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Search Results: 1 - 10 of 19127 matches for " Feifei Song "
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On the positive and negative inertia of weighted graphs
Shuchao Li,Feifei Song
Mathematics , 2013,
Abstract: The number of the positive, negative and zero eigenvalues in the spectrum of the (edge)-weighted graph $G$ are called positive inertia index, negative inertia index and nullity of the weighted graph $G$, and denoted by $i_+(G)$, $i_-(G)$, $i_0(G)$, respectively. In this paper, the positive and negative inertia index of weighted trees, weighted unicyclic graphs and weighted bicyclic graphs are discussed, the methods of calculating them are obtained.
The Preparation and Catalytic Performance of Nanoporous CuO/CeO2 Composites  [PDF]
Caihua Wei, Xiaolong Zhang, Feifei Lu, Yanyan Song, Zhanbo Sun
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.37021
Abstract:

Nanoporous CuO/CeO2 ribbons are successfully prepared through dealloying melt-spun Al80-xCu20Cex (x = 0.5, 1, 2, 3, at%) alloy in a 5 wt% NaOH aqueous solution, followed by calcining in air. The samples are characterized by XRD, SEM, EDS, HRTEM, Raman and gas chromatograph. For the dealloyed melt-spun Al80-xCu20Cex (x = 0.5, 1, 2, 3, at%) alloy, the XRD results indicate that Cu and Cu2O are formed, while CuO and CeO2 are formed coupled with calcinations. The SEM shows that the CuO/CeO2 ribbons with a homogeneous pore/grain structure are thermally stable up to 600because uniform CeO2 particles are dispersedly loaded on the fine CuO grains of the porous structure, which is validated by TEM again. Meanwhile, the Raman spectra show that the concentration of oxygen vacancies reach a maximum value when the calcining temperature at 600. In addition, the gas chromatograph results show that the dealloyed Al78Cu20Ce2 ribbons with calcined at 600have the best active catalysis for CO oxidation and the rates of CO conversation reaching at 50% and 100% are 150and 320, respectively, owing to the synergetic effects of the CuO and CeO2 species.

Breast Tissue 3D Segmentation and Visualization on MRI
Hong Song,Xiangfei Cui,Feifei Sun
International Journal of Biomedical Imaging , 2013, DOI: 10.1155/2013/859746
Abstract: Tissue segmentation and visualization are useful for breast lesion detection and quantitative analysis. In this paper, a 3D segmentation algorithm based on Kernel-based Fuzzy C-Means (KFCM) is proposed to separate the breast MR images into different tissues. Then, an improved volume rendering algorithm based on a new transfer function model is applied to implement 3D breast visualization. Experimental results have been shown visually and have achieved reasonable consistency. 1. Introduction Recently, magnetic resonance imaging (MRI) technique has been widely used in diagnosing and detecting diseases. It provides an effective mean of noninvasively mapping the anatomy of a subject. It works better than X-ray computed tomography (CT) at soft tissue, such as breast. The three-dimensional segmentation and visualization of breast are useful for breast lesion detection and quantitative analysis. Segmentation is applied to extract the interesting tissues in the breast. Several algorithms have been developed for segmenting the breast tissues. Threshold-based method, the gradient method, polynomial approximation method, the active contour models, and classifier segmentation are used in breast skin segmentation. Raba et al. [1] summarized that threshold-based method, the gradient method, polynomial approximation method, the active contour models, and classifier segmentation are the main methods commonly used in breast skin segmentation. Chen et al. [2] introduced the fuzzy clustering algorithm to the tumor region segmentation which had achieved better results. Kannan et al. [3] made the breast region segmentation by introducing new objective function of fuzzy c-means with the help of hypertangent function, Lagrangian multipliers method, and kernel functions. However, these studies did not separate the fat and fibroglandular tissues. Pathmanathan [4] suggested a region-growing method, which required the user to manually choose one or more seed points. This method got satisfying results, but it is inefficient and time consuming. Nie [5] used two steps to segment the breast: firstly, locating the skin border and lungs region by standard FCM algorithm and secondly, extracting the fibroglandular tissue by an adaptive FCM algorithm. However, it is a semiautomated method. Two kinds of methods are mainly applied in volume visualization, which are surface rendering and volume rendering. For surface rendering, Marching Cubes (MC) algorithm [6] is usually used which was developed by Lorensen and Cline in 1987. MC represents 3D objects by surface representations such as
The extremal problems on the inertia of weighted bicyclic graphs
Shibing Deng,Shuchao Li,Feifei Song
Mathematics , 2013,
Abstract: Let $G_w$ be a weighted graph. The number of the positive, negative and zero eigenvalues in the spectrum of $G_w$ are called positive inertia index, negative inertia index and nullity of $G_w$, and denoted by $i_{+}(G_w)$, $i_{-}(G_w)$, $i_{0}(G_w)$, respectively. In this paper, sharp lower bound on the positive (resp. negative) inertia index of weighted bicyclic graphs of order $n$ with pendant vertices is obtained. Moreover, all the weighted bicyclic graphs of order $n$ with at most two positive, two negative and at least $n-4$ zero eigenvalues are identified, respectively.
