Coevolutionary particle swarm optimization using AIS and its application in multiparameter estimation of PMSM

In this paper, a coevolutionary particle-swarm-optimization (PSO) algorithm associating with the artificial immune principle is proposed. In the proposed algorithm, the whole population is divided into two kinds of subpopulations consisting of one elite subpopulation and several normal subpopulations. The best individual of each normal subpopulation will be memorized into the elite subpopulation during the evolution process. A hybrid method, which creates new individuals by using three different operators, is presented to ensure the diversity of all the subpopulations. Furthermore, a simple adaptive wavelet learning operator is utilized for accelerating the convergence speed of the pbest particles. The improved immune-clonal-selection operator is employed for optimizing the elite subpopulation, while the migration scheme is employed for the information exchange between elite subpopulation and normal subpopulations. The performance of the proposed algorithm is verified by testing on a suite of standard benchmark functions, which shows faster convergence and global search ability. Its performance is further evaluated by its application to multiparameter estimation of permanent-magnet synchronous machines, which shows that its performance significantly outperforms existing PSOs. The proposed algorithm can estimate the machine dq-axis inductances, stator winding resistance, and rotor flux linkage simultaneously. © 2013 IEEE

Transition-metal-free synthesis of thiocyanato- or nitro-arenes through diaryliodonium salts

<p>A transition-metal-free approach to facile synthesis of thiocyanato- and nitro-arenes was developed from KSCN (potassiumthiocyanate) or NaNO₂ with diaryliodonium salts in good yields under mild conditions. The reaction was compatible with a variety of sensitive functional substituents such as halides and nitro and ester groups. The usefulness of arylation products has been realized.</p

An enhanced approach for parameter estimation: using immune dynamic learning swarm optimization based on multicore architecture

The identification of physical parameters is crucial for control system designs, condition monitoring and fault diagnosis of industrial drive systems. The article brings multicore architecture based parallel computing technology and bioinspired intelligent optimisation algorithm insight into designing for system parameter estimation models.models. In this study, a parallel implementation using an immune-cooperative dynamic learning particle swarm optimization (PSO) algorithm with multicore computation architectures is presented for permanent magnet synchronous machine (PMSM) parameter estimations. Three novel strategies are discussed, all with the purpose of enhancing the dynamic response and fast convergence performance of the designed parameter estimator. The strategies include a dynamic velocity modification strategy, an immune-memory-based searched information preservation mechanism, and an immune-network-based learning operator for PSO. Finally, a proposed method is applied to the parameter estimations of PMSMs as well as parallel running on multicore central processing units (CPU)

GPU-accelerated parallel coevolutionary algorithm for parameters identification and temperature monitoring in permanent magnet synchronous machines

A hierarchical fast parallel co-evolutionary immune particle swarm optimization (PSO) algorithm, accelerated by graphics processing unit (GPU) technique (G-PCIPSO), is proposed for multiparameter identification and temperature monitoring of permanent magnet synchronous machines (PMSM). It is composed of two levels and is developed based on compute unified device architecture (CUDA). In G-PCIPSO, the antibodies (Abs) of higher level memory are selected from the lower level swarms and improved by immune clonal-selection operator. The search information exchanges between swarms using the memory-based sharing mechanism. Moreover, an immune vaccine-enhanced operator is proposed to lead the Pbests particles to unexplored areas. Optimized parallel implementations of G-PCIPSO algorithm is developed on GPU using CUDA, which significantly speeds up the search process. Finally, the proposed algorithm is applied to multiple parameters identification and temperature monitoring of PMSM. It can track parameter variation and achieve temperature monitoring online effectively. Compared with a CPU-based serial execution, the computational efficiency is greatly enhanced by GPU-accelerated parallel computing technique

Stereoselective Radical Cyclization Cascades Triggered by Addition of Diverse Radicals to Alkynes To Construct 6(5)–6–5 Fused Rings

Cascade radical cyclization of alkynyl ketones with various carbon- and heteroatom-centered radical precursors via a sequential radical addition/1,5-H radical shift/5-<i>exo-trig</i>/radical cyclization process was realized for the first time. This method provides a strategically novel and step-economical protocol for diversity-oriented synthesis of a wide range of carbocyclic and heterocyclic 6(5)–6–5 fused ring systems with three contiguous stereocenters, including a quaternary carbon in high yields with excellent chemo- and diastereoselectivity

