一类时延脑电模型的分岔研究及其控制

基于Robinson等人对一类简约脑皮层电模型的研究,对该模型的分叉特性进行了研究.考虑到兴奋型神经元和抑制型神经元之间信息传递的延时,讨论了延时对简约模型稳定性的影响,并给出了模型发生Hopf分岔的条件.结果表明,当时延在一定的阈值内,模型可以保持其稳定状态.进一步地,针对该模型设计了导数反馈控制器,消除了Hopf分岔现象.数值仿真验证了理论的有效性.

脑皮层功能柱模型中的Hopf分岔

研究了一种脑皮层功能柱的集中参数模型,分析了平衡点的稳定性,并给出了其Hopf分岔条件.数值仿真显示,该模型在不同参数条件下可以表现为多种不同的脑电波信号.通过改变外部输入脉冲密度,模型状态响应经历了稳定平衡点和极限环的过程,验证了其Hopf分岔的存在条件.对Hopf分岔的研究为进一步深入了解大脑的非线性结构提供了理论依据.

脑电监测SD大鼠异氟醚全身麻醉模型的建立及脑电分析

目的:建立脑电监测SD大鼠异氟醚全身麻醉模型并分析脑电监测结果。方法:随机选取SD大鼠20只,先行脑电电极置入术,术后使用密闭吸入麻醉动物行为学观察圆筒,观察异氟醚引起的麻醉诱导、维持、觉醒状态并记录诱导、觉醒时间。将记录的行为学结果对照典型脑电图波形改变判断麻醉深度。结果:实验SD大鼠均检测出脑电图,通过对照行为学观察发现动态脑电监测结果同异氟醚麻醉过程进展一致。在麻醉过程中SD大鼠出现典型的全身麻醉脑电循环。结论:动态脑电监测和SD大鼠行为学观察可以准确反应全身麻醉深度。

Application of CEDA and ASPIC computer packages to the hairtail (Trichiurus japonicus) fishery in the East China Sea

Surplus-production models are widely used in fish stock assessment and fisheries management due to their simplicity and lower data demands than age-structured models such as Virtual Population Analysis. The CEDA (catch-effort data analysis) and ASPIC (a surplus-production model incorporating covariates) computer packages are data-fitting or parameter estimation tools that have been developed to analyze catch-and-effort data using non-equilibrium surplus production models. We applied CEDA and ASPIC to the hairtail (Trichiurus japonicus) fishery in the East China Sea. Both packages produced robust results and yielded similar estimates. In CEDA, the Schaefer surplus production model with log-normal error assumption produced results close to those of ASPIC. CEDA is sensitive to the choice of initial proportion, while ASPIC is not. However, CEDA produced higher R 2 values than ASPIC.

Evaluation of Normal Adrenal Gland Volume by 64-slice CT

Objective To measure volume and other parameters of normal adrenal glands in Chinese adults with 64-slice multidetector CT, to evaluate the relationship of volume result with age, sex and body size, and to explore the correlations between adrenal volume and other measurements. Methods This study was based on 125 acquired contrast-enhanced upper abdominal CT scans performed with a 64-slice CT. The final study group consisted of 81 patients (49 males, 32 females). Portal venous phase images were studied for the measurements. Both the reconstruction interval and thickness were 1.5 mm. Each adrenal gland was outlined manually with computer-assistant technology to calculate its volume. The maximal sectional area, length, width and thickness of each adrenal gland were also measured. Results The mean age of total population was 47.9±13.0 (range: 20-76) years. The left, right, and total adrenal gland volumes were 4.23±0.74 (range: 2.85-5.83) cm 3 , 4.26±0.86 (2.59-6.56) cm 3 , and 8.50±1.40 (5.80-11.39) cm 3 , respectively. These volumes increased with weight (r=0.381, 0.389, and 0.437 respectively, all P<0.001), height (r=0.386, P<0.001; r=0.297, P=0.007; r=0.384, P<0.001) and body surface area (r=0.406, 0.392, and 0.452, all P<0.001). There was no significant difference in left, right or total adrenal volume with regard to sex after applying General Linear Model procedure to reduce the impact of weight (F=1.304, 0.064, and 0.597, all P>0.05), nor did volume change significantly with age (r=-0.033, -0.014, and -0.026, all P>0.05). Nearly all descriptors of bilateral adrenal glands correlated with ipsilateral volume except thickness (r=-0.027, P=0.814) and width (r=0.166, P=0.138) in the left side. Among these parameters, length had a stronger correlation with volume than others in the both left (r=0.412, P<0.001) and right (r=0.516, P<0.001) adrenal glands. Conclusion Our study has defined the volume distribution and other parameters of normal adrenal glands in Chinese adults, which provide a baseline for future studies.

System Recovery-Aware Virus Propagation Model and Its Steady-State Analysis

Network structures and human behaviors are considered as two important factors in virus defense currently. However, due to ignorance of network security, normal users usually take simple activities, such as reinstalling computer system, or using the computer recovery system to clear virus. How system recovery influences virus spreading is not taken into consideration currently. In this paper, a new virus propagation model considering the system recovery is proposed first, and then in its steady-state analysis, the virus propagation steady time and steady states are deduced. Experiment results show that models considering system recovery can effectively restrain virus propagation. Furthermore, algorithm with system recovery in BA scale-free network is proposed. Simulation result turns out that target immunization strategy with system recovery works better than traditional ones in BA network.

