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Beijing, China

Zeng W.,Huazhong University of Science and Technology | Zou S.,Tinghua University | Zuo H.,Beijing Institute of Technology
Lecture Notes in Electrical Engineering

Functional magnetic resonance imaging (FMRI) has been widely used in the field of medicine and physiology, which realizes neuro imaging without damage. FMRI was initially applied to the analysis of FMRI images; however, its statistical analysis was limited to the elementary processes because of the complexities of the FMRI images and the difficulties to establish the neuromotor time–space model. In this chapter, we focus on the analysis of FMRI images based on large data. Firstly, we make the time-correlation analysis of the data to reduce the size of the data. Then, we further investigate the spatial characteristics of valid signals, and compare the predicted signal and the original signal in the time domain and frequency domain. We find that there is a strong relevance of FMRI data in both time and space area, which indicates that the stimulation signal of the brain radiates to the surroundings of the stimulated point, and the signal is continuous in time, not an impulse. © Springer International Publishing Switzerland 2015. Source

Xu W.,Ryerson University | Liu L.,University of Waterloo | Liu L.,Tinghua University | Zhou Y.,University of Waterloo | And 2 more authors.
Materials Science and Engineering A

The microstructures, tensile and fatigue properties of weld-bonded (WB) AZ31B-H24 Mg/Mg joints with different sizes of bonding area were evaluated and compared with the adhesive-bonded (AB) Mg/Mg joints. Typical equiaxed dendritic structures containing divorced eutectic Mg17Al12 particles formed in the fusion zone of both WB-1 (with a bonding area of 35mm×35mm) and WB-0.5 (with a bonding area of 17.5mm×35mm) joints. Less solidification shrinkage cracking was observed in the WB-0.5 joints than WB-1 joints. While the WB-0.5 joints exhibited a slightly lower maximum tensile shear stress than the AB-0.5 joints (with a bonding area of 17.5mm×35mm), the energy absorption was equivalent. Although the AB-0.5 joints exhibited a higher fatigue resistance at higher cyclic stress levels, both the AB-0.5 and WB-0.5 joints showed an equivalent fatigue resistance at lower cyclic stress levels. A higher fatigue limit was observed in the WB-0.5 joints than in the WB-1 joints owing to the presence of fewer shrinkage pores. Cohesive failure mode along the adhesive layer in conjunction with partial nugget pull-out from the weld was observed at the higher cyclic loads, and fatigue failure occurred in the base metal at the lower cyclic loads. © 2012 Elsevier B.V. Source

Guo Y.-N.,China University of Mining and Technology | Zhang S.,China University of Mining and Technology | Cheng J.,China University of Mining and Technology | Cheng J.,Tinghua University | Lin Y.,China University of Mining and Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

In cooperative interactive genetic algorithms, each user evaluates all individuals in every generation through human-machine interface, which makes users tired. So population size and generation are limited. That means nobody can evaluate all individuals in search space, which leads to the deviation between the users' best-liked individual and the optimal one by the evolution. In order to speed up the convergence, implicit knowledge denoting users' preference is extracted and utilized to induce the evolution. In the paper, users having similar preference are further divided into a group by K-means clustering method so as to share knowledge and exchange information each other. We call the group as knowledge alliance. The users included in a knowledge alliance vary dynamically while their preferences are changed. Taken a fashion evolutionary design system as example, simulation results show that the algorithm speeds up the convergence and decreases the number of individuals evaluated by users. This can effectively alleviate users' fatigue. © 2011 Springer-Verlag. Source

Lin W.,Peking Union Medical College | Jin L.,Tinghua University | Chen H.,Peking Union Medical College | Wu Q.,Peking Union Medical College | And 9 more authors.
Arthritis Research and Therapy

Introduction: IgG4-related disease (IgG4-RD) is a multisystem-involved autoimmune disease. Abnormally activated and differentiated B cells may play important roles. Regulatory B cells (Breg) are newly defined B cell subgroups with immunosuppressive functions. In this study, we investigated the differences of B cell subsets, the expressions of co-stimulatory molecules on B cells, and the function of Breg cells in patients with IgG4-RD, primary Sjögren's syndrome (pSS) as well as in healthy controls (HC).Methods: Newly diagnosed IgG4-RD patients (n = 48) were enrolled, 38 untreated pSS patients and 30 healthy volunteers were recruited as disease and healthy controls. To analyze B cell subsets and B cell activity, PBMCs were surface stained and detected by flow cytometry. The function of Breg cells was tested by coculturing isolated CD19 + CD24hiCD38hi Breg cells with purified CD4 + CD25- T cells. Serum cytokines were measured by ELISA and cytometric bead array. Relationship between clinical data and laboratory findings were analyzed as well.Results: Compared with pSS patients and HC, IgG4-RD patients had a lower frequency of peripheral Breg cells. Interestingly, CD19 + CD24-CD38hi B cell subsets were significantly higher in peripheral B cells from IgG4-RD patients than in pSS patients and HC, which correlated with serum IgG4 levels. The expression of BAFF-R and CD40 on B cells was significantly lower in IgG4-RD patients compared with those in pSS patients and HC. Unlike HC, Breg cells from pSS patients lacked suppressive functions.Conclusions: B cells in patients with IgG4-RD and pSS display a variety of abnormalities, including disturbed B cell subpopulations, abnormal expression of key signaling molecules, co-stimulatory molecules, and inflammatory cytokines. In addition, a significantly increased B cell subset, CD19 + CD24-CD38hi B cells, may play an important role in the pathogenesis of IgG4-RD. © 2014 Lin et al.; licensee BioMed Central Ltd. Source

Li J.,Nuclear Power Institute of China | Song X.-M.,Nuclear Power Institute of China | Lu J.-C.,Nuclear Power Institute of China | Li Z.-C.,Nuclear Power Institute of China | Li Z.-C.,Tinghua University
Hedongli Gongcheng/Nuclear Power Engineering

Numerical simulations were taken on single phase flow in a structured packed bed on different scaling using CFD modeling. The point contact between adjacent spheres was simplified with a new grid-generation method, and over 11 layers of spheres were calculated, 141 particles in all, which represents flow characteristics of a large scale packed bed in the real system. The scaling effect on the flow characteristics and pressure drop was investigated, and the resistance formulas on different scales were obtained. The mechanism of boundary effect on flow characteristics of a small channel was studied and the scope of the inlet/outlet effect on resistance characteristics is evaluated by the pressure drop on axial direction. Source

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