An airline has p flight legs that it wishes to service by the fewest possible planes. to do so, it must determine the most efficient way to combine these legs into flight schedules. the start time for flight i is ai and the finishing time is bi . the plane requires rij hours to return from the point of destination of flight i to the point of origin of flight j. formulate this as a network flow problem. you should clearly state how to construct the network from the given data, and justify that your formulation correctly models the problem

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia