<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">John R. Graef</style></author><author><style face="normal" font="default" size="100%">LINGJU KONG</style></author><author><style face="normal" font="default" size="100%">MIN WANG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">TWO NONTRIVIAL SOLUTIONS FOR A DISCRETE FOURTH ORDER PERIODIC BOUNDARY VALUE PROBLEM</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">34B08</style></keyword><keyword><style  face="normal" font="default" size="100%">34B15</style></keyword><keyword><style  face="normal" font="default" size="100%">39A10</style></keyword><keyword><style  face="normal" font="default" size="100%">58E3</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2015</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.acadsol.eu/en/articles/19/4/1.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">19</style></volume><pages><style face="normal" font="default" size="100%">10</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We study the discrete fourth order periodic boundary value problem with a parameter $${ \left\{ \begin{array}{1}∆^4u(t − 2) − ∆ \left(p(t − 1)∆_u(t − 1)\right)&amp;nbsp;+ q(t)u(t) = λf(t, u(t)), \ t ∈ [1, N]_Z,\\&amp;nbsp;∆^iu(−1) = ∆^iu(N − 1), \ \&amp;nbsp; &amp;nbsp;i = 0, 1, 2, 3.\end{array}\right. }$$ By using variational methods and the mountain pass lemma, sufficient conditions are found under which the above problem has at least two nontrivial solutions. One example is included to illustrate the result.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><section><style face="normal" font="default" size="100%">487</style></section></record></records></xml>