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7,086 results on '"Zhang, Zhijun"'

153. Corrigendum to “Non-inferiority of intermittent theta burst stimulation over the left V1 vs. classical target for depression: A randomized, double-blind trial”. [J. Affect. Disord. 343 (2023) 59–70]

Author

Kong, Yan, primary, Zhou, Jiawei, additional, Zhao, Mingge, additional, Zhang, Yuhua, additional, Tan, Tingting, additional, Xu, Zhi, additional, Hou, Zhenghua, additional, Yuan, Yonggui, additional, Tan, Liangliang, additional, Song, Ruize, additional, Shi, Yachen, additional, Feng, Haixia, additional, Wu, Wei, additional, Zhao, Yang, additional, and Zhang, Zhijun, additional

Published
2024
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167. Disturbed temporal dynamics of episodic retrieval activity with preserved spatial activity pattern in amnestic mild cognitive impairment: A simultaneous EEG-fMRI study

Author

Shu, Hao, Gu, Lihua, Yang, Ping, Lucas, Molly V, Gao, Lijuan, Zhang, Hongxing, Zhang, Haisan, Xu, Zhan, Wu, Wei, Li, Ling, and Zhang, Zhijun

Subjects
Biological Psychology, Psychology, Brain Disorders, Aging, Clinical Research, Alzheimer's Disease, Dementia, Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD), Neurodegenerative, Acquired Cognitive Impairment, Neurosciences, Aetiology, 2.1 Biological and endogenous factors, Mental health, Neurological, Brain, Cognitive Dysfunction, Electroencephalography, Humans, Magnetic Resonance Imaging, Memory, Episodic, Neuropsychological Tests, Amnestic mild cognitive impairment, Episodic memory, Familiarity, Recollection, Retrieval, Simultaneous EEG-fMRI, Biological psychology, Clinical and health psychology
Abstract

Episodic memory (EM) deficit is the core cognitive dysfunction of amnestic mild cognitive impairment (aMCI). However, the episodic retrieval pattern detected by functional MRI (fMRI) appears preserved in aMCI subjects. To address this discrepancy, simultaneous electroencephalography (EEG)-fMRI recording was employed to determine whether temporal dynamics of brain episodic retrieval activity were disturbed in patients with aMCI. Twenty-six aMCI and 29 healthy control (HC) subjects completed a word-list memory retrieval task during simultaneous EEG-fMRI. The retrieval success activation pattern was detected with fMRI analysis, and the familiarity- and recollection-related components of episodic retrieval activity were identified using event-related potential (ERP) analysis. The fMRI-constrained ERP analysis explored the temporal dynamics of brain activity in the retrieval success pattern, and the ERP-informed fMRI analysis detected fMRI correlates of the ERP components related to familiarity and recollection processes. The two groups exhibited similar retrieval success patterns in the bilateral posteromedial parietal cortex, the left inferior parietal lobule (IPL), and the left lateral prefrontal cortex (LPFC). The fMRI-constrained ERP analysis showed that the aMCI group did not exhibit old/new effects in the IPL and LPFC that were observed in the HC group. In addition, the aMCI group showed disturbed fMRI correlate of ERP recollection component that was associated with inferior EM performance. Therefore, in this study, we identified disturbed temporal dynamics in episodic retrieval activity with a preserved spatial activity pattern in aMCI. Taken together, the simultaneous EEG-fMRI technique demonstrated the potential to identify individuals with a high risk of cognitive deterioration.

Published
2021

172. A Gegenbauer Neural Network with Regularized Weights Direct Determination for Classification

Author

He, Jie, Chen, Tao, and Zhang, Zhijun

Subjects
Computer Science - Machine Learning, Statistics - Machine Learning
Abstract

Single-hidden layer feed forward neural networks (SLFNs) are widely used in pattern classification problems, but a huge bottleneck encountered is the slow speed and poor performance of the traditional iterative gradient-based learning algorithms. Although the famous extreme learning machine (ELM) has successfully addressed the problems of slow convergence, it still has computational robustness problems brought by input weights and biases randomly assigned. Thus, in order to overcome the aforementioned problems, in this paper, a novel type neural network based on Gegenbauer orthogonal polynomials, termed as GNN, is constructed and investigated. This model could overcome the computational robustness problems of ELM, while still has comparable structural simplicity and approximation capability. Based on this, we propose a regularized weights direct determination (R-WDD) based on equality-constrained optimization to determine the optimal output weights. The R-WDD tends to minimize the empirical risks and structural risks of the network, thus to lower the risk of over fitting and improve the generalization ability. This leads us to a the final GNN with R-WDD, which is a unified learning mechanism for binary and multi-class classification problems. Finally, as is verified in the various comparison experiments, GNN with R-WDD tends to have comparable (or even better) generalization performances, computational scalability and efficiency, and classification robustness, compared to least square support vector machine (LS-SVM), ELM with Gaussian kernel.

