The development of collaborative learning practices in an online language course

PhD ThesisThe success or failure of a course is, to a great extent, dependent on the level of motivation and commitment of the learners. Such motivation and commitment are, however, difficult to establish and maintain, especially in an on-line course. Social relations within a class, and the willingness of learners to collaborate with each other, have an important role to play, but the constraints of time and distance are obstacles to fostering such social relations among students enrolled in on-line courses. It is not easy to encourage students to be collaborative when they are accessing the course at different times, from different locations. This thesis, however, seeks to demonstrate that the variety and complexity of the technologies used to deliver an on-line learning experience can help to overcome these challenges. When introduced and used in appropriate ways, the software, internet tools, even the data collection program used for statistical analysis can actually encourage and enhance participants' motivation to interact and learn in collaborative ways. This thesis is concerned with an on-line course created and delivered by the researcher, the aim of which was to foster a collaborative learning environment in which participants felt confident enough to share their work with others, and to offer and receive comments on their assignments. The primary aim was therefore not the direct teaching and learning of language, but the fostering of an environment in which the students felt comfortable working with the technology and with each other, as a pre-requisite for the acquisition of language through content-based activities. The study did not dwell on the effects of collaboration on language development but focused, rather, on how individual students collaborate in an online, e-learning course, what forms this collaboration takes, and how the pattern of collaboration changes as the course progresses. This focus allowed the researcher to look at ways collaboration affected the persistence and retention challenges of on-line learning experience. The course was designed for students learning EFL at a university in Korea. It lasts one semester, and is delivered using a virtual learning environment (VLE) program developed by the university. The course consists of 15 units to be completed at the rate of one a week. Each unit focuses on a different topic and consists of a reading passage and a listening exercise. This is followed by some writing activities, including a weekly written report, and recording assignments. The researcher was the instructor for this course, and made special interventions using appropriate technology (sometimes e-mail, other times Skype to make it more personal) to encourage students to work in pairs, and in group discussions, and to post their work in the VLE so that others could read and comment on it. The current study reports on the experience of running the course with one group of 47 Korean university students. Data was gathered from the learners‟ journals, their assignments, feedback and comments posted on the web board, and emails to the instructor. The VLE also recorded statistics showing the students‟ usage of the different components of the course, and how their use of these components changed and fluctuated as the course progressed. The results showed that in the process of completing the course the majority of the learners reported a strong sense of “belonging” to a learning community, developing a close rapport with other learners by sharing their work, exchanging comments and taking part in discussions. Students felt proud of their work as well as of the process of working together with other learners. In particular, the results suggest that opportunities for social interaction and feedback play a crucial role in developing the emotional connection which helps to create a collaborative learning environment and support an effective learning community. The evidence suggests that the appropriate use of technology when delivering an on-line course may, in fact, encourage collaboration because of two phenomena that are not always evident in a traditional, place-based classroom. These are anonymity and reciprocity. Anonymity makes it easier for students to share their work and ideas because, if a contribution is embarrassing, it may have less negative effect than in a face-to-face exchange. Reciprocity refers to the natural inclination of a student, having learned from others in the VLE, to give something back to the community

Identification of parameter matrices using estimated FRF variation

This study presents an analytical method to predict the dynamic parameters of actual structure from measured FRF (Frequency Response Function) data. The inconsistency due to modeling errors between the actual structure and the finite element model exists. The number of measured data is less than the one of a full set of dofs and should be expanded to estimate the parameters. Considering that the stiffness and mass matrices are related with the real part of the expanded FRF data and the damping matrix with the imaginary part, the variation in the parameter matrices is evaluated. A numerical example evaluates the appropriateness of the proposed method

Damage detection based on the internal force or deformation variation

The presence of damage in an intact structure leads to the change in internal force and deformation due to stiffness deterioration in the region of damage. This study proposes modelbased damage detection methods by deriving the mathematical formulation to describe such changes. The force and deformation variations between the undamaged and damaged systems are derived by minimizing the variation in dynamic strain energy with respect to the internal force and deformation vectors, respectively. They are expressed by the product of a coefficient matrix and the external force vector, and the product of a coefficient matrix and the displacement vector, respectively. Taking singular value decomposition (SVD) on the coefficient matrices of rank-deficiency, this study identifies the damaged elements as belonging to the set of elements whose internal forces or deformations between two adjacent nodes of finite element model are not changed. The validity of the proposed methods is illustrated in a simple application

General and Tissue Specific Gene Regulation by the WNT Signaling Pathway in Drosophila.

