Effects of a social tutor on participation,sense of community and learning in online university courses     

Stefano Cacciamani  Donatella Cesareni  Vittore Perrucci  Giulia Balboni  Ahmad Khanlari 《British journal of educational technology : journal of the Council for Educational Technology》2019,50(4):1771-1784

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红脉钓樟种内与种间竞争关系的研究     

金则新  卢棉  蔡碧君 《台州学院学报》2003,25(3):54-57

用Hegyi的单木竞争指数模型对天台山红脉钓樟的种内、种间的竞争强度进行定量分析。结果表明:红脉钓樟种内竞争较之与其伴生树种七子花间的竞争弱。红脉钓樟种内、种间竞争强度的大小顺序为:七子花>种内>苦枥木>青钱柳>江浙钓樟>红果钓樟>阔叶蜡瓣花>榔榆>尾叶樱>柳杉。竞争木对对象木的竞争强度与对象木的个体大小服从幂函数关系,竞争强度随对象木个体大小的增大而减小;竞争强度与对象木胸径大小呈极显著的负相关关系。  相似文献   

Resource discovery in distributed digital libraries through visual knowledge navigation     

GU Qian-yi AHMAD Faisal SUMNER Tamara 《浙江大学学报(A卷英文版)》2005,6(11):1306-1311

INTRODUCTION In this paper, we present our work in the Strand Map Service (SMS), which provides concept map based browsing interfaces for resource discovery in a library independent manner within American Na- tional Science Digital Library (NSDL). As critical components of digital libraries, dis- covery systems provide interfaces that support user to search and browse for resources in digital libraries (Hall et al., 1999). The effectiveness of discovery systems has big impact on the…  相似文献   

甘肃省能源经济系统分析与优化策略研究   总被引：2，自引：1，他引：1  

杨冕  陈兴鹏  杨福霞 《资源科学》2010,32(2):359-365

能源经济系统的优化不仅是实现区域节能减排目标的重要途径,更是社会经济可持续发展的主要内容,本文以甘肃省为研究案例,基于计量经济学方法,对其经济增长与能源消耗之间的动态关系进行了定量研究;进而运用结构分解模型,对比分析了影响单位GDP能耗的主要因素。研究结果表明:甘肃省GDP与能耗总量之间存在长期的协整关系;促进甘肃省能源强度降低的主要因素是各产业能源利用效率的提高,而产业结构变动对全省能源强度降低的贡献份额较小;对能源强度降低贡献较大的为第二产业的效率份额与结构份额,而第三产业结构份额对能源强度降低的贡献为负。文章最后从产业结构优化、关键技术推进、能源结构优化三个角度提出了甘肃省能源经济系统的优化策略。  相似文献   

Generalized filtering of one-sided Lipschitz nonlinear systems under measurement delays     

Sohaira Ahmad  Muhammad Rehan 《Journal of The Franklin Institute》2017,354(13):5589-5616

This paper addresses the filtering problem for the one-sided Lipschitz nonlinear systems under measurement delays and disturbances using a generalized observer. A generalized architecture for filtering of the one-sided Lipschitz nonlinear systems with output delays is explored, which exhibits diverging manifolds, namely, the conventional static-gain filter and the dynamical filter, and can be employed to render robust stability of the filtering error dynamics. A matrix inequality based framework is obtained by employing a Lyapunov?Krasovskii (LK) functional, whose derivative is exploited through Jensen's inequality, one-sided Lipschitz condition, quadratic inner-boundedness inequality and range of the measurement delay, resulting into L₂ stability for the filtering error system. Generalized filter design for the Lipschitz nonlinear systems with delayed outputs and specific results for the delay-dependent and delay-rate-independent filtering schemes for the one-sided Lipschitz nonlinear systems are deduced from the proposed approach. Convex optimization techniques are employed to achieve a solution for the nonlinear constraints through linear matrix inequalities by employing cone complementary linearization approach. Illustrative numerical examples to demonstrate the effectiveness of proposed method are provided.  相似文献   

