价值链分析:从战略的角度看在线学习

[译者按]国际著名远程教育专家、加拿大阿萨巴斯卡大学(公开大学)特里·安德森教授和同事法希·埃劳米的新著<在线学习的理论与实践>(Theory and Practice of Online Learning,Athabasca University,2004)收录了16篇论文,作者全部是阿萨巴斯卡大学的教师和研究者,他们都是20世纪90年代中期以来阿萨巴斯卡大学为了应对日益裁减的政府资助和生源的锐减而进行大规模的教育改革的实践者和见证人,这些文章既有经验总结又有前瞻性的思考,对我国的远程教育事业不无借鉴价值.现将埃劳米的文章译成中文,以飨读者.     

在线学习的理论与实践

本刊今年第3期刊登了记者对国际知名远程教育专家、加拿大阿萨巴斯卡大学特里·安德森教授的专访。安德森教授在专访中提及他和同事法希·埃劳米的新著《在线学习的理论与实践》,“希望能得到我们中国朋友的青睐和欣赏”。该书收录了16篇论文,作者全部是阿萨巴斯卡大学的教师和研究者,也都是20世纪90年代中期以来阿萨巴斯卡大学为了应对日益裁减的政府资助和生源的锐减而进行大规模教育改革的实践者和见证人,这些论文既有经验总结又有前瞻性的思考,对我国的远程教育事业不无借鉴价值。鉴于此,本刊特邀肖俊洪先生谨将该书两位主编所撰写的“引言”中的有关全书内容概要的部分译成中文,以飨读者。     

Involvement of Depressive Catecholamines as Thrombosis Risk/Inflammatory Markers in Non-Smoker,Non-Obese Congestive Heart Failure,Linked to Increased Epidermal Growth Factor-Receptor (EGF-R) Production

The EGF-R, also known as HER-1 or erbB-1 (EGF-R/HER-1/erbB-1), is a member of the human epithelial receptor tyrosine kinase family. sEGF-R is considered to play a role in cardiac (patho)physiology. We aimed to investigate whether soluble EGF-R is increased in congestive heart failure (CHF) patients and if related to disease severity. Soluble EGF-R, vitamin D, parathyroid hormone (PTH) was studied, and being evaluated in relation to Ca²⁺, lipids, hsCRP, fibrinogen, serotonin, norepinepherine (NE). The study compared non-smoker, non-obese male CHF patients (n = 50) with age and gender-matched essential hypertension (HTN) patients (n = 20). Moreover, comparison with healthy control volunteers (n = 20) were employed. EGF-R/HER-1/erbB-1 was higher (P = 0.013) in 50 CHF male patients mean 12 ± 0.7 fmol/ml, than in 20 HTN, 9.25 ± 0.6 fmol/ml or in 20 controls, 6.25 ± 1 fmol/ml. Serum EGF-R levels correlated positively with hsCRP and NE, and were highest among CVD patients (n = 70) as well as negatively with vitamin D and HDL-C. EGF-R/HER-1/erbB-1 levels are increased in HTN and more in CHF patients. This study confirms a strong association between catecholamines as well as EGF-R/HER-1/erbB-1 levels with PTH and low vitamin D levels, being related to hyperlipidemia and inflammation (hsCRP and fibrinogen) in CVD. Moreover, contributing to the complex process of the inflammatory component of atherosclerosis in hypertensive patients that leads eventually to CHF.     

Decentralized optimal controller design for multimachine power systems using successive approximation approach

In this paper, we propose to develop algorithmically and implement a nonlinear decentralized optimal control for multimachine power systems, based on a successive approximation approach for designing the optimal controller with respect to quadratic performance index. The advantage of this approach is to transform the high order coupling nonlinear two-point boundary value (TPBV) problem into a sequence of linear decoupling TPBV problem, which uniformly converges to the optimal control for nonlinear interconnected large scale systems. We apply this approach to a 3-machine power system which generators are strongly nonlinear interconnected, and containing possible uncertainties on the parameters. We demonstrate clearly via advanced simulations that this approach brings better performances than other decentralized controller, improving effectively transient stability of these power systems in few iterative sequences for different cases of perturbations.