Improved Element-Free Galerkin method (IEFG) for solving three-dimensional elasticity problems

Zhang, Zan,Liew, K.M. Techno-Press 2010 Interaction and multiscale mechanics Vol.3 No.2

The essential idea of the element-free Galerkin method (EFG) is that moving least-squares (MLS) approximation are used for the trial and test functions with the variational principle (weak form). By using the weighted orthogonal basis function to construct the MLS interpolants, we derive the formulae for an improved element-free Galerkin (IEFG) method for solving three-dimensional problems in linear elasticity. There are fewer coefficients in improved moving least-squares (IMLS) approximation than in MLS approximation. Also fewer nodes are selected in the entire domain with the IEFG method than is the case with the conventional EFG method. In this paper, we selected a few example problems to demonstrate the applicability of the method.

New Evidence of Interest Rate Pass-through in Taiwan: A Nonlinear Autoregressive Distributed Lag Model

Zan Zhang,Su-Ling Tsai,Tsangyao Chang 연세대학교 동서문제연구원 2017 Global economic review Vol.46 No.2

We adopt the newly developed nonlinear autoregressive distributed lag model, advanced by Shin, Yu and Greenwood-Nimmo [(2014) Modelling asymmetric cointegration and dynamic multipliers in a nonlinear ARDL framework, in: Festschrift in Honor of Peter Schmidt, pp. 281–314 (New York: Springer)], to investigate the interest rate(IR) pass-through (IRPT) mechanism in Taiwan from 1971 M07 to 2014 M11. We find that the incomplete IRPT mechanism of deposit markets shows an asymmetric adjustment in the short run and symmetric adjustments in the long run. The deposit rate is rigid downward, which supports the customer reaction hypothesis. Moreover, we find that both the short-run and the long-run IRPT channels from the policy rate to the lending rate are also incomplete in the short run but not in the long run. The purpose of this paper is to provide accurate assessment criteria for the central bank to understand the nonlinear dynamics among the policy IR and the retail IR, thus leading to more efficient policy-making and forecasting for the Taiwanese government.

LAMP, PCR, and real-time PCR detection of Acetobacter aceti in yogurt

Wei Zhou,Yan Zhang,Shuang Wang,Yuehua Li,Jingjing Zhang,Cuixia Zhang,Zan Wang,Zhisheng Zhang 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.1

Acetic acid bacteria (AAB) can spoil food. Acetobacter aceti as a core subgroup of AAB is usually isolated from yogurt. A. aceti should be timely and effectively detected to prevent yogurt contamination. The present study focused on A. aceti to establish an assay that can be performed to detect AAB in yogurt. LAMP, PCR, and real-time PCR were applied and compared for detecting A. aceti from pure culture and artificially contaminated yogurt samples. In pure culture, LAMP showed the highest detection sensitivity with 10−1 CFU/mL. For yogurt samples, the sensitivity limit of LAMP was 102 CFU/mL, which was lower than that of real-time PCR (101 CFU/mL). The results indicated that these methods could be quickly and efficiently applied to detect A. aceti. As LAMP technology has low cost and high detection efficiency, it can potentially be applied for detecting A. aceti in production and quality control programs of yogurt.

Human Action Recognition Via Multi-modality Information

Zan Gao,Jian-ming Song,Hua Zhang,An-An Liu,Yan-bing Xue,Guang-ping Xu 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

In this paper, we propose pyramid appearance and global structure action descriptors on both RGB and depth motion history images and a model-free method for human action recognition. In proposed algorithm, we firstly construct motion history image for both RGB and depth channels, at the same time, depth information is employed to filter RGB information, after that, different action descriptors are extracted from depth and RGB MHIs to represent these actions, and then multimodality information collaborative representation and recognition model, in which multi-modality information are put into object function naturally, and information fusion and action recognition also be done together, is proposed to classify human actions. To demonstrate the superiority of the proposed method, we evaluate it on MSR Action3D and DHA datasets, the well-known dataset for human action recognition. Large scale experiment shows our descriptors are robust, stable and efficient, when comparing with the-state-of-the-art algorithms, the performances of our descriptors are better than that of them, further, the performance of combined descriptors is much better than just using sole descriptor. What is more, our proposed model outperforms the state-of-the-art methods on both MSR Action3D and DHA datasets.

