一类混沌系统的非线性反馈控制

提出一种利用非线性反馈控制混沌的方法。根据动力学系统的稳定性理论确定了反馈增益的取值范围 ;采用分岔图和Lyapunov指数等数值研究 ,结果表明该方法的有效性。基于这一方法的连续或间歇反馈都能非常有效地将Logistic系统从混沌状态控制到稳定的周期状态     

经济下行、信用风险反馈和政府隐性救助

基于资产负债表分析经济下行背景下企业部门、银行和政府间信用风险传导,利用或有权益资产负债表中显性负债和隐性担保项目构建信用风险反馈模型分析银行部门和政府间信用风险反馈,最后结合我国政府对银行救助特点,分析政府对银行的隐性救助方式与救助成本之间的关系.实证结果表明货币供应量和汇率波动对上市企业部门、银行和政府间风险传导影响显著,风险通过隐性担保在银行部门和政府之间反馈了恶化两部门的信用风险,并且监管宽容会增加政府救助成本.建议政府调控货币供应量、控制汇率波动性、降低监管宽容程度、建立动态系统性风险损失准备金.     

基于反馈控制谈高校固定资产管理制度体系改进

高校固定资产规模日益扩大,管理水平亟待提高。本文剖析了目前高校固定资产管理中存在的问题,探寻了问题背后的制度体系缺陷,以反馈控制理论为基础进行了高校固定资产管理系统分析及优化,分别从政府和高校角度提出了改进管理的措施建议。     

新型低温阀门性能测试系统

针对目前国内低温阀门性能测试系统存在测试精度低、自动化程度低、低温介质消耗量大等缺点,提出了基于先 进测试技术的新型低温阀门性能自动检测系统和检测方法,介绍了其工作原理;设计了基于闭环反馈控制的阀杆开关性 能自动操作机构;采用现代控制技术,设计了深冷箱自动开关压紧机构;设计了基于光电原理的光电气泡计数器。应用 结果表明,该系统不仅具有测试精度高、自动化程度高等特点,而且可有效减少低温介质消耗量,提高测试过程的安全性。     

基于真实感框架的自然用户界面反馈设计方法

以自然用户界面的真实感框架为研究出发点,深入分析自然用户界面的反馈行为,提出一种自然用户界面的反馈设计方法。基于该方法设计并实现了一个原型系统Flying Kite。构造对比实验从主客观两个方面比较了Flying Kite系统与采用普通方法构造的K-Kite系统间的用户体验差异。实验初步验证了反馈设计方法的有效性,该方法可以显著地提升人机系统的用户体验,使自然用户界面的优势得到充分体现。     

试论突显、反馈及注意对二语输出能力的影响

突显与反馈是两种提升注意的手段，就理论层面而言，它们对二语输出能力的影响是毋庸置疑的。实证研究表明，虽然突显与反馈都会在二语输出过程中发挥作用，相对而言，反馈比突显更有利于学习者注意力的提升；两种手段若能有机结合则效果更佳，能有效促进学习者二语输出能力的提高。     

Behavioral Safety in the Food Services Industry: Challenges and Outcomes

During the course of a 6-year behavioral safety consult at a food and drink industry site, data were collected on the number of Occupational Safety Health Administration (OSHA) recordable incidents, number of lost and restricted days, and number of peer safety observations. Employees were trained to identify safe and unsafe behavior, conduct peer observations, and provide peer feedback. Data collected from observations were utilized to deliver graphic feedback. Managers were encouraged to review graphic feedback with employees weekly, provide prompts for observation, and praise employees for conducting observations. A committee composed of employees and managers met monthly to address safety concerns. Reductions in incidents were observed over the course of the behavioral safety intervention, but a reversal to baseline could not be implemented. A negative correlation was observed between number of peer observations and number of recordable incidents. Results suggest that when employees conduct peer observations more frequently, the number of recordable incidents decreases.     

基于用户反馈的Web多媒体数据源的选取

针对Web多媒体主题的特点采用用户反馈机制,提出了用户推荐可信度度量准则,准确获取了多媒体数据源核心质量维度,建立了相关的质量模型。实验结果表明,该方法在多媒体数据源选取时,准确性较高且计算量较小。     

A Causal Model of Chronic Obstructive Pulmonary Disease (COPD) Risk

Research on the etiology of chronic pulmonary disease (COPD), an irreversible degenerative lung disease affecting 15% to 20% of smokers, has blossomed over the past half‐century. Profound new insights have emerged from a combination of in vitro and –omics studies on affected lung cell populations (including cytotoxic CD8⁺ T lymphocytes, regulatory CD4⁺ helper T cells, dendritic cells, alveolar macrophages and neutrophils, alveolar and bronchiolar epithelial cells, goblet cells, and fibroblasts) and extracellular matrix components (especially, elastin and collagen fibers); in vivo studies on wild‐type and genetically engineered mice and other rodents; clinical investigation of cell‐ and molecular‐level changes in asymptomatic smokers and COPD patients; genetic studies of susceptible and rapidly‐progressing phenotypes (both human and animal); biomarker studies of enzyme and protein degradation products in induced sputum, bronchiolar lavage, urine, and blood; and epidemiological and clinical investigations of the time course of disease progression. To this rich mix of data, we add a relatively simple in silico computational model that incorporates recent insights into COPD disease causation and progression. Our model explains irreversible degeneration of lung tissue as resulting from a cascade of positive feedback loops: a macrophage inflammation loop, a neutrophil inflammation loop, and an alveolar epithelial cell apoptosis loop. Unrepaired damage results in clinical symptoms. The resulting model illustrates how to simplify and make more understandable the main aspects of the very complex dynamics of COPD initiation and progression, as well as how to predict the effects on risk of interventions that affect specific biological responses.     

Controlling epileptic seizures in a neural mass model

In an effort to understand basic functional mechanisms that can produce epileptic seizures, we introduce some key features in a model of coupled neural populations that enable the generation of seizure-like events and similar dynamics with the ones observed during the route of the epileptic brain towards real seizures. In this model, modified from David and Friston’s neural mass model, an internal feedback mechanism is incorporated to maintain synchronous behavior within normal levels despite elevated coupling. Normal internal feedback quickly regulates an abnormally high coupling between the neural populations, whereas pathological internal feedback can lead to hypersynchronization and the appearance of seizure-like high amplitude oscillations. Feedback decoupling is introduced as a robust seizure control strategy. An external feedback decoupling controller is introduced to maintain normal synchronous behavior. The results from the analysis in this model have an interesting physical interpretation and specific implications for the treatment of epileptic seizures. The proposed model and control scheme are consistent with a variety of recent observations in the human and animal epileptic brain, and with theories from nonlinear systems, adaptive systems, optimization, and neurophysiology.