Published
2019

173. The Communication Complexity of Set Intersection and Multiple Equality Testing

Author

Huang, Dawei, Pettie, Seth, Zhang, Yixiang, and Zhang, Zhijun

Subjects
Computer Science - Information Theory, Computer Science - Computational Complexity
Abstract

In this paper we explore fundamental problems in randomized communication complexity such as computing Set Intersection on sets of size $k$ and Equality Testing between vectors of length $k$. Sa\u{g}lam and Tardos and Brody et al. showed that for these types of problems, one can achieve optimal communication volume of $O(k)$ bits, with a randomized protocol that takes $O(\log^* k)$ rounds. Aside from rounds and communication volume, there is a \emph{third} parameter of interest, namely the \emph{error probability} $p_{\mathrm{err}}$. It is straightforward to show that protocols for Set Intersection or Equality Testing need to send $\Omega(k + \log p_{\mathrm{err}}^{-1})$ bits. Is it possible to simultaneously achieve optimality in all three parameters, namely $O(k + \log p_{\mathrm{err}}^{-1})$ communication and $O(\log^* k)$ rounds? In this paper we prove that there is no universally optimal algorithm, and complement the existing round-communication tradeoffs with a new tradeoff between rounds, communication, and probability of error. In particular: 1. Any protocol for solving Multiple Equality Testing in $r$ rounds with failure probability $2^{-E}$ has communication volume $\Omega(Ek^{1/r})$. 2. There exists a protocol for solving Multiple Equality Testing in $r + \log^*(k/E)$ rounds with $O(k + rEk^{1/r})$ communication, thereby essentially matching our lower bound and that of Sa\u{g}lam and Tardos. Our original motivation for considering $p_{\mathrm{err}}$ as an independent parameter came from the problem of enumerating triangles in distributed ($\textsf{CONGEST}$) networks having maximum degree $\Delta$. We prove that this problem can be solved in $O(\Delta/\log n + \log\log \Delta)$ time with high probability $1-1/\operatorname{poly}(n)$., Comment: 44 pages

Published
2019
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181. STUDYONDEFORMATIONFORMANDENERGYABSORPTIONCHARACTERISTICS OF METAL THIN-WALLED SANDWICH STRUCTURE (MT)

Author

ZOU GuangPing, YAN AnShi, CHANG ZhongLiang, LI YinChen, WU SongYang, and ZHANG ZhiJun

Subjects
Thin walled sandwich structure, Polyurethane, Specific energy absorption, Crushing force, Finite element analysis, Mechanical engineering and machinery, TJ1-1570, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

A thin-walled sandwich structure filled with polyurethane is introduced. Based on the hyperelastic constitutive model of polyurethane, the energy absorption characteristics of the structure are studied and compared with single-layer and double-layer thin-walled steel circular tubes. Applying quasi-static load and dynamic load to the three structures, the deformation mode, energy absorption characteristic parameters, crushing force and stroke efficiency of the three structures are obtained. The results show that under quasi-static loading, the thin-walled circular tube filled with polyurethane produces axisymmetric deformation, and the average load and specific energy absorption are higher than the other two structures. Under dynamic loading, the stroke efficiency of thin-walled circular tube filled with polyurethane is small, but the average load and specific energy absorption are higher than the other two structures.

Published
2023
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182. Wear Prediction and Visual Decision Support of Drop Forged Rivetless Chain for Conveyors

Author

Liu Manxian, Xu Zijia, Shen Xujia, Li Xiaodong, Zhang Zhijun, and Yang Yi

Subjects
Drop forged rivetless chain, Visual decision support, Wear prediction, Gray model, Machine vision, Mechanical engineering and machinery, TJ1-1570
Abstract

In order to accurately detect, predict and maintain the wear condition of drop forged rivetless chain for conveyors, the methods of wear prediction and active maintenance are developed based on gray model and visual decision support. The wear data are acquired by wear detection device based on machine vision. The obtained data are cleaned by defining and analyzing key parameters of wear condition. A wear prediction model is built based on the gray model. A decision-making support model is constructed that can obtain the optimal plan of maintenance by comprehensively evaluating the wear condition with the forecast data, historical data, and operating condition data. The wear condition can be presented in a three-dimensional and dynamic manner to quickly and accurately locate the wear chain by a visual simulation method. The experiment results show that the wear life prediction model has high fitting accuracy, low false alarm rates, and low missed detection rates of wear early-warning, which can satisfy the requirements of wear life prediction. Through the proposed wear prediction model and visual decision support method, the maintenance efficiency is significantly improved, and the risk of forced shutdown of the production line is reduced.

Published
2023
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