@article{li_song_wu_2019, title={AOGNets: Compositional Grammatical Architectures for Deep Learning}, ISSN={["1063-6919"]}, DOI={10.1109/CVPR.2019.00638}, abstractNote={Neural architectures are the foundation for improving performance of deep neural networks (DNNs). This paper presents deep compositional grammatical architectures which harness the best of two worlds: grammar models and DNNs. The proposed architectures integrate compositionality and reconfigurability of the former and the capability of learning rich features of the latter in a principled way. We utilize AND-OR Grammar (AOG) as network generator in this paper and call the resulting networks AOGNets. An AOGNet consists of a number of stages each of which is composed of a number of AOG building blocks. An AOG building block splits its input feature map into N groups along feature channels and then treat it as a sentence of N words. It then jointly realizes a phrase structure grammar and a dependency grammar in bottom-up parsing the “sentence” for better feature exploration and reuse. It provides a unified framework for the best practices developed in state-of-the-art DNNs. In experiments, AOGNet is tested in the ImageNet-1K classification benchmark and the MS-COCO object detection and segmentation benchmark. In ImageNet-1K, AOGNet obtains better performance than ResNet and most of its variants, ResNeXt and its attention based variants such as SENet, DenseNet and DualPathNet. AOGNet also obtains the best model interpretability score using network dissection. AOGNet further shows better potential in adversarial defense. In MS-COCO, AOGNet obtains better performance than the ResNet and ResNeXt backbones in Mask R-CNN.}, journal={2019 IEEE/CVF CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION (CVPR 2019)}, author={Li, Xilai and Song, Xi and Wu, Tianfu}, year={2019}, pages={6213–6223} }
 @article{duan_li_li_semenov_kim_2015, title={Highly efficient conductance control in a topological insulator based magnetoelectric transistor}, volume={118}, ISSN={0021-8979 1089-7550}, url={http://dx.doi.org/10.1063/1.4937407}, DOI={10.1063/1.4937407}, abstractNote={The spin-momentum interlocked properties of the topological insulator (TI) surface states are exploited in a transistor-like structure for efficient conductance control in the TI-magnet system. Combined with the electrically induced magnetization rotation as part of the gate function, the proposed structure takes advantage of the magnetically modulated TI electronic band dispersion in addition to the conventional electrostatic barrier. The transport analysis coupled with the magnetic simulation predicts super-steep current-voltage characteristics near the threshold along with the GHz operating frequencies. Potential implementation to a complementary logic is also examined. The predicted characteristics are most suitable for applications requiring low power or those with small signals.}, number={22}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Duan, Xiaopeng and Li, Xi-Lai and Li, Xiaodong and Semenov, Yuriy G. and Kim, Ki Wook}, year={2015}, month={Dec}, pages={224502} }
 @article{duan_li_semenov_kim_2015, title={Nonlinear magnetic dynamics in a nanomagnet–topological insulator heterostructure}, volume={92}, ISSN={1098-0121 1550-235X}, url={http://dx.doi.org/10.1103/PhysRevB.92.115429}, DOI={10.1103/physrevb.92.115429}, abstractNote={Magnetization dynamics of a nanomagnet, when strongly coupled with a topological insulator (TI) via the proximity interaction, is examined theoretically in the presence of electrical current on the TI surface under realistic transport conditions. Due to the spin-momentum interlock, the magnetic state and TI electron transport depend significantly on each other. Such an interdependence leads to a variety of nonlinear dynamical responses in all transport regimes including the scattering dominant diffusive cases. Generation of the anomalous Hall current, in particular, is found to be a key to the unique features that have not been observed previously. For instance, the anomalous Hall current can result in antiparallel alignment of the final magnetization state in reference to the effective driving magnetic field by inducing an extra term that counters the damping effect. Similarly the calculation also reveals steady oscillation of the magnetization under a broad range of conditions, offering a robust mechanism for highly efficient magnetization reversal and/or spin wave excitation under a dc bias.}, number={11}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Duan, Xiaopeng and Li, Xi-Lai and Semenov, Yuriy G. and Kim, Ki Wook}, year={2015}, month={Sep} }