Hokkaido Research Organization

Unconditional Half-Density at Minimum 2-Class Depth in a Two-Prime Layer III+ Family

We prove unconditionally that the minimum-depth event (e=2) has limiting conditional density (1/2) in a two-prime Layer III+ family. The Layer III+ character sum is decomposed into four components. Three ancillary components are realized as tempered quadratic or cyclic-quartic ch...

Explicit 8-Rank Criteria in a Squarefree Composite Family: Rédei Kernels, Artin Symbols, and Continued-Fraction Centers

We study the narrow class group of real quadratic fields with fundamental discriminant D = 4AB, where A is a prime congruent to 7 modulo 8 and B = p₁p₂ is a product of two distinct primes lying either both in 1 modulo 8 or both in 7 modulo 8. A single four-bit formula is obtained...

Explicit 8-Rank Criteria in a Squarefree Composite Family: Rédei Kernels, Artin Symbols, and Continued-Fraction Centers

We study the narrow class group of real quadratic fields with fundamental discriminant D = 4AB, where A is a prime congruent to 7 modulo 8 and B = p₁p₂ is a product of two distinct primes lying either both in 1 modulo 8 or both in 7 modulo 8. A single four-bit formula is obtained...

An eigenvalue decomposition based full polarimetric SAR framework for leaf area index retrieval using entropy-anisotropy features

Present study proposes a novel Full Polarimetric Radar Vegetation Index (FPRVI) for accurate Leaf Area Index (LAI) retrieval using RISAT-1A full-polarimetric SAR data. The eigenvalue-based polarimetric decomposition parameters entropy (H) and anisotropy (A) have been employed to...

The Jacobi-positive squarefree odd semiprimes: a complete parametrisation

Let N = ℓM with 3 ≤ ℓ < M distinct odd primes and let 𝒥(N) be the set of denominators Q_k in the period of the continued fraction of √N whose Jacobi symbol (Q_k/N) equals +1. A previous paper (DOI 10.5281/zenodo.21285697) proved that 𝒥(N) = {1} forces the period length L to lie i...