5,856 research outputs found
The role of pedagogical tools in active learning: a case for sense-making
Evidence from the research literature indicates that both audience response
systems (ARS) and guided inquiry worksheets (GIW) can lead to greater student
engagement, learning, and equity in the STEM classroom. We compare the use of
these two tools in large enrollment STEM courses delivered in different
contexts, one in biology and one in engineering. The instructors studied
utilized each of the active learning tools differently. In the biology course,
ARS questions were used mainly to check in with students and assess if they
were correctly interpreting and understanding worksheet questions. The
engineering course presented ARS questions that afforded students the
opportunity to apply learned concepts to new scenarios towards improving
students conceptual understanding. In the biology course, the GIWs were
primarily used in stand-alone activities, and most of the information necessary
for students to answer the questions was contained within the worksheet in a
context that aligned with a disciplinary model. In the engineering course, the
instructor intended for students to reference their lecture notes and rely on
their conceptual knowledge of fundamental principles from the previous ARS
class session in order to successfully answer the GIW questions. However, while
their specific implementation structures and practices differed, both
instructors used these tools to build towards the same basic disciplinary
thinking and sense-making processes of conceptual reasoning, quantitative
reasoning, and metacognitive thinking.Comment: 20 pages, 5 figure
Achieving full diversity in multi-antenna two-way relay networks via symbol-based physical-layer network coding
This paper considers physical-layer network coding (PNC) with M-ary phase-shift keying (MPSK) modulation in two-way relay channel (TWRC). A low complexity detection technique, termed symbol-based PNC (SPNC), is proposed for the relay. In particular, attributing to the outer product operation imposed on the superposed MPSK signals at the relay, SPNC obtains the network-coded symbol (NCS) straightforwardly without having to detect individual symbols separately. Unlike the optimal multi-user detector (MUD) which searches over the combinations of all users’ modulation constellations, SPNC searches over only one modulation constellation, thus simplifies the NCS detection. Despite the reduced complexity, SPNC achieves full diversity in multi-antenna relay as the optimal MUD does. Specifically, antenna selection based SPNC (AS-SPNC) scheme and signal combining based SPNC (SC-SPNC) scheme are proposed. Our analysis of these two schemes not only confirms their full diversity performance, but also implies when SPNC is applied in multi-antenna relay, TWRC can be viewed as an effective single-input multiple-output (SIMO) system, in which AS-PNC and SC-PNC are equivalent to the general AS scheme and the maximal-ratio combining (MRC) scheme. Moreover, an asymptotic analysis of symbol error rate (SER) is provided for SC-PNC considering the case that the number of relay antennas is sufficiently large
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