Contextual modeling of hand written Chinese character for recognition. II. Discriminative training

This is an extension of a companion paper entitled 'Contextual Modeling of Hand Written Chinese Character for Recognition (I) - A Comparative Study' which is also submitted to this conference for presentation. In this investigation, contextual models are discriminatively trained using a gradient projection technique. Both open test and close test recognition rates are substantially upgraded when compared with the results of the decision directed training algorithm reported in the other paper.published_or_final_versio

A study on the use of Gabor features for Chinese OCR

The authors revisit the topic of Gabor feature extraction for Chinese OCR. We adopt a very simple discriminant function to construct a maximum discriminant function based character recognizer. We experiment with a simple way of forming a feature vector for each character image by extracting Gabor features using one wavelength at locations uniformly sampled with one spatial resolution. Extensive experiments on large vocabulary Chinese OCR for both machine-printed and handwritten characters are performed by using a large amount of training and testing data to demonstrate the effectiveness of the Gabor features for Chinese OCR. Using Gabor features as raw features, we have constructed several state-of-the-art Chinese OCR engines.published_or_final_versio

A discrete contextual stochastic model for the off-line recognition of handwritten Chinese characters

We study a discrete contextual stochastic (CS) model for complex and variant patterns like handwritten Chinese characters. Three fundamental problems of using CS models for character recognition are discussed, and several practical techniques for solving these problems are investigated. A formulation for discriminative training of CS model parameters is also introduced and its practical usage investigated. To illustrate the characteristics of the various algorithms, comparative experiments are performed on a recognition task with a vocabulary consisting of 50 pairs of highly similar handwritten Chinese characters. The experimental results confirm the effectiveness of the discriminative training for improving recognition performance.published_or_final_versio

High Performance Chinese OCR Based on Gabor Features, Discriminative Feature Extraction and Model Training

We have developed a Chinese OCR engine for machine printed documents. Currently, our OCR engine can support a vocabulary of 6921 characters which include 6707 simplified Chinese characters in GB2312-80, 12 frequently used GBK Chinese characters, 62 alphanumeric characters, 140 punctuation marks and symbols. The supported font styles include Song, Fang Song, Kat, He, Yuan, LiShu, WeiBei, XingKai, etc. The averaged character recognition accuracy is above 99% for newspaper quality documents with a recognition speed of about 250 characters per second on a Pentium III-450 MHz PC yet only consuming less than 2 MB memory. We describe the key technologies we used to construct the above recognizer. Among them, we highlight three key techniques contributing to the high recognition accuracy, namely the use of Gabor features, the use of discriminative feature extraction, and the use of minimum classification error as a criterion for model training.published_or_final_versio

A piloted prevention program on drug abuse in adolescents in Hong Kong

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Graphene-based hybrid plasmonic waveguide for highly efficient broadband mid-infrared propagation and modulation

© 2018 Optical Society of America. In this paper, a graphene-based hybrid plasmonic waveguide is proposed for highly efficient broadband surface plasmon polariton (SPP) propagation and modulation at mid-infrared (mid-IR) spectrum. The hybrid plasmonic waveguide is composed of a monolayer graphene sheet in the center, a polysilicon gating layer, and two inner dielectric buffer layers and two outer parabolic-ridged silicon substrates symmetrically placed on both sides of the graphene. Owing to the unique parabolic-ridged waveguide structure, the light-graphene interaction and subwavelength SPPs confinement of the fundamental SPP mode for the hybrid waveguide can be significantly increased. Under the graphene chemical potential of 1.0 eV, the proposed waveguide can achieve outstanding SPP propagation performance with long propagation length of 12.1-16.7 μm and small normalized mode area of ~10−4 in the frequency range of 10-20 THz, exhibiting more than one order smaller in the normalized mode area while remaining the propagation length almost the same level with respect to the hybrid plasmonic waveguide without parabolic ridges. By tuning the graphene chemical potential from 0.1 to 1.0 eV, we demonstrate the waveguide has a modulation depth greater than 51% for the frequency ranging from 10 to 20 THz and reaches a maximum of nearly 100% at the frequency higher than 18 THz. Benefitting from the excellent broadband mid-IR propagation and modulation performance, the graphene-based hybrid plasmonic waveguide may open up a new way for various mid-IR waveguides, modulators, interconnects and optoelectronic devices

Corrigendum to "Assessment of China's virtual air pollution transport embodied in trade by using a consumption-based emission inventory" published in Atmos. Chem. Phys., 15, 5443-5456, 2015

No abstract available

Assessment of China's virtual air pollution transport embodied in trade by using a consumption-based emission inventory

Substantial anthropogenic emissions from China have resulted in serious air pollution, and this has generated considerable academic and public concern. The physical transport of air pollutants in the atmosphere has been extensively investigated; however, understanding the mechanisms how the pollutant was transferred through economic and trade activities remains a challenge. For the first time, we quantified and tracked China's air pollutant emission flows embodied in interprovincial trade, using a multiregional input - output model framework. Trade relative emissions for four key air pollutants (primary fine particle matter, sulfur dioxide, nitrogen oxides and non-methane volatile organic compounds) were assessed for 2007 in each Chinese province. We found that emissions were significantly redistributed among provinces owing to interprovincial trade. Large amounts of emissions were embodied in the imports of eastern regions from northern and central regions, and these were determined by differences in regional economic status and environmental policy. It is suggested that measures should be introduced to reduce air pollution by integrating cross-regional consumers and producers within national agreements to encourage efficiency improvement in the supply chain and optimize consumption structure internationally. The consumption-based air pollutant emission inventory developed in this work can be further used to attribute pollution to various economic activities and final demand types with the aid of air quality models

Antitumor effect of the ethanol extract of Scutellaria baicalensis on the mice bearing U14 cervical cancer

Scutellaria baicalensis which is a traditional plant amedica in China possesses a wide anti-cancer effect. However, the inhibition effect and mechanism of S. baicalensis on cervical cancer is not clear up to now. In our study, two kinds of ethanol extract of S. baicalensis were used in U14 cervical cancer mice. The rate of tumor inhibition was detected, and the tumor cell morphology was observed by hematoxylin and eosin (H.E.) staining method. The cell cycle and apoptosis rate were examined by flow cytometry and the content of tumor necrosis factor-alpha (TNF-α) in serum was determined by enzyme-linked immunosorbent assay (ELISA) kit. Furthermore, the expression of B-cell lymphoma 2 (Bcl-2) and Bax gene was detected by immunohistochemistry method. The results showed that the tumor growth could be inhibited with the highest inhibition rate of 59.86% and the apoptosis of tumor cells could be induced and cell cycles were arrested at S phase in the ethanol extract of S. baicalensis groups. Besides, the content of TNF-α in serum was significantly increased (P<0.05). The Bcl-2 positive cells got significance reduction and Bax positive cells were increased. So we conclude that the ethanol extract of S. baicalensis can inhibit the growth of tumor cells, arrest the cell cycle and induce the cells apoptosis and increase the content of tumor necrosis factor-alpha TNF-α in serum. The mechanism of anti-tumor activity might be associated with down regulating the level of Bcl-2 gene and up regulating the level of Bax gene.Key words: Scutellaria baicalensis, cervical cancer, cell cycle, cell apoptosis, TNF-α, Bcl-2, Bax