A design variable optimization system including a performance value calculating section for performing an analysis on a design article using numerous design variables and for calculating a performance value for evaluating the performance of the design article using each of the design variables, based on the result of analysis. In addition, the invention features compositions useful for the treatment or prevention of a parasitic mite infestation in a honey bee hive. The stimulation electrode is useful, for example, in cardiac pacemakers, neuro-stimulation devices and other human implants. Personalization data contained in the VSC may be tested in an application environment before a personalized real smart card is available. The shielding gas permits low sulfur, high chromium, austenitic stainless steel pipes to be joined with welds having sufficient penetration, strength, corrosion resistance and durability for practical use. The ball drive assembly for one of the supports has a ball wheel housing containing a spherical, rigid ball, a drive shaft extending into the ball, a first driver for initiating rotating movement of the ball with respect to the ball wheel housing, and a second driver for initiating swiveling left and right movement of the ball so that it twists laterally of the ball wheel housing.