Media Research Center

About: Media Research Center is a based out in . It is known for research contribution in the topics: Collaborative learning & Educational technology. The organization has 491 authors who have published 950 publications receiving 28581 citations. The organization is also known as: MRC.

Is Overshoot Caused by an Efferent Reduction in Cochlear Gain

Abstract: Under certain conditions, detection of a masked tone is improved by a preceding sound (“precursor”). This phenomenon is referred to as the “temporal effect” or “overshoot”. A prevalent model of overshoot, referred to as the “gain reduction model”, posits that overshoot is caused by efferent reduction in cochlear gain mediated by the medial olivocochlear (MOC) bundle. The model predicts that reduction in cochlear gain will reduce masking when masking is suppressive or when masking is excitatory and the signal-to-masker ratio is high. This study was aimed at testing the validity of these predictions. It consisted of two experiments. The first experiment investigated the relative contributions of suppressive versus excitatory masking to overshoot. The signal was a short 4-kHz tone pip, and the masker and precursor were limited to contain energy either only within (­on-frequency) or only outside (off-frequency) the cochlear filter around the signal frequency. The on-frequency masker would be expected to cause mainly excitatory masking, whereas masking by the off-frequency masker would be expected to be mainly suppressive. Only the off-frequency masker and precursor yielded ­significant overshoot. This suggests that measurable overshoot requires suppressive masking. The second experiment sought to quantify the effect of a precursor on cochlear ­suppression more directly by measuring the amount of suppression caused by a 4.75-kHz suppressor on a lower-frequency (4-kHz) suppressee with and without a precursor present. Suppression was measured using a forward-masking paradigm. While we found large suppression and large overshoot, we found no reduction in suppression by the precursor. This is contrary to the gain reduction model. Taken together, our results indicate that measurable overshoot requires off-frequency masking and that off-frequency overshoot must be caused by a mechanism other than MOC-mediated reduction in cochlear suppression.

Semi-automatic image and video annotation system for generating ground truth information

Abstract: Recently, techniques for automatically interpreting images or videos through machine learning based on big data have been actively studied. In this paper, we propose a semiautomatic image and video annotation system to generate ground truth information, which is essential information for machine learning of images or videos. Unlike the conventional methods for generating simple ground truth information manually, the proposed system not only provides various ground truth information such as object information, motion information, and event information, but also uses a semi-automatic image and video annotation method for fast generation of ground truth information. The ground truth information generated by the proposed system is stored in the metadata database as a form of XML. The implementation results show that the proposed system provides not only fast ground truth annotation, but also more various ground truth information compared to the existing methods.

Argumentative knowledge construction in CSCL

Abstract: Knowing how to argue is a prerequisite to participation in scientific discourse. In argumentative knowledge construction, learners collaboratively construct and engage in arguments with the goal of learning to argue within a domain. Students have difficulties, however, constructing and evaluating arguments. Computer-supported collaborative learning (CSCL) attempts to address these difficulties by providing students with additional resources and tools to visualize and guide their argumentation. This symposium presents results from empirical studies on facilitating and analyzing argumentative knowledge construction in CSCL. These studies assess the structural and conceptual quality of learners' arguments; provide sequential analyses of how learners exchange arguments in discourse, and investigate the relationship between cognitive processes of learners and the construction of arguments in discourse.