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Determination of the factors influencing solar irradiation plays an important role in the performance of a prediction model based on machine learning techniques. This study compared the results obtained using a linear correlation analysis and stepwise regression method to identify the key meteorological, weather, and radiation factors that significantly affect the solar irradiation on the following day, as well as the difference between the quantities of solar irradiation on the current day and following day. These factors were used to establish prediction models for the Qinghai–Tibet Plateau, which has a complex topography and weather caprices. The results indicated that the stepwise regression method was capable of screening more effective influencing factors and the corresponding predictive accuracy was acceptable even under the weather conditions of the plateau. [ABSTRACT FROM AUTHOR]

The effect of solution treatment on the martensitic transformation behavior of a NiCoMnSn polycrystalline alloy fabricated by an arc melting method was investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and differential scanning calorimetry (DSC). The examination indicates the presence of severe chemical segregation in the dendritic as-cast structure because of solidification. This chemical segregation completely impedes the intrinsic martensitic transformation. Annealing at 1223 K for 24 h is identified as the threshold annealing condition to eliminate the microstructural segregation and begin the martensitic transformation, as indicated by a broad and obscure feature. Annealing at 1273 K for 24-48 h is found to be effective at promoting notably the martensitic transformation, but the martensitic transformation exhibits a multiple-step feature. Complete homogeneity is achieved by annealing at 1273 K for 72 h, which produces a sharp, single-step martensitic transformation. The microstructural evolution and the valence electron concentrations of alloys (e/a ratio) are evaluated, which are reflective of the degree of compositional homogeneity of alloys, confirming that high annealing temperature and long holding time are vital to reveal the intrinsic martensitic behavior of this alloy. The adequately homogenized alloy displays a martensitic transformation at 292 K and an enthalpy of 11.2 J/g. [ABSTRACT FROM AUTHOR]

A parametric variational principle and the corresponding numerical algorithm are proposed to solve a linear-quadratic (LQ) optimal control problem with control inequality constraints. Based on the parametric variational principle, this control problem is transformed into a set of Hamiltonian canonical equations coupled with the linear complementarity equations, which are solved by a linear complementarity solver in the discrete-time domain. The costate variable information is also evaluated by the proposed method. The parametric variational algorithm proposed in this paper is suitable for both time-invariant and time-varying systems. Two numerical examples are used to test the validity of the proposed method. The proposed algorithm is used to astrodynamics to solve a practical optimal control problem for rendezvousing spacecrafts with a finite low thrust. The numerical simulations show that the parametric variational algorithm is effective for LQ optimal control problems with control inequality constraints. [ABSTRACT FROM AUTHOR]

Generalized thermo-elastic theory, which is based on the non-Fourier theory, indicates that there is a time delay between the heat flux vector and the temperature gradient. At present, the traditional numerical method for solving the thermo-elastic problem subjected to high-frequency heat source generally fails to properly capture discontinuities of impulsive waves in space and produces spurious numerical oscillations in the simulation of high modes and sharp gradients. In the paper, a time discontinuous Galerkin finite element method (DGFEM) for the solution of generalized thermo-elastic coupled problems is presented on the basis of well-known Lord-Shulman theory. The essential feature of the DGFEM is that the general temperature-displacement vector and its temporal gradient are assumed to be discontinuous and interpolated individually at each time level in time domain, respectively. In order to filter out the spurious wave-front oscillations, an artificial damping scheme is implemented in the final finite element formula. Numerical results show that the present DGFEM shows good abilities and provides much more accurate solutions for generalized thermo-elastic coupled behavior. It can capture the discontinuities effectively at the wave front and filter out the effects of spurious numerical oscillation induced by a high-frequency thermal shock. [ABSTRACT FROM AUTHOR]

By converting an optimal control problem for nonlinear systems to a Hamiltonian system, a symplecitc-preserving method is proposed. The state and costate variables are approximated by the Lagrange polynomial. The state variables at two ends of the time interval are taken as independent variables. Based on the dual variable principle, nonlinear optimal control problems are replaced with nonlinear equations. Furthermore, in the implementation of the symplectic algorithm, based on the 2 algorithm, a multilevel method is proposed. When the time grid is refined from low level to high level, the initial state and costate variables of the nonlinear equations can be obtained from the Lagrange interpolation at the low level grid to improve efficiency. Numerical simulations show the precision and the efficiency of the proposed algorithm in this paper. [ABSTRACT FROM AUTHOR]

Interferon- β has anti-viral, anti-proliferation and multifunctional immunomodulatory activities and shows promising clinical effects for treatment of inflammatory disorders. The recombinant human interferon- β (huIFN- β) 1b was expressed in the food-grade lactic acid bacterium, Lactococcus lactis, using a nisin-controlled gene expression system. huIFN- β production from recombinant strains (with and without LEISSTCDA propeptide) was approximately 21 and 7 μg l−1, respectively. Moreover, 95% (former strain) and 88% (latter strain) of total recombinant proteins were secreted into the culture medium. The biological activities of huIFN- β from recombinant strains revealed similar antiviral activities of 107 I.U. mg−1. These results demonstrate the potential application of recombinant strains as a food grade vehicle to deliver bioactive huIFN- β in vivo. [ABSTRACT FROM AUTHOR]

This paper gives the sensitivity analysis for some scheduling problems, including the following: what are the limits to a parameter change such that the solution remain optimal? Given a specific change of a parameter, what is the new optimal cost? Given a specific change of a parameter, what is a new optimal solution? Here, the concern is mainly with the sensitivity analysis for some single-machine and flowshop scheduling problems with polynomial time algorithms. It is shown that, for these problems, the sensitivity analysis results depend on the positions of jobs with changed parameters. [ABSTRACT FROM AUTHOR]

The general principles and realizations of FBG wavelength tuning with elastic beams are proposed and demonstrated. Theories and experiments show that when displacement at the center point of simple beams, deflection of cantilever beams and torsion strain of torsion beams are relatively small, Bragg wavelength shifts of sensing FBGs have linear relationship with applied external stress, lateral displacement, torque and torsional angles, respectively. The experimental results indicate that the curvature sensitivity of the simple beam is 1.65 nm/m−1, the displacement sensitivity of the equivalent-strain cantilever beam is 4.4 cm/kg and the torque and torsional angle sensitivities of the torsion beam are 6.27 nm/Nm and 0.0867 nm/degree, respectively. [ABSTRACT FROM AUTHOR]