Government R & D Subsidies, Political Relations and Technological SMEs Innovation Transformation  [PDF]
Feifei Yu
iBusiness (IB) , 2013, DOI: 10.4236/ib.2013.53B022
Abstract:

This paper studies the effect of government research and development (R&D) subsidies and political relations on the innovative activities of technological small and medium-sized enterprises (SMEs). Moreover, the technology innovation path of SMEs is an important issue related to government R&D subsidies. This paper explores these effects using multiple case studies. Through case analyses of four biological pharmaceutical enterprises, we found that first, technological SMEs that receive a significant amount of government R&D subsidies will transform from exploitative innovation to explorative innovation in a short amount of time, whereas technological SMEs that receive less government R&D subsidies will perform less innovative activities over a long time. Second, technological SMEs with strong political relations tend to do more explorative innovation, whereas technological SMEs with weak political relations tend to do more exploitative innovation. Third, technological SMEs with strong political relations will promote the positive effect of government R&D subsidies on their innovation performance.

The Retailers’ Choices of Profit Strategies in a Cournot Duopoly: Relative Profit and Pure Profit  [PDF]
Feifei Zheng
Modern Economy (ME) , 2017, DOI: 10.4236/me.2017.82014
Abstract: To investigate the influence of the relative performance on retailers’ choices of profit strategies, a Cournot competition model composed of two private retailers is proposed, in which retailers are facing the problem of choosing a strategy from pure profit and relative profit. The study shows that, 1) when its competitor pursues relative profit, the retailer will adopt pure profit strategy if the degree of relative performance of its competitor is high enough. Otherwise, the retailer will adopt the relative profit strategy. 2) The more relative profit-maximizing retailers there are, the more intense market competition will be, the lower market price will decrease. 3)?Under a certain degree of relative performance, the strategy profiles (relative profit, relative profit), (relative profit, pure profit) and (pure profit, relative profit) are all likely to be Nash equilibrium, except the strategy profile (pure profit, pure profit).
