For contents delivery systems such as video-ondemand service, an optimum design is presented to maximize the utility of the system with priority classes. The willingness-to-pay (WTP) is introduced for a measure of utility, and the optimum design is discussed to maximize the utility (revenue). For the system with two priority classes, the optimum condition is given in terms of the traffic load, ...

the taguchi design of experiments was used to test the relative importance of medium components and environmental factors on poly(β-hydroxybutyrate)(phb) production by ralstonia eutropha. the optimum condition was obtained as: fructose concentration, 15 g/l; c/n ratio, 7.4; agitation speed 200 rpm; culture time, 40 h; temperature, 25 ° c; seed age, 15 h. at optimum condition the yield of phb pr...