HPLC法测定骨愈灵片中人参皂苷Rg1和三七皂苷R1的含量   总被引：2，自引：0，他引：2  

张冕 《荆门职业技术学院学报》2009,24(2):43-46

目的：建立骨愈灵片中人参皂苷Rg1和三七皂苷R1的含量测定方法。方法：采用高效液相色谱法,乙腈-水（18：82）为流动相;流速1．0mL·min^-1;检测波长203131／1。结果：人参皂苷Rg1的回归方程为Y=2．829X＋4．167（r=0．9999,n=5）,线性范围为3．0～22．5ug;三七皂苷R1的回归方程为Y=7．580X-3．971（r=0．9996,n=5）,线性范围为1．0～7．5ug。平均回收率分别为98．95％、99．27％。结论：本方法准确、灵敏,可用于骨愈灵片的质量控制。  相似文献   

Human governance: A neglected mantra for continuous performance improvement     

Arfah Salleh  Aziuddin Ahmad  Naresh Kumar 《Performance Improvement》2009,48(9):26-30

Every individual should be entrusted with an internal driver to strive their best towards achieving their potential and to manifest their performance through innovative means. This can be reached only under circumstances where the abstract human values and principles are recognized and indoctrinated in the culture. The strategies discussed in this article will serve as input in proposing the areas of focus toward the practice of human governance.  相似文献   

Building a customized module for the treatment of drug addiction under the remedial programs to be implemented on inmates at the drug rehabilitation centers in Malaysia     

Jamaludin Ahmad Tajularipin Sulaiman Saifuddin Kumar Abdullah Junaidi Shamsuddin 《美中教育评论》2009,6(11):57-64

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Practising mental rotation using interactive Desktop Mental Rotation Trainer (iDeMRT)     

Ahmad Rafi  Khairulanuar Samsudin 《British journal of educational technology : journal of the Council for Educational Technology》2009,40(5):889-900

An experimental study involving 30 undergraduates (mean age = 20.5 years) in mental rotation (MR) training was conducted in an interactive Desktop Mental Rotation Trainer (iDeMRT). Stratified random sampling assigned students into one experimental group and one control group. The former trained in iDeMRT and the latter trained in conventional condition. A multifactorial pretest posttest design procedure was used and data were analysed using two-way analysis of covariance. Overall, there was substantial improvement in MR accuracy. Main effects of training and gender were observed, indicating that iDeMRT group and boys outperformed the control group and girls respectively. In addition, an interaction between training method and gender was present, indicating that boys were more accurate when trained in iDeMRT and performed moderately in conventional method. Female participants achieved equivalent improvement gain in MR accuracy regardless of the training conditions used. For the speed measure of MR, no appreciable improvement was observed after training.  相似文献   

Higher education in Federally Administered Tribal Areas of Pakistan after 9/11： Problems and prospects     

Syed Hafeez Ahmad Fatima A. Junaid 《美中教育评论》2010,7(5):55-65

The troubled state of affairs in the Federally Administered Tribal Areas （FATA） of Pakistan portends serious repercussions and grave consequences, destined to affect education particularly higher education in the entire tribal belt. Ironically, no extensive study has been conducted, to investigate those dimensions of FATA higher education which have been adversely affected in the aftermath of 9/11. This exploratory study examines those areas which have been badly affected as a result of current turmoil. In fact, the higher education in FATA has its own peculiar dynamics. Inherently, the entire tribal region has very few well-maintained and properly equipped colleges. Lack of adequate educational facilities, multiplied poor security environment has aggravated the entire situation. Law and order situation in the region has undermined the already dilapidated monitoring mechanism of education department. This state of affairs provides breeding ground for extremist propensities and radical tendencies. In reality, very little attention has been devoted to reform the education system in tribal areas. The whole set up needs to be rehabilitated by taking recourse due to the proactive role of international community. The paper concludes with recommendations for policy makers besides offering new avenues for further research.  相似文献