Weather derivatives: Definitions Heating degree days (HDD): For each day this is max(o, 65-4)where a is the average of the highest and lowest temperature in°F Cooling Degree Days(CDD): For each day this is max( o, A-65)
平推流反应器 Piston Flow Reactor (PFR) 活塞流模型或理想置换模型 This type of units is illustrated in the following figure. This reactor consists of a tube inside which the reaction medium flows. This makes i t t h e s i m p l e s t s t r u c t u r e conceivable f or a continuou s o p e r a ti o n s ys t em . Th e h ea t exchange necessary to add heat to the system or to remove it generally occurs ac ros s the tube wall
The Two-Factor Hul-white Model (equation 24.1, page 571) dx=0(0)+u-ax dt +o,dz1 du= -but +o,dz, where=f(r and the correlation between dz, and dz, is p The short rate reverts to a level dependent on u, and u itself is mean reverting