Secreted proteins of the Wnt family act through a conserved signaling cascade to regulate gene expression. While many genes are regulated by this pathway in a cell-specific manner, some targets are ubiquitously activated. This thesis explores both modes of regulation by Wnt signaling using the fruit fly, Drosophila melanogaster as a model. The naked cuticle (nkd) gene is activated by Wnt signaling in all tissues examined and encodes a feedback antagonist of the pathway. To learn more about its activation by Wg, we identified several cis-regulatory Wg response elements (WREs) in the nkd locus. These nkd-WREs, two from the upstream intergenic region and another from the first intron of the nkd gene, are named UpE1, UpE2 and IntE, respectively. When the three WREs are tested simultaneously in flies, they largely recapitulate the pattern of endogenous nkd in multiple tissues. The individual WREs show distinct but overlapping patterns in various tissues. These data suggest that nkd requires multiple tissue-specific WREs to fully respond to the Wg signal. The importance of the WREs was confirmed by generating flies with a deletion in these elements, which significantly reduces the expression of nkd in several tissues. To explore the mechanism of gene-specific regulation by Wnt signaling, I characterized two related nuclear proteins, Split ends (Spen) and Spenito (Nito). Spen was previously shown to be required for regulation of some Wnt targets but the role of Nito had not been explored. I found that simultaneous depletion of spen and nito by RNA interference resulted in a greater reduction in activation of some Wnt targets than knockdown of either gene alone. This suggests that Spen and Nito act redundantly in Wnt signaling. Even with simultaneous knockdown of spen and nito, several Wnt targets are still activated normally. Biochemical analysis in cultured cells indicates that Spen and Nito are not required for formation of the TCF-Armadillo complex that is known to activate target gene expression. These data indicate that Spen and Nito are gene-specific regulators of the pathway that act downstream of TCF-Armadillo.Ph.D.Molecular, Cellular, and Developmental BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/60792/1/jhcz_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/60792/2/jhcz_1.pd

Epidemiological Aspects of Exotic Malaria and Dengue Fever in Travelers in Korea

In order to compare the epidemiological aspects of exotic malaria (EM) and dengue fever (DF) imported by travelers in Korea, we have analyzed the current state both of the disease incidence and related risk factors. A total of 345 cases of EM occurred between 2001 and 2008 in Korea, and the average incidence rate per 100,000 population was 0.091. A total of 252 of DF cases occurred during the same period, and its rate was 0.063. While most of the EM and DF prevalence occurred in summer, prevalence in spring and winter was more prominent for EM (P < 0.05 ~ P < 0.01), while outbreaks in summer were more frequent for DF (P < 0.01). In Korea, more males were infected with EM and DF than females (P < 0.01). The remarkable difference between gender distributions in Korea is believed to reflect cultural differences in terms of work and travel. In both diseases, the manhood age bracket (20 - 39 years old) is possible due to increased oversea activities and travel. Moreover, reported EM cases in several prefectures in the regions of Asia and Africa were widely spread by the appropriate vector of mosquitoes, while the vectors of DF in the region of Asia are limited

Transplantation of Adipose Derived Stromal Cells into the Developing Mouse Eye

Adipose derived stromal cells (ADSCs) were transplanted into a developing mouse eye to investigate the influence of a developing host micro environment on integration and differentiation. Green fluorescent protein-expressing ADSCs were transplanted by intraocular injections. The age of the mouse was in the range of 1 to 10 days postnatal (PN). Survival dates ranged from 7 to 28 post transplantation (DPT), at which time immunohistochemistry was performed. The transplanted ADSCs displayed some morphological differentiations in the host eye. Some cells expressed microtubule associated protein 2 (marker for mature neuron), or glial fibrillary acid protein (marker for glial cell). In addition, some cells integrated into the ganglion cell layer. The integration and differentiation of the transplanted ADSCs in the 5 and 10 PN 7 DPT were better than in the host eye the other age ranges. This study was aimed at demonstrating how the age of host micro environment would influence the differentiation and integration of the transplanted ADSCs. However, it was found that the integration and differentiation into the developing retina were very limited when compared with other stem cells, such as murine brain progenitor cell

Microfiber-microcavity system for efficient single photon collection

Funded by the National Research Foundation of Korea (NRF) grant (MSIP) (NRF-2007-341-C00018, NRF-2014M3C1A3052567); State of Bavaria.Single photon sources are key components for various quantum information processing. For practical quantum applications, bright single photon sources with efficient fiber-optical interfaces are highly required. Here, bright fiber-coupled single photon sources based on InAs quantum dots are demonstrated through the k-vector matching between a microfiber mode and a normal mode of the linear photonic crystal cavity. One of the modes of the linear photonic crystal cavity whose k-vector is similar to that of the microfiber mode is employed. From independent transmission measurement, the coupling efficiency directly into the fiber of 58% is obtained. When the quantum dot and cavity system is non-resonantly pumped with 80 MHz pulse train, a raw count rate of 1.81 MHz is obtained with g(2)(0) = 0.46. Resonant pump is expected to improve the rather high g(2)(0) value. Time-resolved photoluminescence is also measured to confirm the three-fold Purcell enhancement. This system provides a promising route for efficient direct fiber collections of single photons for quantum information processing.PostprintPeer reviewe