Abstract: Methods and systems for performing preference analysis, and, more particularly, methods and systems for performing preference analysis, are described.

Abstract: A method for preventing the dropping of individual bricks from a sprung arch roof employed in a continuous tank-type glass melting furnace, the dropping of the bricks normally occurring during heat-up of the furnace. The slightly tapered bricks employed in constructing the roof are oriented with their long axis in the vertical direction and, as heating occurs and the structure differentially expands and the bricks dry out, some become sufficiently loose to drop from the roof into the tank of the furnace. In visually observing the interior surface of the roof during heat-up, it can be seen which bricks are settling and likely to drop therefrom. These bricks are pulled up through the roof from above by a suction cup and mortar is placed around the bricks. The bricks are then dropped back into place with the mortar holding the bricks until they become wedged firmly in place as the temperature of the roof increases.