Unsupervised Triplet Hashing for Fast Image Retrieval

Hashing has played a pivotal role in large-scale image retrieval. With the development of Convolutional Neural Network (CNN), hashing learning has shown great promise. But existing methods are mostly tuned for classification, which are not optimized for retrieval tasks, especially for instance-level retrieval. In this study, we propose a novel hashing method for large-scale image retrieval. Considering the difficulty in obtaining labeled datasets for image retrieval task in large scale, we propose a novel CNN-based unsupervised hashing method, namely Unsupervised Triplet Hashing (UTH). The unsupervised hashing network is designed under the following three principles: 1) more discriminative representations for image retrieval; 2) minimum quantization loss between the original real-valued feature descriptors and the learned hash codes; 3) maximum information entropy for the learned hash codes. Extensive experiments on CIFAR-10, MNIST and In-shop datasets have shown that UTH outperforms several state-of-the-art unsupervised hashing methods in terms of retrieval accuracy

Micro/nano-structural evolution in blended cement paste due to progressive deionised water leaching

This study investigates the structural evolution of the blended cement pastes at micro-, nano-, and atomic-scale due to environmental factors, such as, water leaching, ageing and curing temperature, with the aid of the analytical techniques, i.e. thermal analysis, XRD, SEM, TEM and SS MAS NMR. The water leaching experiments are performed on the one year old WPC cement paste blended with 30% PFA, as well as 13 years old WPC cement paste blended with 30% and 50% PFA. It is observed that the water leaching induces the phase dissolution and precipitation, e.g. CH, anhydrous cement, AFm and TAH dissolution, C-S-H secondary formation and decalcification, AFt secondary formation and dissolution. The microstructure of the cement paste changes from compact feature to dry cracked land like feature. The Op C-S-H transfers from fine fibrillar or foil-like feature to three dimensional net like feature, and the porosity of Ip C-S-H has increased. The aluminosilicate structure changes from single chain to double chain as the chains have cross-linked across the interlayer. It is also observed with higher replacement of PFA, the leaching speed is slower. Additionally, it is observed the chemical composition, the micro- and nano-scale structure evolve with ageing. The effects of curing temperature on OPC:BFS blended cement hydration is studied. It is found that as curing temperature increases: the general microstructure of the cement paste becomes more porous; more slag reacts, and more Ip C-S-H with high Al and Mg forms; and the MCL of aluminosilicate anion chain increases. For comparison, synthetic C-A-S-H is also characterized to better understand the structure of the C-A-S-H in the cement paste, especially the atomic-scale structure

Protocol for dissecting cascade computational components in neural networks of a visual system

Finding the complete functional circuits of neurons is a challenging problem in brain research. Here, we present a protocol, based on visual stimuli and spikes, for obtaining the complete circuit of recorded neurons using spike-triggered nonnegative matrix factorization. We describe steps for data preprocessing, inferring the spatial receptive field of the subunits, and analyzing the module matrix. This approach identifies computational components of the feedforward network of retinal ganglion cells and dissects the network structure based on natural image stimuli.For complete details on the use and execution of this protocol, please refer to Jia et al. (2021).

Review on the Status Quo of China’s Cross-border E-commerce Research Based on Bibliometrics

This paper used Bibexcel, Netdraw and other software to obtain the bibliographic data of the literature, sourcing from CSSCI journals of China national knowledge infrastructure, in order to isolate the major academic groups of cross-border e-commerce and explore the evolution of keywords over the years. Also, the paper drew knowledge mapping according to the word frequency statistics and used keyword co-occurrence methods to investigate research topics and hotspots and clarified possible research trends. Results indicated that the number of cross-border e-commerce research achievements had grown rapidly, and the research themes primarily could be divided into six orientations. The study on cross-border e-commerce along the ‘Belt and Road’ countries has been increasing year by year. Furthermore, the research process should strengthen interdisciplinary cooperation and the level of theoretical innovation should be improved

The Design and Implementation of Mobile Monitoring System of Transmitting Station Based on Android Platform

AbstractIn view of the high speed development of current mobile platform related technology and wireless telecommunication technology, this paper designs and realized a radio and television launching pad mobile monitoring system based on Android platform. The system as expansion of the present scene monitoring system to receive real-time data on transmitters and control their states by wireless network at any time and place, thus further improve the operation efficiency of transmitting station

CERKL regulates autophagy via the NAD-dependent deacetylase SIRT1

<p>Macroautophagy/autophagy is an important intracellular mechanism for the maintenance of cellular homeostasis. Here we show that the <i>CERKL</i> (ceramide kinase like) gene, a retinal degeneration (RD) pathogenic gene, plays a critical role in regulating autophagy by stabilizing SIRT1. <i>In vitro</i> and <i>in vivo</i>, suppressing CERKL results in impaired autophagy. SIRT1 is one of the main regulators of acetylation/deacetylation in autophagy. In CERKL-depleted retinas and cells, SIRT1 is downregulated. ATG5 and ATG7, 2 essential components of autophagy, show a higher degree of acetylation in CERKL-depleted cells. Overexpression of SIRT1 rescues autophagy in CERKL-depleted cells, whereas CERKL loses its function of regulating autophagy in SIRT1-depleted cells, and overexpression of CERKL upregulates SIRT1. Finally, we show that CERKL directly interacts with SIRT1, and may regulate its phosphorylation at Ser27 to stabilize SIRT1. These results show that CERKL is an important regulator of autophagy and it plays this role by stabilizing the deacetylase SIRT1.</p

The Design, Practice and Effects of a SPOC

The 2022 “Frontier of Educational Technology” summer school was held by the Department of Educational Technology, Graduate School of Education, Peking University from July 4th 2022 to July 8th 2022. In order to ensure the learning quality, a small private online course was designed for the first time. A series of learning activities such as ice-breaking trip, expert lectures, group discussions, and group presentation were carried out with the help of the course management system, live broadcast platform and social media groups. We analyzed the data recorded by the course management system and found that more than half of the students participated in all learning activities, and the final completion rate of the summer school is as high as 89.86%. An online questionnaire was used to examine students’ subjective responses to the pedagogy and course performance. The results showed that the average score of almost all the questions in the questionnaire is greater than 4.3 points (out of 5.0), indicating that most students are satisfied or very satisfied with this pedagogy. Suggestions for improvement and future expectations are put forward, and can provide a reference for the full-online SPOC practice and research that are being widely carried out around the world