Abnormal Event Detection Based on Deep Autoencoder Fusing Optical Flow

International audienceAs an important research topic in computer vision, abnormal detection has gained more and more attention. In order to detect abnormal events effectively, we propose a novel method using optical flow and deep autoencoder. In our model, optical flow of the original video sequence is calculated and visualized as optical flow image, which is then fed into a deep autoencoder. Then the deep autoencoder extract features from the training samples which are compressed to low dimension vectors. Finally, the normal and abnormal samples gather separately in the coordinate axis. In the evaluation, we show that our approach outperforms the existing methods in different scenes, in terms of accuracy

Generative Neural Networks for Anomaly Detection in Crowded Scenes

International audienc

Composition Analysis of Sargassum Fusiforme in Different Marine Areas and Antioxidant Activity of Polysaccharides

Sargassum fusiforme is rich in a variety of nutrients and active substances, and is one of the important economic seaweeds in China. Its quality could be easily affected by environmental factors such as marine areas. To figure out the differences in nutritional composition of Sargassum fusiforme cultivated in different marine areas, this paper used Sargassum fusiforme cultivated in seven marine areas in Zhejiang Province as the research object, and determined the basic nutrients, amino acids and fatty acids using the National Food Safety Standard. The antioxidant activities of the seven Sargassum fusiforme polysaccharides were determined using DPPH· and ·OH scavenging as evaluation criteria, and the structural composition of seven kinds of Sargassum fusiforme polysaccharides were preliminarily analyzed. The results showed that, the moisture content of seven Sargassum fusiforme was highest, between (82.50±0.32) and (86.50±0.23) g/100 g. In addition to moisture content, the other main nutrient component was polysaccharide. The polysaccharide content of Sargassum fusiforme cultivated in No.7 marine area was the highest (P<0.05), which was 2.51 g/100 g. The fat content of Sargassum fusiforme of each marine area was relatively low, which was (0.30±0.01)~(0.40±0.01) g/100 g, indicating that Sargassum fusiforme was a kind of typically low-fat food. The amino acid content of Sargassum fusiforme varied greatly and the EAAI (Essential Amino Acid Index) values of Sargassum fusiforme in each marine area were all more than 0.9, indicating that Sargassum fusiforme in the seven marine areas were all high-quality protein sources. Furthermore, the amino acid composition ratios of Sargassum fusiforme cultivated in No.2 and No.6 marine areas were reasonable, which were closer to the ideal protein model recommended by WHO/FAO in 1937. A total of eight fatty acids were detected in Sargassum fusiforme from seven marine areas. Except for Sargassum fusiforme cultivated in No.2 marine area, the rest were mainly polyunsaturated fatty acids. The heavy metal content of Sargassum fusiforme complied with the requirements of in National food safety standard-Maximum levels of contaminants in foods (GB 2762-2017). The contents of Ca and K in Sargassum fusiforme cultivated in No.4 marine area were (131.44±6.36) mg/100 g and (1687.63±28.14) mg/100 g, respectively, which were good sources of Ca and K. The polysaccharide structures of Sargassum fusiforme in each marine area were similar, all of which contained sulfate groups and had the activity of scavenging ·OH and DPPH·. Among them, the polysaccharide of Sargassum fusiforme cultivated in No.5 marine area had the highest antioxidant activity, and the IC50 of scavenging ·OH and DPPH· were 0.534 and 0.236 mg/mL, respectively. This study laid a certain foundation for the scientific breeding, processing and quality grade evaluation of Sargassum fusiforme

ChatKBQA: A Generate-then-Retrieve Framework for Knowledge Base Question Answering with Fine-tuned Large Language Models

Knowledge Base Question Answering (KBQA) aims to derive answers to natural language questions over large-scale knowledge bases (KBs), which are generally divided into two research components: knowledge retrieval and semantic parsing. However, three core challenges remain, including inefficient knowledge retrieval, retrieval errors adversely affecting semantic parsing, and the complexity of previous KBQA methods. In the era of large language models (LLMs), we introduce ChatKBQA, a novel generate-then-retrieve KBQA framework built on fine-tuning open-source LLMs such as Llama-2, ChatGLM2 and Baichuan2. ChatKBQA proposes generating the logical form with fine-tuned LLMs first, then retrieving and replacing entities and relations through an unsupervised retrieval method, which improves both generation and retrieval more straightforwardly. Experimental results reveal that ChatKBQA achieves new state-of-the-art performance on standard KBQA datasets, WebQSP, and ComplexWebQuestions (CWQ). This work also provides a new paradigm for combining LLMs with knowledge graphs (KGs) for interpretable and knowledge-required question answering. Our code is publicly available.Comment: Preprin

Text2NKG: Fine-Grained N-ary Relation Extraction for N-ary relational Knowledge Graph Construction

Beyond traditional binary relational facts, n-ary relational knowledge graphs (NKGs) are comprised of n-ary relational facts containing more than two entities, which are closer to real-world facts with broader applications. However, the construction of NKGs still significantly relies on manual labor, and n-ary relation extraction still remains at a course-grained level, which is always in a single schema and fixed arity of entities. To address these restrictions, we propose Text2NKG, a novel fine-grained n-ary relation extraction framework for n-ary relational knowledge graph construction. We introduce a span-tuple classification approach with hetero-ordered merging to accomplish fine-grained n-ary relation extraction in different arity. Furthermore, Text2NKG supports four typical NKG schemas: hyper-relational schema, event-based schema, role-based schema, and hypergraph-based schema, with high flexibility and practicality. Experimental results demonstrate that Text2NKG outperforms the previous state-of-the-art model by nearly 20\% points in the $F_1$ scores on the fine-grained n-ary relation extraction benchmark in the hyper-relational schema. Our code and datasets are publicly available.Comment: Preprin

