Revealing Online Learning Behaviors and Activity Patterns and Making Predictions with Data Mining Techniques in Online Teaching

This study was conducted with data mining (DM) techniques to analyze various patterns of online learning behaviors, and to make predictions on learning outcomes. Statistical models and machine learning DM techniques were conducted to analyze 17,934 server logs to investigate 98 undergraduate students’ learning behaviors in an online business course in Taiwan. The study scientifically identified students’ behavioral patterns and preferences in the online learning processes, differentiated active and passive learners, and found important parameters for performance prediction. The results also demonstrated how data mining techniques might be utilized to help improve online teaching and learning with suggestions for online instructors, instructional designers and courseware developers

A reversed phase HPLC method for the analysis of nucleotides to determine 5’-PDE enzyme activity

5’-Phosphodiesterase (5'-PDE) can be extracted from barley roots and used as a catalyst in the hydrolysis of RNA to produce 5'-nucleotides. The assay of enzyme activity is essential for the production of 5'-PDE. To improve the conventional assays, we developed and validated a new method for the analysis of 5’-PDE enzyme activity using reversed phased high performance liquid chromatography (RP-HPLC). The method is based on the quantification of the four 5’-nucleotides namely cytidine 5’-monophosphate (5’-CMP), uridine 5’-monophosphate (5’-UMP), guanosine 5’-mono-phosphate (5’-GMP) and adenosine 5’-mono-phosphate (5’-AMP), produced in the enzymatic hydrolysis of yeast RNA. The optimal condition for the enzymatic hydrolysis of RNA to detect the enzyme activity was investigated. The results show that when the hydrolysis takes place at 70 oC for 30 min at pH 5.0, the hydrolysis reaction has highest yield for the four of the 5’-nucleotides. 5’-PDE demonstrated highest catalytic capability. These four 5’-nucleotides were utilized for the analysis of enzyme activity of 5’-PDE with our newly developed HPLC method. Excellent reproducibility, precision, and linearity were obtained for this HPLC method. KEY WORDS: Enzyme activity, 5’-PDE, Barley roots, Nucleotides, RNABull. Chem. Soc. Ethiop. 2010, 24(2), 167-174

Controlled Porosity in Thermochromic Coatings

Vanadium dioxide is a promising thermochromic material, seemed as the great candidate for smart window applications. The real application of VO2 requires high visible transmission (Tlum) as well as large solar modulating abilities (∆Tsol), which could not be achieved by pristine VO2 materials due to the trade-off between Tlum and ∆Tsol. Here in, the porosity design is thoroughly reviewed from the effect on modulating the thermochromic performance to the porous control and preparation. To begin with, the history, advantages, challenges and approaches to tackle the issues comprised of antireflection multilayer structure, nanothermochromism, patterning and porous design is introduced in detail. Then, the effect of porosity on improving the thermochromic performance of VO2 thin films is demonstrated using the newest experimental and simulation results. In the following, the porous control and structural synthesis, including the polymer-assisted deposition (PAD), freeze-drying, colloidal lithography as well as the dual phase transformation is summarized. Fourthly, the characterization methods, composed of scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Raman spectroscopy as well as UV-Vis-NIR spectroscopy are demonstrated. Finally, the challenges that the porous design faces and possible approaches to optimize the performance are presented

Research on the Replacement Business Tax with ValueAdded Tax of Chinese Banking Industry

As the heart of China’s financial system, the banking industry plays an important role in the nation’s economic development. Under Chinese current financial tax system, the main taxes levied to Banks are business tax (BT) and income tax. Shouldering heavy tax burden and being taxed repeatedly, such policies on the Chinese banking industry undermines the integrity of Value-Added Tax (VAT) chain, contrary to the international guiding rule that the financial industry should be lighter taxed. The defect of Chinese financial tax system makes the phenomenon that the capital accumulation rate is lower than business expansion rate. As a result, Chinese banking industry lack a foundation for further development and international competitiveness. This paper, using developed countries’ successful experiences in financial tax system for reference, in combination with China's practices, proposes to include the banks into the levying scale of VAT, handling local and central income distribution properly to consummate Chinese financial tax system reform in replacing the business tax with VATgradually