This paper is devoted to the existence of positive periodic solutions for system a class nonlinear delay differential equations with conditions. Our analysis based on Mawhin coincidence degree theorem. An example also presented illustrate effectiveness main result.

the purpose of this study is to investigate the effect of injection parameters on a heavy duty diesel engine performance and emission characteristics. in order to analyze the injection and spray characteristics of diesel fuel with employing high-pressure common-rail injection system, the injection characteristics such as injection delay, injection duration, injection rate, number of nozzle hole...

priority queues have a great importance in the study of computer communication networks in which different types of traffic require different quality of service standards. the discrete-time non-preemptive priority queuing model with priority jumps is proposed in this paper. on the basis of probability generating functions mean system contents and mean queuing delay characteristics are obtained....