A gray-scale representation method for a plasma display panel, which method includes arranging, in time sequence, a plurality of subfields each having a brightness weight and achieving gray-scale representation by a combination of the subfields, each subfield including an address period and a sustain period. This method may be used to determine the diffusion of the fluid or the restricted diffusion of the fluid through the porous media if the fluid is within a porous media. The shell, light section, and light source board have apertures for providing an air cooling channel through the light. Adequate SPLs are provided when the ear is not sealed to the device by the combined use of distal and central ports. By applying compressive force to the bone by the tabs, the fragments are subjected to compression force across the fracture and to a torque which opposes bone shortening. A step is provided for constructing a prototype filter of a size greater than the initial size to implement the modulated transform of the greater size by inserting at least one coefficient between two consecutive coefficients of the initial prototype filter.