Models for Teaching Culture in Computer-Assisted Language Learning

CALL （computer-assisted language learning） has tremendously transformed the teaching of language, with its wide application in many aspects of language teaching. However, how to integrate CALL into the teaching of culture is still rarely discussed. The purpose of the paper is to explore feasible models for teaching culture in CALL and their effects on students＇ acquisition process. Based on two fundamental pedagogical approaches （participatory pedagogy and multiliteracies pedagogy） for teaching culture, this paper proposes three pedagogical models （problem-posing model, web-quest model, and computer-supported collaborative learning model） for teaching culture in CALL. In the end, this paper illustrates a combination of the three models in real CALL setting by a cultural teaching case. A questionnaire survey and interviews are conducted to reflect on students＇ feedback, which gives an insight into possible adjustments in teaching models and the paper also proposes future possibilities in applying these models into teaching culture

Analysis on the Promotion of Computer Intelligent Office System

Based on the present condition of computer hardware and software system, office automation has been basically implemented in most companies. From a long-term perspective, the future office system also needs to be gradually upgraded with the development of technology. In this paper, the role of office automation is expounded first, and then the application model of computer intelligent office system is studied, and finally the matters needing attention in the process of companies to promote intelligent office system are analyzed. It is hoped that this paper can provide inspiration and help for further study.

Effects of user perceptions associated with perceived playfulness on their attitude toward using a netbook

A netbook, Internet-enabled and with extra portability, has been fast-growing in the domain of information technology （IT） in recent years. Compared with standardized laptops or desktop computers, a netbook＇s key features include a shrunken-down and lightweight laptop that is ＂easy to learn, easy to work, and easy to play＂. This research is to empirically test the influence of user perceptions of this new form of IT （usability, compatibility and relative advantage） associated with playfulness and attitude toward purchase intention. In addition, personal innovativeness of an individual plays an important role in the antecedents of such perceptions. A test of this model, two-stage approach, confirmatory factor analysis （CFA） and structural equation model （SEM） are employed to validate the casual model from among 227 usable respondents who have been using a laptop for more than two years. Results showed support for eleven of twelve research hypotheses, and one new path linking personal innovativeness with attitude toward using is found to be non-siznificant.

3D building modeling： A critical investigation practice to learning, analyzing and deconstruting architecture

The research deal with the reconstruction through digital 3D CAAD （Computer Aided Architectural Design） modeling of masterpieces of modem and contemporary architecture. The charm of reconstruction through digital modeling is far less than that of work done on traditional maquette, indeed, makes much deeper level of detail and specificity from knowing. We had to know many technical characteristics of the buildings beyond size, like static-structural features, physical features, economic features and others. In this way＇ the model become real-simulation, a simulated architectural model in all aspects. In addition to these aspects we deeply analyze also the formal, morphological, historical and architectural aspects. The idea is to revitalize and re-discover the logics and the rules of the projected constructions that the designer architect have invented for each masterpiece of architecture, through the comprehension of how is done. The proportional analysis of the modularity on which the design is based is mandatory subject of investigation.

A classification-based method to estimate event-related potentials from single trial EEG

A novel method based on machine learning is developed to estimate event-related potentials from single trial electroencephalography. This paper builds a basic framework using classification and an optimization model based on this framework for estimating event-related potentials. Then the SingleTrialEM algorithm is derived by introducing a logistic regression model, which could be obtained by training before SingleTrialEM is used, to instantiate the optimization model. The simulation tests demonstrate that the proposed method is correct and solid. The advantage of this method is verified by the comparison between this method and the Woody filter in simulation tests. Also, the cognitive test results are consistent with the conclusions of cognitive science.

Effects of Electroacupuncture on Hippocampal and Cortical Apoptosis in A Mouse Model of Cerebral Ischemia-reperfusion Injury

Objective: To observe the effects of electroacupuncture on hippocampal and cortical apoptosis in a mouse model of cerebral ischemia-reperfusion injury. Methods: Mouse models established by repeated cerebral ischemia-reperfusion, followed by electroacupuncture at Shenshu, Geshu, and Baihui points. The control group mice were intragastrically administered Hydergine. On day 1 and 7 post-treatment, hippocampal and cortical apoptosis was detected by terminal-deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL), and apoptosis images in the hippocampal CA1 zone and cortical area were analyzed. Results: In the model group, apoptotic cells were detected one day after treatment and some cellular fibers were disarrayed. By day 7 post-treatment, there was an increase in the number of apoptotic cells in the hippocampal CA1 region. In addition, there were apoptotic cells in the cortical area, the cortical layers were thinner with localized neuronal loss and sieve-like lymphocyte infiltration, as well as glial cell proliferation and visible infarct lesions. However, in the Hydergine and electroacupuncture groups, there was a small number of apoptotic cells. At 7 days post-treatment in the model group, field number, numerical density on area, and surface density were increased. However, in the Hydergine and electroacupuncture groups these parameters were decreased (P<0.01), with a significant difference between the two treatment groups (P<0.01). Conclusion: Electroacupuncture treatment inhibited apoptosis and provided neuroprotection.