Accurate direction-of-arrival (DOA) estimation of wideband signals in complex propagation environments remains a fundamental and challenging problem. This paper presents a comparative study of six wideband DOA estimation methods–IMUSIC (Incoherent Multiple Signal Classification), TOFS (Test of Orthogonality of Frequency Subspaces), MTOFS (Modified TOFS), TOPS (Test of Orthogonality of Projected Subspaces), S-TOPS (Squared TOPS), and WAVES (Weighted Average of Signal Subspaces)–applied for the first time to 2D azimuth estimation using a Uniform Circular Array (UCA). Simulations are performed under realistic and challenging conditions, including a limited number of sensors, high noise levels, and a small number of snapshots. Performance is evaluated using the Root Mean Square Error (RMSE) of DOA estimates as a function of the Signal-to-Noise Ratio (SNR) and source angular separation. The results demonstrate the robustness and high angular resolution of the advanced methods, particularly MTOFS, WAVES, and IMUSIC, applied to 2D UCAs, confirming their effectiveness for accurate source localization in complex environments.
Despite its nucleon numbers not coinciding with the traditional nuclear magic numbers, the structure of Ca 54 shows signatures of a doubly closed shell nucleus. This article details the structures of neutron-excited states up to beyond the two-neutron emission threshold populated by the Ca 55 ( p , p n ) reaction at ∼ 200 MeV/nucleon. Level energies and population cross sections were determined through γ -ray spectroscopy and invariant-mass spectroscopy of Ca 54 . Large-scale shell model calculations with protons and neutrons allowed to occupy the s d − p f − s d g orbitals were performed to predict energy levels and spectroscopic factors. Distorted wave impulse approximation calculations provided single-particle knockout cross sections and momentum distributions of the reaction products. The theoretical calculations reproduce the data well. Both theory and experiment are suggestive of a well-preserved shell structure at high excitation energy. Also, inelastic scattering of Ca 54 , carried out within the same experiment, validates previously proposed level schemes.
Neural Architecture Search (NAS) automates network design, but evaluating a single candidate requires training it to convergence, making exhaustive search intractable. Zero-cost proxies estimate architecture quality at initialization in seconds, yet a single proxy is noisy, and combining several does not straightforwardly help: proxies are strongly correlated, so naive aggregation compounds their shared errors instead of averaging them out. Existing methods exploit either proxy signals or architectural topology - never both within a single active-learning framework. We introduce ZAPS (Zero-cost Active Proxy Search), a four-stage pipeline that closes this gap. ZAPS (i) selects a compact, non-redundant proxy subset offline via ProxyFit, a greedy anti-redundancy criterion; (ii) seeds the search with a hybrid K-means strategy that balances exploitation and exploration; (iii) re-selects proxies at every iteration by a bootstrapped vote as the labeled set grows; and (iv) ranks candidates with an XGBoost ensemble trained jointly on proxy ranks and one-hot topological encodings, queried through an Upper Confidence Bound (UCB) acquisition function. On NAS-Bench-201 under a budget of B=200 evaluations, ZAPS recovers 52.3
In this article, a new methodology is proposed for MOSFET parameter extraction and modeling of transfer behavior from weak to strong inversion range in ohmic operation at cryogenic temperatures. The propounded methodology is based on an empirical mobility law which considers that the Coulomb scattering mechanism prevails in weak inversion, while it is the surface roughness mechanism in strong inversion at temperatures lower than 30K. It permits to extraction of the inversion charge from weak to strong inversion range through I - V measurements. It appears that the estimated inversion charge behavior may concur with the one analytically constructed using the Lambert-W function approach. The new methodology can be employed when the conventional mobility law, through a negative first-order intrinsic mobility attenuation factor, fails to model the Coulomb scattering mechanism in weak inversion at very cryogenic temperatures.
