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トリデンテンはY字芳香族化合物におけるアヌレンに相当する物質として，筆者によって提案された． この解説では，ヒュッケルの4N+2則に相当するトリデンテンの魔法数に関する議論と，立体選択的な包摂作用を実現するイオン流体を構成することが期待できるタイフーントリデンテンとサイクロントリデンテンの議論を，既発表の論文に最新の情報を加え，改訂・再構成して紹介する。, As substances corresponding to annulenes in Y-aromatic compounds, tridentenes were proposed by the authors. In this description, by revision of existing papers, a discussion on the magic number of tridentenes, which corresponds to Hückel’s 4N+2 rule, and arguments regarding typhoon tridentene and cyclone tridentene, which are expected to have stereoselective inclusion forming ability, are presented.

For scenarios of coherent underwater sources at low signal-to-noise ratio (SNR), a novel quaternion-based DOA algorithm without eigendecomposition is proposed using a linear vector-hydrophone array. We construct four quaternion models by judiciously arranging the received data to fully utilize the statistical information of the incident signals. To avoid the high computational complexity caused by the eigenvalue decomposition (EVD), we introduce the computationally efficient propagator method (PM) to estimate the elevation angles of the observed signals. In the quaternion algebra framework, we statistically eliminate the additive noise, which makes the PM method exhibit a robust performance in low SNR. By fully exploiting the direction information embedded in the velocity components, we achieve a high-resolution two-dimensional (2-D) DOA estimation result with a linear vector-hydrophone array. The simulations demonstrate that the proposed method offers stable estimation performance compared with the existing non-quaternion schemes without the need for any pair matching between the estimated azimuth and elevation angles.

A frequency diverse array (FDA) multiple‐input multiple‐output (MIMO) radar employs a small frequency increment across transmit elements to produce an angle‐range‐dependent beampattern for target angle and range detection. The joint angle and range estimation problem is a trilinear model. The traditional trilinear alternating least square (TALS) algorithm involves high computational load due to excessive iterations. We propose a fast‐convergence trilinear decomposition (FC‐TD) algorithm to jointly estimate FDA‐MIMO radar target angle and range. We first use a propagator method to obtain coarse angle and range estimates in the data domain. Next, the coarse estimates are used as initialized parameters instead of the traditional TALS algorithm random initialization to reduce iterations and accelerate convergence. Finally, fine angle and range estimates are derived and automatically paired. Compared to the traditional TALS algorithm, the proposed FC‐TD algorithm has lower computational complexity with no estimation performance degradation. Moreover, Cramér‐Rao bounds are presented and simulation results are provided to validate the proposed FC‐TD algorithm effectiveness.

A numerical technique to calculate real-space electron transport coefficients in gas under crossed electric and magnetic fields ( $E \times B$ fields) by the propagator method (PM) was newly developed. Components of a centroid drift velocity vector of an electron swarm and its diffusion coefficients defined in the $E$ , $B$ , and $E \times B$ directions were calculated by applying the PM stepwise to the zeroth-, first-, and second-order $x$ , $y$ , and $z$ spatial moment equations derived from the Boltzmann equation. The results calculated for SF6 at $N = 10^{22}\,\,\text{m}^{-3}$ in $E/N$ and $B/N$ ranges of 100–1000 Td and 100–1000 Hx, respectively, agreed with those obtained by Monte Carlo simulations with discrepancies of a few percent. The Hall deflection of the drift velocity vector and the direction dependence of the diffusion coefficients were appropriately reproduced. A relaxation scheme developed for quick convergence of the electron velocity distribution function was effective also in the relaxations of the first- and second-order spatial moment distribution functions. A prototype of the PM as a calculation scheme to derive a set of electron transport coefficients necessary for fluid model simulations of magnetized plasmas was established.

A matrix-based calculation for the electron velocity distribution function (EVDF) in gas under dc electric field is demonstrated. The propagator matrix power method (PMPM) repeats squaring the propagator matrix P for its powers P 2, P 4, P 8, P 16, ⋯, up to a sufficient order of the power P 2 S . P is a square matrix representing the change of EVDF due to the electron acceleration by an electric field and the electron scattering by gas molecules in a time step Δt. With an initial EVDF f(t 0) in a form of a column vector, a matrix product P 2 S f ( t 0 ) gives the EVDF at t = t 0 + 2 S Δt. The PMPM enables us to observe the EVDF relaxation in a logarithmic time scale with a linear increase of the matrix squaring steps S. Features of the PMPM are discussed, and theoretically possible extensions to models under crossed electric and magnetic fields and ac electric field are investigated.

International audience; Massive MIMO technology, considered as one of thefifth generation (5G) system candidates, has been more andmore important in research.The direction of arrival(DOA)estimation is closely related with massive MIMO system.Hence, a precise and low computational method to estimateDOA of the signals is necessary. In this paper,we extended thesignal model in a 2D problem with a plane antenna array andproposed an improvements of Propagator method(PM).Basedon root MUSIC method, the angle parameter can be estimatedby another angle parameter. It does not need to reconstructionof the system model and achieve automatic pairing. So thismethod can reduce the computational complexity significantlyand has well performance in low SNR condition.

7 pags.; 7 figs., LOWDIN is a computational program that implements the Any Particle Molecular Orbital (APMO) method. The current version of the code encompasses Hartree-Fock, second-order Møller-Plesset, configuration interaction, density functional, and generalized propagator theories. LOWDIN input file offers a unique flexibility, allowing users to exploit all the programs' capabilities to study systems containing any type and number of quantum species. This review provides a basic introduction to LOWDIN's key computational details and capabilities. © 2013 Wiley Periodicals, Inc. LOWDIN is a versatile computational program that implements the any particle molecular orbital (APMO) method. In the APMO framework, typical electronic structure methodologies are extended to any type of quantum particle. With the LOWDIN program, systems containing any type and number of quantum species can be studied. Copyright © 2013 Wiley Periodicals, Inc., Contract grant sponsor: Universidad Nacional; contract grant numbers: DIB-201010018545 and DIB-201010016739 (to AR).Contract grant sponsor: SEP-CONACYT (Mexico); contract grant number:127362 (to RFM).Contract grant sponsor: CONACYT; contract grant number: 257420 (toMAD).