The LVRT (Low Voltage Ride Through) is the main characteristic of every power system in faulty conditions. When fault occurs, it is essential for power system such as microgrid to control the voltage and frequency normally. Naturally in fault status, the unbalanced voltage and current are inevitable, but with the aid of LVRT technique, microgrid can keep stability in main system parameters such...

Many enumeration problems, such as that of counting nonnegative integer matrices with given row and column sums, have solutions which can be expressed as coefficients of symmetric functions. We show here how useful formulas can be obtained from these symmetric function generating functions. In some cases, the symmetric functions yield reasonably simple explicit formulas or generating functions ...

T his paper proposes a new unit root test against the alternative of symmetric or asymmetric exponential smooth transition autoregressive (AESTAR) nonlinearity that accounts for multiple smooth breaks. We provide small sample properties which indicate the test statistics have good empirical size and power. Also, we compared small sample properties of the test statistics with Christop...

This study introduces the free vibration analysis of multilayered symmetric sandwich Timoshenko beams, made of functionally graded materials with two edge cracked, using the finite element method and linear elastic fracture mechanic theory. The FG beam consists of 50 layers, located symmetrically to the neutral plane, whose material properties distribution change along the beam thickness, accor...

The conceptions of χ-value and K-rotation symmetric Boolean functions are introduced by Cusick. K-rotation symmetric Boolean functions are a special rotation symmetric functions, which are invariant under the k − th power of ρ. In this paper, we discuss cubic 2-value 2-rotation symmetric Boolean function with 2n variables, which denoted by F2n(x2n). We give the recursive formula of weight of F2...

A t-(v, k, λ) design is quasi-symmetric if there are only two block intersection sizes. We adapt the Kramer-Mesner construction method for designs with prescribed automorphism groups to the quasi-symmetric case. Using the adapted method, we find many new quasi-symmetric 2-(28, 12, 11) and 2-(36, 16, 12) designs, establish the existence of quasi-symmetric 2-(56, 16, 18) designs, and find three n...

A new class of non-totally symmetric functions which can be represented as simple regular symmetric arrays without redundancy is identified. Regular circuits are becoming crucialy important for deep submicron technologies, which needs new layout approaches to fully utilized their potential. The new class of functions contains the classes of totally symmetric and totally symmetric with mixed pol...

In the present paper the Hyers-Ulam stability of monomial functional equations for functions defined on a power-associative, power-symmetric groupoid is proved.