2,683 research outputs found

    A Recognition Approach Study on Chinese Field Term Based Mutual Information /Conditional Random Fields

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    AbstractA new auto-recognition approach based on mutual information/ Conditional Random Fields (CRFs) was put forward in this study. Firstly, statistics-based mutual information algorithm was applied to separate the Chinese words accurately, then the sub-words were picked out from the accurate separation according to the entropy of the left and right information. Secondly, the relative frequency of the sub-words was calculated. Thirdly, three training characteristics, including words, part of speech and relative frequency, were used as training datasets to obtain a model for field terms characters by CRFs. Thirdly, the Chinese words recognition was accomplished by the CRFs model. Finally, a practical experiment was executed and the results showed that the precision, percentage and Fmeasure of the recognition is 78.63%, 87.10% and 82.65% respectively, which is significant better the normal mutual information/ Conditional Random Fields (CRFs) algorithm

    Theoretical Analysis on Deflagration-to-Detonation Transition

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    The study on deflagration-to-detonation transition (DDT) is very important because this mechanism has relevance to safety issues in industries, where combustible premixed gases are in general use. However, the quantitative prediction of DDT is one of the major unsolved problems in combustion and detonation theory to date. In this paper, the DDT process is studied theoretically and the critical condition is given by a concise theoretical expression. The results show that a deflagration wave propagating with about 60% Chapman-Jouguet (C-J) detonation velocity is a critical condition. This velocity is the maximum propagating velocity of a deflagration wave and almost equal to the sound speed of combustion products. When this critical conation is reached, a C-J detonation is triggered immediately. This is the quantitative criteria of the DDT process

    Application of Virtual Simulation Technology in Theory and Experiment Teaching of Air Pollution Control Engineering

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    Virtual reality technology provides great convenience for humans to explore the macro and micro worlds due to its extremely realistic experience, and it will be seen in all walks of life in the future. This paper focuses on the analysis of the current situation of virtual simulation technology in the teaching application of air pollution control engineering theory teaching and experimental teaching, as well as the advantages and disadvantages of application. Furthermore, the development and prospect of virtual simulation technology in air pollution control engineering theory and experimental teaching are summarized. Keywords: virtual simulation technology, air pollution control engineering, theoretical teaching, experimental teaching DOI: 10.7176/JEP/13-29-08 Publication date:October 31st 202

    Domain-Generalized Face Anti-Spoofing with Unknown Attacks

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    Although face anti-spoofing (FAS) methods have achieved remarkable performance on specific domains or attack types, few studies have focused on the simultaneous presence of domain changes and unknown attacks, which is closer to real application scenarios. To handle domain-generalized unknown attacks, we introduce a new method, DGUA-FAS, which consists of a Transformer-based feature extractor and a synthetic unknown attack sample generator (SUASG). The SUASG network simulates unknown attack samples to assist the training of the feature extractor. Experimental results show that our method achieves superior performance on domain generalization FAS with known or unknown attacks.Comment: IEEE International Conference on Image Processing (ICIP 2023

    Cold hardiness of Phauda flammans (Lepidoptera: Zygaenidae) larvae

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    This study aimed to determine the cold hardiness of Phauda flammans (Lepidoptera: Zygaenidae) larvae. Supercooling points of the 1st–6th instar larvae of P. flammans ranged from –7.7 to –13.0 °C. The lethal temperatures were –8 °C for 1st, –5 °C for 2nd, and –7 °C for 3rd–6th instars. Lethal times at the instar-specific lethal temperatures were 12 h for 1st, 14 h for 2nd, 15 h for 3rd, 17 h for 4th, and 18 h for 5th–6th instars. The times required for all larvae to die in an incubator at 5 °C were 30 d for 1st, 3rd, 4th, and 5th instars, and 25 d for 2nd and 6th instars. The findings suggest that P. flammans is a chill-intolerant species, and larvae will die if the air temperature decreases to –5 to –8 °C for 12–18 h or to 5 °C for 25–30 d. Such conditions are, however, unlikely to occur in southern China
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