Study on fluorescence characteristics of the Ho 3+ :ZBLAN fiber under ~640 nm excitation

Abstract(#br)We investigated the absorption and emission characteristics of the Ho 3+ :ZBLAN fiber under ~640 nm excitation. Based on the Judd-Ofelt theory, a detailed spectroscopic analysis on excited states 5 I 6 and 5 I 7 of the Ho 3+ -ion was performed. The population dynamics was conducted by using the rate equation method, and a set of analytical expressions for population densities of various levels were obtained at steady state. Moreover, the fluorescence intensities of the 5 S 2 , 5 F 4 → 5 I 7 , 5 I 8 and 5 I 6 → 5 I 7 , 5 I 8 and 5 I 7 → 5 I 8 transitions were measured in different pumping powers. The simulated and experimental results are quite consistent. This work could provide the spectral information for optimal design of the visible oscillations in the Ho 3+ :ZBLAN fiber excited at ~640 nm

MicroRNAs in spermatogenesis dysfunction and male infertility: clinical phenotypes, mechanisms and potential diagnostic biomarkers

Infertility affects approximately 10–15% of couples worldwide who are attempting to conceive, with male infertility accounting for 50% of infertility cases. Male infertility is related to various factors such as hormone imbalance, urogenital diseases, environmental factors, and genetic factors. Owing to its relationship with genetic factors, male infertility cannot be diagnosed through routine examination in most cases, and is clinically called ‘idiopathic male infertility.’ Recent studies have provided evidence that microRNAs (miRNAs) are expressed in a cell-or stage-specific manner during spermatogenesis. This review focuses on the role of miRNAs in male infertility and spermatogenesis. Data were collected from published studies that investigated the effects of miRNAs on spermatogenesis, sperm quality and quantity, fertilization, embryo development, and assisted reproductive technology (ART) outcomes. Based on the findings of these studies, we summarize the targets of miRNAs and the resulting functional effects that occur due to changes in miRNA expression at various stages of spermatogenesis, including undifferentiated and differentiating spermatogonia, spermatocytes, spermatids, and Sertoli cells (SCs). In addition, we discuss potential markers for diagnosing male infertility and predicting the varicocele grade, surgical outcomes, ART outcomes, and sperm retrieval rates in patients with non-obstructive azoospermia (NOA)

The Apostasia genome and the evolution of orchids

Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth(1-3). Here we report the draft genome sequence of Apostasia shenzhenica(4), a representative of one of two genera that form a sister lineage to the rest of the Orchidaceae, providing a reference for inferring the genome content and structure of the most recent common ancestor of all extant orchids and improving our understanding of their origins and evolution. In addition, we present transcriptome data for representatives of Vanilloideae, Cypripedioideae and Orchidoideae, and novel third-generation genome data for two species of Epidendroideae, covering all five orchid subfamilies. A. shenzhenica shows clear evidence of a whole-genome duplication, which is shared by all orchids and occurred shortly before their divergence. Comparisons between A. shenzhenica and other orchids and angiosperms also permitted the reconstruction of an ancestral orchid gene toolkit. We identify new gene families, gene family expansions and contractions, and changes within MADS-box gene classes, which control a diverse suite of developmental processes, during orchid evolution. This study sheds new light on the genetic mechanisms underpinning key orchid innovations, including the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism; reveals relationships between the Orchidaceae subfamilies; and helps clarify the evolutionary history of orchids within the angiosperms

Solutions with concentration and cavitation to the Riemann problem for the isentropic relativistic Euler system for the extended Chaplygin gas

The solutions to the Riemann problem for the isentropic relativistic Euler system for the extended Chaplygin gas are constructed for all kinds of situations by using the method of phase plane analysis. The asymptotic limits of solutions to the Riemann problem for the relativistic extended Chaplygin Euler system are investigated in detail when the pressure given by the equation of state of extended Chaplygin gas becomes that of the pressureless gas. During the process of vanishing pressure, the phenomenon of concentration can be identified and analyzed when the two-shock Riemann solution tends to a delta shock wave solution as well as the phenomenon of cavitation also being captured and observed when the two-rarefaction-wave Riemann solution tends to a two-contact-discontinuity solution with a vacuum state between them

Trellis-Canonical Generator Matrices for Convolutional Codes

It was asserted in without proof, that a canonical generator matrix G(D) is trellis-canonical if and only if G(D) has the property that the span-length of the corresponding scalar matrix “G¯” cannot be reduced by a row operation of the form Row[m]= Row[n]D^s + Row[m], where s is an integer in the range 0⩽s⩽L and m ≠ n. In this paper, we prove a stronger result, viz., a basic PGM is trellis-canonical if and only if it is “row-reduced”. An efficient algorithm for converting a basic PGM into a trellis-canonical PGM is presented. We also correct an error in the general algorithm given in [3]