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1.
J Org Chem ; 88(13): 8969-8983, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37345284

RESUMO

A mild and greener approach for intramolecular regioselective hydroarylation is described for the efficient and elegant preparation of a number of dihydrobenzofurans and dihydrobenzo[b]thiophenes using imidazole as a directing group and Rh(III) as a catalyst. Moreover, the protocol may be extended to the formation of indoline and chromane derivatives. Deuterium scrambling experiments and characterization of isolated rhodacycle intermediate were explored to understand the mechanism in a better way.


Assuntos
Ródio , Metanol , Catálise , Imidazóis
2.
Evol Comput ; : 1-25, 2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37155646

RESUMO

Evolution-based neural architecture search methods have shown promising results but they require high computational resources since these methods involve training each candidate architecture from scratch and then evaluating its fitness which results in long search time. Covariance Matrix Adaptation Evolution Strategy (CMA-ES) has shown promising results in tuning hyperparameters of neural networks but has not been used for neural architecture search. In this work, we propose a framework called CMANAS which applies the faster convergence property of CMA-ES to the deep neural architecture search problem. Instead of training each individual architecture seperately, we used the accuracy of a trained one shot model (OSM) on the validation data as a prediction of the fitness of the architecture resulting in reduced search time. We also used an architecture-fitness table (AF table) for keeping record of the already evaluated architecture, thus further reducing the search time. The architectures are modelled using a normal distribution, which is updated using CMA-ES based on the fitness of the sampled population. Experimentally, CMANAS achieves better results than previous evolution-based methods while reducing the search time significantly. The effectiveness of CMANAS is shown on 2 different search spaces for datasets: CIFAR-10, CIFAR-100, ImageNet and ImageNet16-120. All the results show that CMANAS is a viable alternative to previous evolution-based methods and extends the application of CMA-ES to the deep neural architecture search field.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31885653

RESUMO

In this article, a three-dimensional pulse image (3DPI) instead of a one-dimensional temporal pulse wave is studied to elucidate its spatiotemporal characteristics. To check the spatial and temporal properties of 3DPI, adopted is Fourier series, in which a ratio (r) is defined as one amplitude divided by the sum of the first three amplitudes of harmonics. A ratio sequence is constituted from 70 to 90 ratios in a heartbeat with 70-90 3DPIs by sampling. Twenty-four subjects (14 males and 10 females with age of 22.2 ± 3.7 years, 20.4 ± 1.4 BMI, and 112.1 ± 4.7 mmHg systolic blood pressure) are involved in this research. There are significant statistical differences in the groups of the normal, taut, and slippery 3DPIs by the first harmonic ratio average ( r 1 ¯ ) and ratio difference (Δr 1) produced from the ratio sequence. The proposed method of this study gives us a novel viewpoint to clarify the spatiotemporal characteristics of pulse images, which can translate and quantize the pulse feeling in Chinese medicine texts.

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