Task Complexity and Variation in L2 Learner’s Oral Discourse

There are many factors which affect the L2 learner’s performance at the levels of phonology, morphology and syntax. Consequently when L2 learners attempt to communicate in the target language, their language production will show systematic variability across the above mentioned linguistic domains. This variation can be attributed to some factors such as interlocutors, topic familiarity, prior knowledge, task condition, planning time and tasks types. This paper reports the results of an on going research investigating the issue of variability attributed to the task type. It is hypothesized that the particular type of task learners are required to perform will result in variation in their performance. Results of the statistical analyses of this study investigating the issue of variation in the performance of twenty L2 learners at the English department of Tabriz University provided evidence in support of the hypothesis that performance of L2 learners show systematic variability attributed to task

Compressed sensing and undersampling k-space

In the field of medical imaging, one of the most important concepts consists of the creation of the image from an obtained signal. The creation of the image is broken down into a subset of tasks. The first is the basic concept of isolating the element crucial to creating an image. One example is the isolation of different atoms in different modalities, for example PET or SPECT. Second, is using the intrinsic properties of these atoms to create a signal that can be recorded, this is done by magnets, gradients, coils, and other technological advances specific to other imaging modalities. Third, is the method used to record the signal. This can be done in many different ways, including but not limited to, radon space and k-space. Last but not least is the transform of the data in their respective spaces into images that are read by technologists. What is described here is, a very simple explanation for the process that different modalities go through in order to create an image. This review paper will be focused mainly on k-space acquisition and the different ways that the acquisition of k-space and image creation can be accelerated to improve patient time spent in the machine

Technical note: Effects of free-surface on design charts for open channels

Normal depth is an important parameter for the design of channels and canals. For rectangular, trapezoidal, and circular channel sections it is possible to express normal depth by a trial-and-error procedure or analytically. However, the effects of free-surface on the design charts for determination of the normal depth are not investigated. In this paper, graphical solutions of normal depth for the rectangular, trapezoidal, and circular cross-sections have been obtained in the non-dimensional form. To evaluate the resistance effects of the free-surface in the calculation of the normal depth, the dimensionless-form of Manning’s equation with free-surface weight factor is introduced herein. The design charts reported previously were modified.Keywords: Open-channel flow; normal depth; free-surface effec