Human Action Recognition Using Pyramid Histograms of Oriented Gradients and Collaborative Multi-task Learning

( Zan Gao ),( Hua Zhang ),( An-an Liu ),( Yan-bing Xue ),( Guang-ping Xu ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.2

In this paper, human action recognition using pyramid histograms of oriented gradients and collaborative multi-task learning is proposed. First, we accumulate global activities and construct motion history image (MHI) for both RGB and depth channels respectively to encode the dynamics of one action in different modalities, and then different action descriptors are extracted from depth and RGB MHI to represent global textual and structural characteristics of these actions. Specially, average value in hierarchical block, GIST and pyramid histograms of oriented gradients descriptors are employed to represent human motion. To demonstrate the superiority of the proposed method, we evaluate them by KNN, SVM with linear and RBF kernels, SRC and CRC models on DHA dataset, the well-known dataset for human action recognition. Large scale experimental results show our descriptors are robust, stable and efficient, and outperform the state-of-the-art methods. In addition, we investigate the performance of our descriptors further by combining these descriptors on DHA dataset, and observe that the performances of combined descriptors are much better than just using only sole descriptor. With multimodal features, we also propose a collaborative multi-task learning method for model learning and inference based on transfer learning theory. The main contributions lie in four aspects: 1) the proposed encoding the scheme can filter the stationary part of human body and reduce noise interference; 2) different kind of features and models are assessed, and the neighbor gradients information and pyramid layers are very helpful for representing these actions; 3) The proposed model can fuse the features from different modalities regardless of the sensor types, the ranges of the value, and the dimensions of different features; 4) The latent common knowledge among different modalities can be discovered by transfer learning to boost the performance.

FEM Simulation and Test Verification of PD Ultrasonic Signal Propagation in a Power Transformer Model

Zan Wang,Chaofei Gao,Liwei Zheng,Jikun Ren,Wei Wang,Yushuai Zhang,Shijie Han 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

Ultrasonic signals will be generated when partial discharge occurs in internal insulation faults in large oil immersed power transformers: because the ultrasonic signal has strong anti-interference ability and has no direct electromagnetic contact with the equipment, it is widely used in transformer fault detection and positioning. In this paper, the fi nite element method (FEM) is used to simulate the ultrasonic signal in a 35 kV power transformer. The infl uence of transformer case on ultrasonic signal propagation is considered, and the propagation law of the ultrasonic signal inside the transformer is obtained. Fabry–Pérot (F–P) fi bre acoustic sensors with a centre frequency of 28 kHz were fabricated. A partial discharge detection test was carried out in a 35 kV transformer winding model using the F–P sensors. The test results show that the ultrasonic waveform detected by the F–P sensors are in good agreement with the simulation results, and the propagation of the ultrasonic wave inside the transformer is verifi ed. It lays a foundation for detecting and locating PDs in power transformer by F–P acoustic sensors.

Lupus-prone MRL/faslpr/lpr mice display increased AID expression and extensive DNA lesions, comprising deletions and insertions, in the immunoglobulin locus: concurrent upregulation of somatic hypermutation and class switch DNA recombination.

Zan, Hong,Zhang, Jinsong,Ardeshna, Sona,Xu, Zhenming,Park, Seok-Rae,Casali, Paolo Harwood 2009 Autoimmunity Vol.42 No.2

<P>Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of an array of pathogenic autoantibodies, including high-affinity anti-dsDNA IgG antibodies. These autoantibodies are mutated and class-switched, mainly to IgG, indicating that immunoglobulin (Ig) gene somatic hypermutation (SHM) and class switch DNA recombination (CSR) are important in their generation. Lupus-prone MRL/fas(lpr/lpr) mice develop a systemic autoimmune syndrome that shares many features with human SLE. We found that Ig genes were heavily mutated in MRL/fas(lpr/lpr) mice and contained long stretches of DNA deletions and insertions. The spectrum of mutations in MRL/fas(lpr/lpr) B cells was significantly altered, including increased dG/dC transitions, increased targeting of the RGYW/WRCY mutational hotspot and the WGCW AID-targeting hotspot. We also showed that MRL/fas(lpr/lpr) greatly upregulated CSR, particularly to IgG2a and IgA in B cells of the spleen, lymph nodes and Peyer's patches. In MRL/fas(lpr/lpr) mice, the significant upregulation of SHM and CSR was associated with increased expression of activation-induced cytidine deaminase (AID), which mediates DNA lesion, the first step in SHM and CSR, and translesion DNA synthesis (TLS) polymerase (pol) theta, pol eta and pol zeta, which are involved in DNA synthesis/repair process associated with SHM and, possibly, CSR. Thus, in lupus-prone MRL/fas(lpr/lpr) mice, SHM and CSR are upregulated, as a result of enhanced AID expression and, therefore, DNA lesions, and dysregulated DNA repair factors, including TLS polymerases, which are involved in the repair process of AID-mediated DNA lesions.</P>

