Towards a Real Virtual Classroom

I presented the paper at the conference, and attended the keynote speeches and some sessions of presentation of others. About the ideas and system I presented, many people agreed with me that online education does has some shortcomings compared to face-to-face education, and agreed that the current online education practice needs to be improved to address those shortcomings. They suggested that it would be better to use other social media such as facebook, in addition to online forum and chat.Distance education is well regarded as a better way to bring education to those who are unable to attend classes at traditional schools and universities. In recent years, new Web technologies and systems such as Ajax, RSS, Wikis, blogs, social networks, online image and video sharing, online whiteboard and mind maps have made distance education more efficient and effective. However, in today distance education practice, distance learners still cannot get some of the benefits that traditional classrooms have offered. In this paper, we present a Web-based course delivery system that can provide a classroom like environment to learners distributed across the Web. Within such a system, learners are more closely connected, and helps can come more timely from their peers or the instructor and tutors. We discuss the design and architecture of the system, as well as the implementation

Cloud Computing-based IT Solutions For Organizations with Multiregional Branch Offices

I chaired a session in the morning of April 28, and then presented my paper in the afternoon. There were exciting discussions after my presentation. People in the information and information system management area are interested in the cloud-computing scheme, but they are more concerned with the security issues that may arise. So, some critical evaluation of the new IT solution must be done fully before adopt it for an organization. During the conference, I had talks with other attendees about AU. They are very interested in AU, often surprised at our success. Prof. Grant at the Ryerson University told me that last year she met one of our students we sent to Case IT 2010 competition at SFU, and she got a very good impression of and feedback about AU from the student. This should serve as a proof that we should more often send our students to national or international events such as Case IT (we have sent a team in two consecutive years since last year), HackUs (we sent one student to competition this year). Those students may become good convincing advocates of AU and AU programs. She also mentioned that she had offered one session of teaching through distance learning, and she had some good feedback from the students. So, she would like to do more. This lets me wonder what would happen to AU if more and more professors at other universities start to offer their courses through DE, as an option for students who cannot attend the classes at campus.One of the most significant phenomena of the new century is globalization. As business goes global, multiregional branch offices are needed and networked computing and information services must then be established for those branch offices. In this paper we investigate a cloud computing based approach to the rapid deployment of computing and information services for organizations with multiregional branch offices. We first take a look at the general process leading to the deployment of Computer and Information Technology (CIT) services for organizations, and then present some cloud computing-based solutions for organizations with multiregional branch offices, followed by discussions about their key features as well as issues and concerns surrounding the proposed IT solutions. An important contribution of this paper is a generalized view of the cloud computing-based approach, which may be used as guidance in implementing and deploying such IT solutions

A Framework for Enabling Incidental Learning on the Web

With the support of this A&PDF fund, I was able to attend International Conference on Cyber Crime and Computer Forensic 2013The 2013 International Conference on e-Learning, e-Business, Enterprise Information Systems, and e-Government held in Las Vegas, USA, and presented a paper titled A Framework for Enabling Incidental Learning on the Web. From the feedback's from the attendees, I see both the values of the research and the challenges ahead. This has made me become more diligent to work on the topic.Incidental learning is learning something without intent, which usually happens at the time that is not dedicated to learn that thing. Examples of such time include work, game play and activities for leisure. In today’s life of many people, a lot of time is spent on the surfing the Web. Should incidental learning be effectively implemented for individuals using the Web, it would make learning more effective for many. This can be especially true for adult learners since they most likely have less time dedicated to learning, or don’t have any dedicated time for learning at all. In this paper we present a framework for enabling incidental learning on the Web. The framework identify six key elements for incidental learning on the web, describe a general process of incidental learning, two types of incidental learning and nine scenarios of incidental learning on the web. Finally, the framework prescribes a list of theories and essential technologies that are important for enabling incidental learning on the web

3D Numerical Simulation of Shield Tunnel Subjected to Swelling Effect Considering the Nonlinearity of Joint Bending Stiffness

