Part I Yingkang: Remembering Professor Yingkang Hu.- Remembrances.- On Some Properties of Moduli of Smoothness with JacobiWeights.- Part II Approximation Theory, Harmonic and Complex Analysis, Splines and Classical Fourier Theory.- Special Difference Operators and the Constants in the Classical Jackson-Type Theorems.- Comparison Theorems for Completely and Multiply Monotone Functions and Their Applications.- Concerning Exponential Bases on Multi-Rectangles of Rd.- Hankel Transforms of General Monotone Functions.- Univalence of a Certain Quartic Function.- Finding, Stabilizing, and Verifying Cycles of Nonlinear Dynamical Systems.- Finding Orbits of Functions Using Suffridge Polynomials.- The Sharp Remez-Type Inequality for Even Trigonometric Polynomials on the Period.- The Lebesgue Constants of Fourier Partial Sums.- Liouville-Weyl Derivatives of Double Trigonometric Series.- Inequalities in Approximation Theory Involving Fractional Smoothness in Lp, 0