Abstract: Disclosed herein is a program conversion apparatus, which converts a first program to which homomorphic encryption is not applied into a second program to which the homomorphic encryption is applied, including a memory, which stores a first library for configuring the first program and a second library for configuring the second program, and a processor configured to convert the first program into the second program through conversion between operations provided by the first and second libraries.

Abstract: A filter medium, a filter into which the filter medium is installed, and an apparatus for supplying air and chemicals equipped with the filter. The filter medium has a sheet including a first pleated portion, which is folded in a first wave shape such that a first amplitude and a first wave length are formed in the first pleated portion. The filter medium also includes a second pleated portion, which is folded in a second wave shape such that a second amplitude, less than the first amplitude, and a second wave length, shorter than the first wave length, are formed in the second pleated portion. At least one second pleated portion is formed in the first pleated portion.