A Novel Newborn Rat Kernicterus Model Created by Injecting a Bilirubin Solution into the Cisterna Magna
Sijie Song, Ying Hu, Xianfang Gu, Feifei Si, Ziyu Hua
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0096171
Abstract: Background Kernicterus still occurs around the world; however, the mechanism of bilirubin neurotoxicity remains unclear, and effective treatment strategies are lacking. To solve these problems, several kernicterus (or acute bilirubin encephalopathy) animal models have been established, but these models are difficult and expensive. Therefore, the present study was performed to establish a novel kernicterus model that is simple and affordable by injecting unconjugated bilirubin solution into the cisterna magna (CM) of ordinary newborn Sprague-Dawley (SD) rats. Methods On postnatal day 5, SD rat pups were randomly divided into bilirubin and control groups. Then, either bilirubin solution or ddH2O (pH = 8.5) was injected into the CM at 10 μg/g (bodyweight). For model characterization, neurobehavioral outcomes were observed, mortality was calculated, and bodyweight was recorded after bilirubin injection and weaning. Apoptosis in the hippocampus was detected by H&E staining, TUNEL, flow cytometry and Western blotting. When the rats were 28 days old, learning and memory ability were evaluated using the Morris water maze test. Results The bilirubin-treated rats showed apparently abnormal neurological manifestations, such as clenched fists, opisthotonos and torsion spasms. Bodyweight gain in the bilirubin-treated rats was significantly lower than that in the controls (P<0.001). The early and late mortality of the bilirubin-treated rats were both dramatically higher than those of the controls (P = 0.004 and 0.017, respectively). Apoptosis and necrosis in the hippocampal nerve cells in the bilirubin-treated rats were observed. The bilirubin-treated rats performed worse than the controls on the Morris water maze test. Conclusion By injecting bilirubin into the CM, we successfully created a new kernicterus model using ordinary SD rats; the model mimics both the acute clinical manifestations and the chronic sequelae. In particular, CM injection is easy to perform; thus, more stable models for follow-up study are available.
Research on the fast Fourier transform of image based on GPU
Feifei Shen,Zhenjian Song,Congrui Wu,Jiaqi Geng,Qingyun Wang
Computer Science , 2015,
Abstract: Study of general purpose computation by GPU (Graphics Processing Unit) can improve the image processing capability of micro-computer system. This paper studies the parallelism of the different stages of decimation in time radix 2 FFT algorithm, designs the butterfly and scramble kernels and implements 2D FFT on GPU. The experiment result demonstrates the validity and advantage over general CPU, especially in the condition of large input size. The approach can also be generalized to other transforms alike.
The Effect of Job Autonomy on Psychological Well-Being: The Mediating Role of Personal Initiative  [PDF]
Feifei Yang, Yue Zhao
Open Journal of Social Sciences (JSS) , 2018, DOI: 10.4236/jss.2018.611017
Abstract: Employees’ psychological well-being is an important factor affecting organizational performance. Thus, through empirical study, the present article investigates the influence of employees’ job autonomy on their psychological well-being. Specifically, personal initiative will mediate this relationship. To examine a series of hypotheses we developed, online survey was used to collect data. Finally, 380 respondents were accepted. Empirical data showed that employees’ job autonomy is positively related to psychological well-being. Namely, the psychological well-being of employees will gain dramatic improvement when they possess high job autonomy. In addition, through the way of path analysis, we revealed that personal initiative plays a role of intermediary mechanism in the relationship between job autonomy and psychological well-being. In last part, we discussed the contribution, limitations, and the directions of future research.
Influence of Haze-Fog on Consumers’ Desire for Money  [PDF]
Liangmu Wu, Feifei Yang
Open Journal of Social Sciences (JSS) , 2019, DOI: 10.4236/jss.2019.71017
Abstract: With the increase of haze-fog, it seriously affects the people’s quality of life. Most studies link haze-fog to diseases, environmental issues or governance and policy. However, the relationship between haze-fog and psychology and behavior remains relatively underexplored in the psychology literature. Drawing from regulatory focus theory, this paper explores how haze-fog influences individuals’ psychological states and behavior. Specifically, we design an experiment to examine how haze-fog influences consumers’ desire for money. Results indicate that haze-fog is negatively related to consumers’ desire for money (Msunny day = 3.79, Mmoderate pollution = 3.99, Msevere pollution = 5.49, F(2,105) = 10.67, p < 0.01), and the perception of defensive psychology mediates the relationship between haze-fog and consumers’ desire for money (95% CI [0.0102, 0.7597]). This paper shows that haze-fog does not only influence our life, but also our purchasing intentions. It reveals that when haze-fog is severe, it evokes consumers’ defensive psychology, and then it decreases consumers’ desire for money. Future research can focus on the other haze-fog related consumer psychology and explore haze-fog related marketing.
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