‎For a set of non-negative integers~$L$‎, ‎the $L$-intersection number of a graph is the smallest number~$l$ for which there is an assignment of subsets $A_v subseteq {1,dots‎, ‎l}$ to vertices $v$‎, ‎such that every two vertices $u,v$ are adjacent if and only if $|A_u cap A_v|in L$‎. ‎The bipartite $L$-intersection number is defined similarly when the conditions are considered only for the ver...

By pure analogy with a usual three-dimensional origami, we can fold a regular octahedral material along flat faces in 4-space. The octahedron comprises four congruent tetrahedra. We will show a procedure to fold a tetrahedron along bisectors of the dihedral angles. This procedure demonstrates that each two of four surfaces of the given tetrahedron coincide with each other and that the point of ...

Nontrivial periodic solutions of Lagrange Equations are investigated. Sublinear and superlinear nonlinearity are included. Convexity assumptions are significiently relaxed. The method used is the duality developed by the authors.

Traffic lights have been existing for around 100 years. The first signals were installed for safety reasons for avoiding accident between opposed traffic flows at an intersection. Due to a continually increasing traffic, the traffic lights became a powerful tool for controlling the flows : the stake was to increase the intersection capacity and to decrease the congestion and the overall delay. ...

environment throughout the evacuation network. Although both have proven reasonably effective as capacity-increasing measures (for accelerating the evacuation process), their combination can enhance performance further. Solving this design problem with lane reversal and crossing elimination, however, poses a great challenge, because of the complex mutual connectivity requirement imposed by the ...