For KeyGen is used Hamming weight is exactly h. I do not understand how to define h

The Hamming weight for a given security level depends on the ring dimension and ciphertext modulus Q. See On the Feasibility and Impact of Standardising Sparse-secret LWE Parameter Sets for Homomorphic Encryption for more details (there are many other papers on the subject as well). In OpenFHE, we use the hamming weight of 192, which is sufficient for most of practical ring dimensions.

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