A method for security planning with hard security constraints includes: receiving security-related requirements of a network to be developed using system inputs and processing components; and generating the network according to the security-related requirements, wherein the network satisfies hard security constraints. Detection circuitry in each interface circuit detects slot position. A first heat exchanger cools cooling air supplied to the gas turbine engine. When a voltage is applied between the first and second electrode structural bodies, since the direction of the electric field substantially coincides with the c axis of the bismuth layer structured compound, the bismuth layer structured compound can be prevented from exhibiting the ferroelectric property and made to sufficiently exhibit the paraelectric property. This advantageously allows the microcontroller to adjust its clock speed under program control.