this paper deals with the boundary value problem involving the differential equationbegin{equation*}    ell y:=-y''+qy=lambda y, end{equation*} subject to the standard boundary conditions along with the following discontinuity  conditions at a point $ain (0,pi)$ begin{equation*}    y(a+0)=a_1 y(a-0),quad y'(a+0)=a_1^{-1}y'(a-0)+a_2 y(a-0),end{equation*}where $q(x),  a_1 , a_2$ are  real, $qin l...

we consider the coupled system$f(x,y)=g(x,y)=0$,where$$f(x, y)=bs 0 {m_1}   a_k(y)x^{m_1-k}mbox{ and } g(x, y)=bs 0 {m_2} b_k(y)x^{m_2-k}$$with entire functions $a_k(y), b_k(y)$.we    derive a priory estimates  for the sums of the rootsof the considered system andfor the counting function of  roots.

2,109,698 A 3/1938 Harman ......................... 18/53 2,186,769 A 1/1940 Schirm ......... ... 260/377 4,123,530 A 10/1978 Corvi-Mora ......... ... 424/250 5,506.258 A 4/1996 Christophe et al. ......... 514/423 5,552,411 A 9/1996 Downing et al. ........... 514/312 5,554,621 A 9/1996 Poindexter et al. ......... 514/278 5,571,921 A 11/1996 Bender et al. .............. 546/199 5,602,024 A 2/199...

Literary genres — alive and kicking : The productivity of a literary concept In: Revue belge de philologie et d'histoire. Tome 75 fasc. 3, 1997. Langues et littératures modernes-Moderne taal-en letterkunde. pp. 653-663. Fishelov David. Literary genres — alive and kicking : The productivity of a literary concept. In: Revue belge de philologie et d'histoire. Tome 75 fasc. 3, 1997. Langues et litt...

In this paper, we consider orthogonal stability of mixed type additive and cubic functional equation of the form $$f(2x+y)+f(2x-y)-f(4x)=2f (x+y)+2f(x-y)-8f(2x) +10f(x)-2f(-x),$$ with $xbot y$, where $bot$  is orthogonality in the sense of Ratz.

recently the previous caspian ecosystem is in a catastrophic condition which caused changes in the absolute and relative abundance of the commercially important caspian kutum (rutilus frisii kutum) in iranian waters. the paper presents estimates of yield-per-recruit and spawning biomass-per-recruit under various harvest strategies of fmax, f0.1, f30%. it proposes a method for estimating accepta...

In this paper, we use the structure theory to prove an analog to a well-known theorem of Herstein as follows: Let R be a ring with center C such that for all x,y ? R either [x,y]= 0 or x-x [x,y]? C for some non negative integer n= n(x,y) dependingon x and y. Then R is commutative.

Consider y" (t) + A (t)y (t) + 0, y is a real n-dimensinal vector and A(t) is a real nxn matrix, continuous on some interval. Some positivity properties of solutions and conjugate points of y"(t) + A(t)y (t) = 0 appeared in literature. We prove similar results for focal points