‎an  oriented perfect path double cover (oppdc) of a‎ ‎graph $g$ is a collection of directed paths in the symmetric‎ ‎orientation $g_s$ of‎ ‎$g$ such that‎ ‎each arc‎ ‎of $g_s$ lies in exactly one of the paths and each‎ ‎vertex of $g$ appears just once as a beginning and just once as an‎ ‎end of a path‎. ‎maxov{'a} and ne{v{s}}et{v{r}}il (discrete‎ ‎math‎. ‎276 (2004) 287-294) conjectured that ...

In this paper an uncapacitated multiple allocation p-hub median problem is discussed. The model minimizes the transportation cost based on inventory service level at hubs through double paths between hubs. Inventory service level is defined as the percent of inventory shortage of vehicles at hubs according to passengers demand and replenishment time of vehicles. A real data from 25 nodes of mun...

The problem of detection and discrimination of double talk and change in the echo path in a telephone channel is consid ered A change in echo path requires fast adaptation of the channel model to be able to equalize the echo dynamics On the other hand the adaption rate should be reduced when double talk occurs Thus it is critical to quickly detect a change in echo path while not confusing it wi...

Railway scheduling is a complex task of rail operators that involves the generation of a conflict-free train timetable. This paper presents a discrete-event simulation-based optimization approach for solving the train timetabling problem to minimize total weighted unplanned stop time in a hybrid single and double track railway networks. The designed simulation model is used as a platform for ge...

Excruciating pain is a common complication following breast surgery which can be effectively treated with double path PECS I and II blocks. Sixty patients undergoing were randomly assigned into two groups: Single-path (SP) group received single-path pectoral nerve (PECS) block, by injecting 0.25% bupivacaine 15 ml the space between serratus muscle pectoralis minor muscle, then withdrawing needl...

We consider edge-decompositions of regular graphs into isomorphic paths. An m-PPD (perfect path decomposition) is a decomposition of a graph into paths of length m such that every vertex is an end of exactly two paths. An m-PPDC (perfect path double cover) is a covering of the edges by paths of length m such that every edge is covered exactly two times and every vertex is an end of exactly two ...

‎An  oriented perfect path double cover (OPPDC) of a‎ ‎graph $G$ is a collection of directed paths in the symmetric‎ ‎orientation $G_s$ of‎ ‎$G$ such that‎ ‎each arc‎ ‎of $G_s$ lies in exactly one of the paths and each‎ ‎vertex of $G$ appears just once as a beginning and just once as an‎ ‎end of a path‎. ‎Maxov{'a} and Ne{v{s}}et{v{r}}il (Discrete‎ ‎Math‎. ‎276 (2004) 287-294) conjectured that ...

A key issue in software testing is the actual generation of test data from program input domain. Obviously, more accurate input domain is, more efficient test generation is. This paper presents a path-oriented automatic random testing method based on double constraint propagation. For a given path, its domain can be reduced by splitting an input variable domain and executing a double constraint...