Fast and Accurate Neural Word Segmentation for Chinese

Neural models with minimal feature engineering have achieved competitive performance against traditional methods for the task of Chinese word segmentation. However, both training and working procedures of the current neural models are computationally inefficient. This paper presents a greedy neural word segmenter with balanced word and character embedding inputs to alleviate the existing drawbacks. Our segmenter is truly end-to-end, capable of performing segmentation much faster and even more accurate than state-of-the-art neural models on Chinese benchmark datasets.Comment: To appear in ACL201

Spectral analysis for preconditioning of multi-dimensional Riesz fractional diffusion equations

In this paper, we analyze the spectra of the preconditioned matrices arising from discretized multi-dimensional Riesz spatial fractional diffusion equations. The finite difference method is employed to approximate the multi-dimensional Riesz fractional derivatives, which will generate symmetric positive definite ill-conditioned multi-level Toeplitz matrices. The preconditioned conjugate gradient method with a preconditioner based on the sine transform is employed to solve the resulting linear system. Theoretically, we prove that the spectra of the preconditioned matrices are uniformly bounded in the open interval (1/2,3/2) and thus the preconditioned conjugate gradient method converges linearly. The proposed method can be extended to multi-level Toeplitz matrices generated by functions with zeros of fractional order. Our theoretical results fill in a vacancy in the literature. Numerical examples are presented to demonstrate our new theoretical results in the literature and show the convergence performance of the proposed preconditioner that is better than other existing preconditioners

Research on the Application of PBL Teaching Method in Physics Experiment Teaching

Discuss the method and effect of problem-based teaching method PBL in the teaching of physics experiment in junior high school Method A total of 92 students in two junior high school classes were selected and one of them was randomly set as the experimental group 46 students and the other one was the control group 456 students The experimental group added PBL teaching on the basis of traditional teaching methods Methods the control group was taught according to the traditional teaching method only and finally the teaching effect of the two groups was compared Results The physics performance of the experimental group was significantly higher than that of the traditional teaching group P 0 05 The students in the experimental group were better than traditional teaching in subjective evaluations such as learning initiative learning interest thinking ability training practical ability and innovation ability Conclusion The PBL teaching model is more adapted to the development of the times and the effect is better than traditional teaching It can combine the learning and practical skills of students and the comprehensive ability can be greatly improve

Covert Laparoscopic Cholecystectomy: A New Minimally Invasive Technique

To further improve our developed transumbilical endoscopic surgery (TUES), we developed a completely covert laparoscopic cholecystectomy (LC). Twelve cases of LC were recruited for this new approach. First, a 10-mm trocar was placed above the umbilicus for inserting the laparoscope. Two 5-mm trocars were then placed near the right and left ends of the superior margin of the suprapubic hair. After the 5-mm 30° laparoscope was shifted to the left suprapubic trocar, the harmonic scalper, electric hook, and grasper were inserted either through the 10-mm umbilical trocar or through the right suprapubic trocar. All gallbladders were successfully removed without intraoperative complications. The mean operating time was 28.5±5.7min (range 20-45min). All patients felt well after surgery and did not need postoperative analgesia. They resumed free oral intake 6h after the procedure. All patients were satisfied with the appearance of the incisions, which were completely hidden in the umbilicus and suprapubic hair. The approach we developed has overcome both external instrument interference around the umbilicus and the loss of triangulation in the operative field. It is relatively simpler than a typical TUES and offers better cosmetic results

Retinal nerve fiber layer thickness measured by optical coherence tomography in Chinese teenagers aged from 13 years old to 18 years old

AIM: To establish a reference range of retinal nerve fiber layer(RNFL)thickness by optical coherence tomography(OCT)in Chinese teenagers aged from 13 to 18 years old, and investigate its relationship with age, eye side, gender, and ethnic group.<p>METHODS: A total of 402 eyes from 201 normal Chinese aged from 13 to 18 years old were recruited for this study. Optic disk with 3.4mm diameter circle in different global average, quadrant and part-time bit retinal nerve fiber layer thickness(RNFLT)was measured by RNFL thickness average analysis program. Their RNFLT at different part-time bit, quadrant and global average RNFLT around the disc were measured by OCT with 3.4mm diameter circle, using the RNFL thickness average analysis program. The data was analyzed with SPSS statistical 19.0. The influences of several factors(such as age, eye side, gender, and ethnic group)on RNFLT were also analyzed.<p>RESULTS: The global average RNFLT at 13, 14, 15, 16, 17, 18 years old was 108.32±9.42μm, 109.23±9.67μm, 110.36±11.14μm, 111.27±10.21μm, 109.23±9.67μm, 112.11±8.83μm respectively. RNFLT of right eyes was 109.82±8.93μm and of left eyes was 110.33±9.89μm. All of the male's average RNFLT was 110.14±10.02μm, and all of the female's average RNFLT was 109.96±11.22μm. The average RNFLT of Han nationality was 110.22±9.31μm and of non-Han nationality was 109.87±8.65μm. The average RNFLT of all was 110.02±9.87μm, the RNFLT at the superior, nasal, inferior and temporal quadrant was 146.56 ±18.88μm, 76.49±13.28μm, 136.64±16.29μm, 82.01±12.55μm respectively. There was no significant difference in gender, eye side, and ethnic group(all <i>P</i><0.05), but the difference was significant compared with adult's data of the database. <p>CONCLUSION: This study has established a normal standard reference of RNFLT and its related indexes by OCT in Chinese teenagers aged 13-18 years old. Gender, age, eye side, and ethnic group have no effect on their RNFLT, which has significant difference with adult's data. And for the diagnosis and follow-up of diseases involving in RNFL changes, the adult's data can not be used

A Trace-restricted Kronecker-Factored Approximation to Natural Gradient

Second-order optimization methods have the ability to accelerate convergence by modifying the gradient through the curvature matrix. There have been many attempts to use second-order optimization methods for training deep neural networks. Inspired by diagonal approximations and factored approximations such as Kronecker-Factored Approximate Curvature (KFAC), we propose a new approximation to the Fisher information matrix (FIM) called Trace-restricted Kronecker-factored Approximate Curvature (TKFAC) in this work, which can hold the certain trace relationship between the exact and the approximate FIM. In TKFAC, we decompose each block of the approximate FIM as a Kronecker product of two smaller matrices and scaled by a coefficient related to trace. We theoretically analyze TKFAC's approximation error and give an upper bound of it. We also propose a new damping technique for TKFAC on convolutional neural networks to maintain the superiority of second-order optimization methods during training. Experiments show that our method has better performance compared with several state-of-the-art algorithms on some deep network architectures

Seneca Valley virus 3Cpro antagonizes host innate immune responses and programmed cell death

Seneca Valley virus (SVV), a member of the Picornaviridae family, may cause serious water blister diseases in pregnant sows and acute death in newborn piglets, which have resulted in economic losses in pig production. The 3C protease is a vital enzyme for SVV maturation and is capable of regulating protein cleavage and RNA replication of the virus. Additionally, this protease can impede the host’s innate immune response by targeting the interferon pathway’s principal factor and enhance virus replication by modulating the host’s RNA metabolism while simultaneously triggering programmed cell death. This article reviews recent studies on SVV 3C functions, which include viral replication promotion, cell apoptosis modulation and host immune response evasion, and provides a theoretical basis for research on preventing and controlling SVV infection