected. Descriptive analysis of these quantitative data summarized the number, cost, medication and compliance. Semi-structured in depth interviews with policymakers and physicians were conducted to understand the impact of interventions and its causes. Results After implementation of the compensation mechanism, the number of PTB patient visits in 2018 was increased by 14.2%, average medical costs for outpatients and inpatients were significantly reduced by 31.8% and 47.0%, respectively, and the auxiliary medication costs was reduced by 36.5%. Moreover, the hospital carried out standardized management of tuberculosis, and the patient compliance was very high, reaching almost 90%. Conclusions The capitation compensation mechanism with a full period of treatment was a suitable payment method for PTB, and it is worthy of promotion and experimentation. In addition, the model improved patient compliance and reduced the possibility of drug-resistant PTB. However, due to the short implementation time of the model in the pilot areas, the effect remains to be further observed and demonstrated.

Homogeneous and heterogeneous propagation of COVID-19 from super-spreading to super-isolation

We investigated daily COVID-19 cases and death in the 337 lower tier local authority regions in England and Wales to better understand how the disease propagated over a 10-month period. Population density scaling models revealed residual variance and skewness to be sensitive indicators of the dynamics of propagation. Lockdowns and schools reopening triggered increased variance indicative of outbreaks with local impact and country scale heterogeneity. University reopening and December holidays triggered reduced variance indicative of country scale homogenisation which reached a minimum after New Year. Homogeneous propagation was associated with better correspondence with normally distributed residuals while heterogeneous propagation was more consistent with skewed models. Skewness varied from strongly negative to strongly positive revealing an unappreciated feature of community propagation. Hot spots and super-spreading events are well understood descriptors of regional disease dynamics that would be expected to be associated with positively skewed distributions. Positively skewed behaviour was observed; however, negative skewness indicative of “cold-spots” and “super-isolation” dominated for approximately 4 months during the period of study. In contrast, death metrics showed near constant behaviour in scaling, variance, and skewness metrics over the full period with rural regions preferentially affected, an observation consistent with regional age demographics in England and Wales.

A Hybrid Inversive Congruential Pseudorandom Number Generator with High Period

Though generating a sequence of pseudorandom numbers by linear methods (Lehmer generator) displays acceptable behavior under some conditions of the parameters, it also has undesirable features, which makes the sequence unusable for various stochastic simulations. An extension which showed promise for such applications is a generator obtained by using a first-order recurrence based upon the inversive modulo a prime or a prime power, called inversive congruential generator (ICG). A lot of work has been dedicated to investigate the periods (under some conditions of the parameters), the lattice test passing, discrepancy and other statistical properties of such a generator. Here, we propose a new method, which we call hybrid inversive congruential generator (HICG), based upon a second order recurrence using the inversive modulo $M$, a power of 2. We investigate the period of this pseudorandom numbers generator (PRNG) and give necessary and sufficient conditions for our PRNG to have periods $M$ (thereby doubling the period of the classical ICG) and $M/2$ (matching the one of the ICG). Moreover, we show that the lattice test complexity for a binary sequence associated to (a full period) HICG is precisely M/2.

Evaluation of the Effect of the Capitation Compensation Mechanism among Tuberculosis Patients with a Full Period of Treatment

Background: To explore the compensation mechanism for pulmonary tuberculosis patients with a full period of treatment, to alleviate the financial burden of pulmonary tuberculosis patients and to provide a reference and basis for the reform of tuberculosis payment methods in other regions and countries.Methods The funding operations of medical insurance institutions and the actual operating expenses of pilot hospitals from the Dehui Tuberculosis Hospital in Jilin Province were collected from the first half of 2015 to the first half of 2018, and the operational effects were analysed through quantitative and qualitative methods.Results After implementing the compensation mechanism, the medical expenses of tuberculosis patients decreased significantly, and the economic burden of the disease was reduced; the hospital's medical service capacity was improved, and internal management was significantly improved; and the medical insurance fund did not experience overspending, thus leading to a "triple win-win" situation.Conclusion The capitation compensation mechanism with a full period of treatment is a suitable payment method for TB diagnosis and treatment, and its effect is obvious, achieving a "triple win-win" for medical insurance, hospitals and patients. It is recommended to continue to promote this model to effectively reduce the financial burden of tuberculosis patients. However, in the early stage of the implementation of the plan, due to the relatively low understanding of the reform of hospitals and patients, there will be patient loss and poor compliance. Therefore, the hospital should change the management concept, incorporate the goal of payment method reform into performance management, and require all patients to be included in the treatment path to achieve standardized management of the entire treatment process. This mechanism also provides a reference for the reform of payment methods for tuberculosis in other regions or countries.

Breeding reserves for improving the efficiency of dairy farming

The article presents scientific research of breeding reserves for improving the economic efficiency of dairy cattle breeding. As a result of research at the enterprises of the Omsk region, it was found that with the improvement of the productive qualities of breeding animals, farms can receive an additional 144.84 tons of milk and 151 head of calves, for commodity enterprises the reserves are 572.205 tons of milk and 101 head of calves. In breeding reproducers, as a result of the First stage of return crossing and changes in the structure of the milking herd, the gross milk yield from the entire livestock for the full period of productive use of cows will increase by 221 tons and at the Second stage of crossing – by the same amount. All other things being equal, after two stages, the profit amount may increase by 4428 thousand rubles. A similar situation is predicted in commodity herds. According to the results of the return crossing at the end of First and Second stages, an increase in the gross milk yield from the entire livestock of 35.0 tons is expected. According to the forecast calculations, the change in the age composition of the herd of cows will have a positive impact on the economic efficiency of dairy farming in farms. In general, the return crossing on black-and-white cows up to 75% of the Holstein bloodline will increase the profit from the sale of milk by 108 thousand rubles, which proves the expediency for enterprises to use the studied crossing.