In this paper, the authors developed a three dimensional shell-spring numerical model of a shield tunnel, in which the elastic shell elements were adopted to model the segments and the spring models were used for the simulation of the segmental joints. The highlight of this research is that the non-linearity of the joint bending stiffness was taken into consideration, which was first determined through the numerical simulation by using a refined 3D continuum model of the segment-joint structure. The automatic iteration of the joint bending stiffness was achieved through programming with the ANSYS ADPL software. Based on a specific engineering example, a 3D continuum-shell-spring model was established to analyze the internal forces of shield tunnel segmental linings subject to swelling soils. The developed numerical model and its application in the analysis of the internal forces of shield tunnel segmental linings in swelling ground will provide useful reference and guidance for the numerical calculation in similar engineering projects in future

Research on variogram analysis method for 3D modeling of sandstone reservoir

Analysis of variogram is a necessary step in 3D stochastic modeling, and different settings of variograms can directly affect the final distribution of model attribute. How to optimize the setting of variogram parameters by unit and facies type has become a key step in geological modeling. This article focuses on the reservoir within sedimentary background of fluvial-deltas in the layer SII7+8 which develops multiple sedimentary microfacies, such as fluvial channels, abandoned fluvial channels, flood plains, and natural levee with strong heterogeneity, so as to study the impact of changes of the variogram parameters on the simulation results of reservoir properties, in order to explore the analysis method of the variogram. On this basis, the reservoir is divided into 3 types of sand bodies and 11 types of sedimentary microfacies based on net pay thickness, sedimentary environment, and main sand scale and morphology. The distribution characteristics and extension scale of different facies types on the plane are classified and studied, in order to determine the characteristic parameters of the variogram of different types of sand bodies, accurately simulate the distribution characteristics of reservoir physical property, and further improve the accuracy of the 3D attribute model

Composition and structure of extraction residue of direct coal liquefaction residue and recycle of active phase of iron catalyst

In order to solve the problem of iron source supply for large-scale direct liquefaction catalyst, and meanwhile realize the harmless separated-utilization of extraction residue from coal liquefaction, this paper conducted a research on the recovery of iron catalyst from extraction residue, and explored the feasibility of enriching recovery of iron catalyst by using physical magnetic separation method. Firstly, the characterization methods, such as particle size analysis, XRF, XRD, SEM, TG, SEM-EDX, were used to comprehensively characterize and analyze the physical and chemical properties of the extraction residue, and therefore determine the contents and existence forms of iron catalyst. From the results analysis, it can be seen that the extraction residue from industrial equipment is mainly composed of carbon in unreacted coal and residual carbon, volatile matter and ash, with uniform particle size and no agglomeration. The mass fraction of iron is 5.96%, and the iron species still exist as the active phase of paramagnetic Fe1−xS, which doped and coated by unreacted coal and residual asphalt, and uniformly mixed and distributed in the extracts with various elements such as Ca, Si, Al, O, etc. On this basis, four types of magnetic separation equipment were selected for magnetic separation enrichment under different magnetic field strengths, and the enriched samples were then used as catalysts for direct coal liquefaction reaction to investigate their performances in direct liquefaction reaction. The experimental results show that：On the one hand, the high gradient magnetic force generated by the wet vertical ring pulsating high gradient magnetic separator is applied to the magnetic catalyst fine powder. Together with using water as dispersion medium and washing medium, the fine separation of iron catalyst powder from extraction residue was realized more effectively. With the magnetic field strength of 640 000 A/m, the material enrichment rate of the iron-containing catalyst was 10.48%, and the mass fraction of iron was 11.37%, the extraction oil yield of high-pressure autoclave 41.96%, which was 7.17% higher than that without the catalyst, and 8.99% higher than that with the extraction residue. It can be mixed into fresh catalyst to achieve an effective reuse, to some extent solving the problem of catalyst iron source shortage

An efficient process for wastewater treatment to mitigate free nitrous acid generation and its inhibition on biological phosphorus removal