Blue Phosphorus/Mg(OH)₂ van der Waals Heterostructures as Promising Visible-Light Photocatalysts for Water Splitting

To construct efficient solar-driven devices, considerable efforts have been made to search for desirable photocatalysts for water splitting. Motivated by recent successful syntheses of single-layer blue phosphorus (BlueP) and Mg­(OH)₂, we systematically investigate the stability, energy band structure, charge transfer, and potential photocatalytic properties of the BlueP/Mg­(OH)₂ van der Waals heterostructure using the first-principles method. It is found that all the heterostructures considered possess similar electronic and optical properties and exhibit type-II band alignment and indirect band gap characteristics. In addition, the ground-state configuration (β-stacking) of the heterostructure is found to be a potential photocatalyst for water splitting. In particular, its band gap, band-edge positions, and optical absorption can be tuned by in-layer biaxial strain to improve the efficiency of the photocatalytic water splitting. Our findings provide a new possibility of designing efficient photocatalysts for water splitting

Synthesis of <i>N</i>‑(2-Hydroxyaryl)benzotriazoles via Metal-Free <i>O</i>‑Arylation and N–O Bond Cleavage

A metal-free method for synthesis of <i>N</i>-(2-hydroxyaryl)­benzotriazoles via <i>O</i>-arylation of <i>N</i>-hydroxybenzotriazoles with readily available diaryliodonium salts and sequential N–O bond cleavage under mild conditions has been developed. The [3,3]-rearrangement of N–O bond cleavage could take place on the N instead of C atom. The reaction was compatible with diverse functional groups and a new type of <i>P</i>,<i>N</i>-ligand was synthesized in three steps

Isochromanes from <i>Aspergillus fumigatus</i>, an endophytic fungus from <i>Cordyceps sinensis</i>

<p>Four previously undescribed isochromanes were isolated from the fermentation broth of an endophytic fungus <i>Aspergillus fumigatus</i>, which was obtained from the fruiting body of <i>Cordyceps sinensis</i>. Their structures were elucidated through extensive spectroscopic analyses. One racemic isochromane was further purified by chiral HPLC to yield a pair of enantiomers and their absolute configurations were determined by quantum chemical ECD calculations. These isolated compounds were evaluated for cytotoxicity against two cell lines (MV4-11 and MDA-ME-231) and the result showed that compounds <b>1a</b> and <b>2</b> exhibited moderate growth inhibition against MV4-11 cell line.</p

Aryl-tetralin-type lignan isolated from <i>Sanguisorba officinalis</i>

<p>Three aryl-tetralin-type lignans, including 2 previously undescribed compounds, were isolated from the root of <i>Sanguisorba officinalis</i>. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic analyses and mass spectrometry. Experimental and calculated ECD were used to determine the absolute configurations. The isolated compounds were evaluated for cytotoxicity against two cell lines (MV4-11 and MDA-MB-231) and compound <b>1</b> exhibited moderate growth inhibition against MDA-MB-231 cell line with IC₅₀ value of 15.76 μM.</p

Synthesis of α,β-Unsaturated <i>N</i>‑Aryl Ketonitrones from Oximes and Diaryliodonium Salts: Observation of a Metal-Free <i>N</i>‑Arylation Process

An efficient transition-metal-free method for the preparation of α,β-unsaturated <i>N</i>-aryl ketonitrones under mild conditions has been developed. This reaction shows good functional group tolerance for both electron-rich and electron-deficient substituents on both oximes and diaryliodonium salts. Two examples of gram-scale preparations have been realized in good yields. Further transformations of these nitrones to different <i>N</i>-heterocycles have been demonstrated. DFT calculations suggest that <i>N</i>-arylation products are formed by [1,3]-phenyl migration of an <i>O</i>-coordinated oximate complex via a four-centered transition state, while the <i>O</i>-arylation products are formed by [1,3]-phenyl migration of a <i>N</i>-coordinated oximate complex