We study spectrum inclusion regions for complex Jacobi matrices that are compact perturbations of the discrete laplacian. The condition sufficient for the lack of discrete spectrum for such matrices is given.

1-type and biharmonic curves by using laplace operator in lorentzian 3-space arestudied and some theorems and characterizations are given for these curves.

Linear mixed models (LMM) and generalized linear mixed models (GLMM) are widely used in regression analyses. With the variance structure dependent on the random effects with their variance components, the parameter estimation of LMMs is more complicated than linear models (LM). Generally, we use maximum likelihood estimation (MLE) together with some procedure such as derivative free optimizatio...