Free nitrous acid (FNA), which is the protonated form of nitrite and inevitably produced during biological nitrogen removal, has been demonstrated to strongly inhibit the activity of polyphosphate accumulating organisms (PAOs). Herein we reported an efficient process for wastewater treatment, i.e., the oxic/anoxic/oxic/extended-idle process to mitigate the generation of FNA and its inhibition on PAOs. The results showed that this new process enriched more PAOs which thereby achieved higher phosphorus removal efficiency than the conventional four-step (i.e., anaerobic/oxic/anoxic/oxic) biological nutrient removal process (41 ± 7% versus 30 ± 5% in abundance of PAOs and 97 ± 0.73% versus 82 ± 1.2% in efficiency of phosphorus removal). It was found that this new process increased pH value but decreased nitrite accumulation, resulting in the decreased FNA generation. Further experiments showed that the new process could alleviate the inhibition of FNA on the metabolisms of PAOs even under the same FNA concentration

A recombinant avian antibody against VP2 of infectious bursal disease virus protects chicken from viral infection

【Abstract】A stable cell-line was established that expressed the recombinant avian antibody (rAb) against the infectious bursal disease virus (IBDV). rAb exhibited neutralization activity to IBDV-B87 strain in DF1 cells. The minimum rAb concentration required for inhibition of the cytopathic effect (CPE) was 1.563 μg/mL. To test the efficacy of rAb, a 168-h cohabitation challenge experiment was performed to transmit the disease from the chickens challenged with vvIBDV (HLJ0504 strain) to three test groups of chickens, i.e. (1) chickens treated with rAb, (2) chickens treated with yolk antibody, and (3) non-treatment chickens. The survival rates of chickens treated with rAb, yolk antibody and without treatment were 73%, 67% and 20%, respectively. Another batch of chickens was challenged with IBDV (BC6/85 strain) and then injected with rAb (1.0 mg/kg) 6, 24 and 36 h post-challenge. Non-treatment chickens had 100% morbidity, whereas those administered with rAb exhibited only 20% morbidity. Morbidity was evaluated using clinical indicators and bursal histopathological section. This study provides a new approach to treating IBDV and the rAb represents a promising candidate for this IBDV therapy.This research was supported by Heilongjiang province project of applied technology research and development (2013GC13C105) and The National Natural Science Fund biologic science base improve program of research training and capacity (J1210069/J0124)

The characteristics of hematopoietic stem cells from autoimmune-prone mice and the role of neural cell adhesion molecules in abnormal proliferation of these cells in MRL/lpr mice

Background and Objectives Using various animal models for autoimmune diseases, we have previously shown that such diseases are stem cell disorders.1 In order to understand how autoimmune diseases develop, we investigated the distinct qualitative differences between hematopoietic stem cells (HSC) from normal and autoimmune-prone mice.Design and Methods We studied the major histocompatibility complex (MHC) restriction between HSC and stromal cells in vitro and in vivo. We also examined the ability of HSC to adhere to a stromal cell line and, using flow cytometry, analyzed the expression of various adhesion molecules in HSC before and after the onset of autoimmune disease. In addition, the effect of antibodies to anti-adhesion molecules on the proliferation of HSC was investigated.Results The abnormal HSC of MRL/lpr mice showed no MHC restriction (or preference) with stromal cells either in vitro or in vivo, although there was MHC restriction between normal HSC and stromal cells, as we previously reported.2,3 The abnormal HSC of MRL/lpr mice exhibited enhanced adhesion to stromal cells in vitro and expressed a higher amount of adhesion molecules such as neural cell adhesion molecule (NCAM). Interestingly, the proliferation of HSC in MRL/lpr mice was significantly suppressed by anti-NCAM monoclonaal antibodies.Interpretation and Conclusions Abnormal HSC of MRL/lpr mice are more resilient than normal HSC. Furthermore, among various adhesion molecules, only NCAM shows increased expression on HSC of MRL/lpr mice after the onset of autoimmune diseases, and these molecules contribute to the enhanced proliferation capacity of abnormal HSC in MRL/lpr mice. The present findings suggest that there are intrinsic qualitative differences between HSC from normal and autoimmune-prone MRL/lpr mice