Human Action Recognition Via Multi-modality Information

Gao, Zan,Song, Jian-Ming,Zhang, Hua,Liu, An-An,Xue, Yan-Bing,Xu, Guang-Ping The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

In this paper, we propose pyramid appearance and global structure action descriptors on both RGB and depth motion history images and a model-free method for human action recognition. In proposed algorithm, we firstly construct motion history image for both RGB and depth channels, at the same time, depth information is employed to filter RGB information, after that, different action descriptors are extracted from depth and RGB MHIs to represent these actions, and then multimodality information collaborative representation and recognition model, in which multi-modality information are put into object function naturally, and information fusion and action recognition also be done together, is proposed to classify human actions. To demonstrate the superiority of the proposed method, we evaluate it on MSR Action3D and DHA datasets, the well-known dataset for human action recognition. Large scale experiment shows our descriptors are robust, stable and efficient, when comparing with the-state-of-the-art algorithms, the performances of our descriptors are better than that of them, further, the performance of combined descriptors is much better than just using sole descriptor. What is more, our proposed model outperforms the state-of-the-art methods on both MSR Action3D and DHA datasets.

Three homologous genes encoding functional D8-sphingolipid desaturase in Populus tomentosa

Shu-Fen Li,Zan-Min Hu,Guo-Jun Zhang,Ying-Chun Yuan,Cong-Hui Wang,Wu-Jun Gao,Chuan-Liang Deng,Long-Dou Lu 한국유전학회 2014 Genes & Genomics Vol.36 No.3

Δ8-sphingolipid desaturase is characterized by itsability to catalyze desaturation at the C8 position of the longchainbase of sphingolipids in plants. No previous studieshave been conducted on genes encoding Δ8-sphingolipiddesaturases in the woody plant Populus tomentosa. In thisstudy, three genes that encode Δ8-sphingolipid desaturasewere isolated fromP. tomentosa. Among these genes, PtD8Aand PtD8B showed high sequence similarity; whereas PtD8Cexhibited large sequence divergence.RT-PCRresults showedthat PtD8A and PtD8B were expressed in all tissues detected,whereas PtD8C was not expressed in roots. Heterologousexpression in yeast revealed that PtD8A/B/C were functionalΔ8-sphingolipid desaturases, and can catalyze the C18-phytosphingeninedesaturation to produce 8(Z)- and 8(E)-C18-phytosphingenine.However, the conversion rate and ratios ofthe two products differed. Compared with control cells,transgenic yeasts expressing PtD8A/B/C exhibited enhancedaluminum tolerance. Our findings further elucidated thebiochemical functions and evolutionary history ofΔ8-sphingolipid desaturases in plants. Candidate genes forbreeding new poplar germplasm resources with enhancedtolerance ability to aluminium were also provided.

Sensorless PMSM Control with Sliding Mode Observer Based on Sigmoid Function

Ren Ningning,Fan Le,Zhang Zan 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2

It is impossible to install or apply position sensors appropriately in some special applications of PMSM. Sensorless PMSM control is an appropriate choice to solve some problems in the control of PMSM. It is necessary to acquire an estimated position precisely and avoid the chattering phenomenon for sensorless PMSM control. This paper proposes an algorithm for estimating position with sliding mode observer (SMO) based on sigmoid function, and a suffi cient condition that leads SMO into a sliding surface is acquired using Lyapunov stabilization analysis. The outcome of this study shows that SMO based on sigmoid function for sensorless PMSM control can estimate position with high precision and avoid chattering phenomenon under the condition of diff erent velocity and load. However, the estimated position needs to be compensated for according to load, and the compensating value is in proportion to the value of the current.