387 research outputs found
Teaching Practice about Flipped Classroom on Circuit Course
In view of the problems in circuit course, flipped classroom is introduced and new teaching mode is explored. Teaching design, teaching reform suggestion, teaching effects and results are presented. It is verified that this kind of teaching mode can enhance the enthusiasm, initiative and participation of the students, teaching efficiency is also improved. It is also a good way for comprehensive practice
The Relationships Between the Level of Lignin, a Secondary Metabolite in Soybean Plant, and Aphid Resistance in Soybeans
In the present report, the relationship was discussed between the level of lignin-one of the secondary metabolites in soybean plant and the chemical defense reaction of soybean to the soybean aphid (Aphis glycines Muts). Experimental results indicated that the cultivars with higher level of lignin are more resistant to the damage of aphids than those with lower level of lignin. Lignin is one of the compounds that are responsible to the chemical defense reaction of soybean. This finding laid a foundation for the elucidation of the mechanism of aphid resistance in plants and its biochemical basis.Originating text in Chinese.Citation: Hu, Qi, Zhao, Jianwei, Cui, Jianwen. (1993). The Relationships Between the Level of Lignin, a Secondary Metabolite in Soybean Plant, and Aphid Resistance in Soybeans. Plant Protection (Institute of Plant Protection, CAAS, China), 19(1), 8-9
NegDL: Privacy-Preserving Deep Learning Based on Negative Database
In the era of big data, deep learning has become an increasingly popular
topic. It has outstanding achievements in the fields of image recognition,
object detection, and natural language processing et al. The first priority of
deep learning is exploiting valuable information from a large amount of data,
which will inevitably induce privacy issues that are worthy of attention.
Presently, several privacy-preserving deep learning methods have been proposed,
but most of them suffer from a non-negligible degradation of either efficiency
or accuracy. Negative database (\textit{NDB}) is a new type of data
representation which can protect data privacy by storing and utilizing the
complementary form of original data. In this paper, we propose a
privacy-preserving deep learning method named NegDL based on \textit{NDB}.
Specifically, private data are first converted to \textit{NDB} as the input of
deep learning models by a generation algorithm called \textit{QK}-hidden
algorithm, and then the sketches of \textit{NDB} are extracted for training and
inference. We demonstrate that the computational complexity of NegDL is the
same as the original deep learning model without privacy protection.
Experimental results on Breast Cancer, MNIST, and CIFAR-10 benchmark datasets
demonstrate that the accuracy of NegDL could be comparable to the original deep
learning model in most cases, and it performs better than the method based on
differential privacy
CoopHash: Cooperative Learning of Multipurpose Descriptor and Contrastive Pair Generator via Variational MCMC Teaching for Supervised Image Hashing
Leveraging supervised information can lead to superior retrieval performance
in the image hashing domain but the performance degrades significantly without
enough labeled data. One effective solution to boost the performance is to
employ generative models, such as Generative Adversarial Networks (GANs), to
generate synthetic data in an image hashing model. However, GAN-based methods
are difficult to train and suffer from mode collapse issue, which prevents the
hashing approaches from jointly training the generative models and the hash
functions. This limitation results in sub-optimal retrieval performance. To
overcome this limitation, we propose a novel framework, the generative
cooperative hashing network (CoopHash), which is based on the energy-based
cooperative learning. CoopHash jointly learns a powerful generative
representation of the data and a robust hash function. CoopHash has two
components: a top-down contrastive pair generator that synthesizes contrastive
images and a bottom-up multipurpose descriptor that simultaneously represents
the images from multiple perspectives, including probability density, hash
code, latent code, and category. The two components are jointly learned via a
novel likelihood-based cooperative learning scheme. We conduct experiments on
several real-world datasets and show that the proposed method outperforms the
competing hashing supervised methods, achieving up to 10% relative improvement
over the current state-of-the-art supervised hashing methods, and exhibits a
significantly better performance in out-of-distribution retrieval
Single image super resolution based on multi-scale structure and non-local smoothing
In this paper, we propose a hybrid super-resolution method by combining global and local dictionary training in the sparse domain. In order to present and differentiate the feature mapping in different scales, a global dictionary set is trained in multiple structure scales, and a non-linear function is used to choose the appropriate dictionary to initially reconstruct the HR image. In addition, we introduce the Gaussian blur to the LR images to eliminate a widely used but inappropriate assumption that the low resolution (LR) images are generated by bicubic interpolation from high-resolution (HR) images. In order to deal with Gaussian blur, a local dictionary is generated and iteratively updated by K-means principal component analysis (K-PCA) and gradient decent (GD) to model the blur effect during the down-sampling. Compared with the state-of-the-art SR algorithms, the experimental results reveal that the proposed method can produce sharper boundaries and suppress undesired artifacts with the present of Gaussian blur. It implies that our method could be more effect in real applications and that the HR-LR mapping relation is more complicated than bicubic interpolation
Chiral Brønsted acid catalyzed enantioselective dehydrative Nazarov-type electrocyclization of aryl and 2-Thienyl vinyl alcohols
An efficient chiral Brønsted acid-catalyzed enantioselective dehydrative Nazarov-type electrocyclization (DNE) of electron-rich aryl- and 2-thienyl-β-amino-2-en-1-ols is described. The 4π conrotatory electrocyclization reaction affords access to a wide variety of the corresponding 1H-indenes and 4H-cyclopenta[b]thiophenes in excellent yields of up to 99% and enantiomeric excess (ee) values of up to 99%. Experimental and computational studies based on a proposed intimate contact ion-pair species that is further assisted by hydrogen bonding between the amino group of the substrate cation and chiral catalyst anion provide insight into the observed product enantioselectivities
Fracture failure analysis and bias tearing strength criterion for PVDF coated bi-axial warp knitted fabrics
This paper concerns the fracture failure and bias tearing strength criterion for a PVDF coated bi-axial warp knitted fabrics (BWKFs) widely used in air supported membrane structures (ASMSs). Central slit tearing tests were carefully conducted on bias specimens with seven off-axis angles, and the corresponding tearing properties, including failure behaviors and tearing strength criterion were discussed. Results show that coated bi-axial warp knitted fabrics are typical direction-depended materials, and their tearing characteristics vary greatly with the bias angles. Typical tearing stress-displacement curves of bias samples could exhibit four characteristic regions: a co-deformation region, a shear deformation region, a plateau region, and a post peak region. No matter what the orientation of the initial slit or the yarn is, the propagation is always parallel to the secondary yarns. For specimens with different bias angles, some obvious differences in tearing behaviors are observed in terms of maximum displacement, damage mode, curve slope, and number of stress peaks, and these differences could be attributed to the material orthotropy and different failure mechanism of constituent materials. Unlike results of tensile strength for most of woven fabrics, for the studied BWKF composite, there is a W-shaped relationship between tearing strength and bias angle, with a local strength peak at 45o angle. The new tearing strength criterion proposed in the prior research is validated due to the strong agreements between the calculated and experimental results for the BWKF
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