Tomoya Horiguchi

Aiming to support the acquisition of the ability to evaluate and improve the logical validity and convincingness ofarguments, which is an important part of logical thinking, we formulated a model of argumentation based on the Toulminmodel and the deductive triangular logic model. We also implemented a learning support system based on this model andconducted a learning experiment with undergraduate and graduate students as the subjects. The results of this experimentrevealed the followings findings: (1) Learning on a system based on this model worked as an exercise, and the support of thesystem improved the subjects' understanding in some tasks. (2) For undergraduate and graduate students, the simpleargument structure of 'reinforcing uncertain data that lead to a claim with other facts' was relatively easy to understand,regardless of the type of reasoning used or whether or not it was limited. They were also able to recognize the differencebetween deduction and abduction, and make improvements according to the characteristics of each. (3) Understanding ofthe scientific reasoning of 'negating a competing hypothesis to increase the credibility of a hypothesis' was improved andmore firmly established by making the argument structure explicit with the support of the system. (4) Regarding theargument structure of 'accumulating data that leads to a claim in an abductive manner,' significant difficulties arose whenit was necessary to limit abduction by making background knowledge explicit, and the support of the system did not workeffectively. From the above, the usefulness and limitations of the argument model and learning support system proposed inthis research have become clear, and we have gained certain knowledge and insight for future improvements and practicein education.

Background: In learning mechanics, students often believe that “force is exerted on moving objects.” As this misconception called “motion implies a force” (MIF) is difficult to correct, various teaching methods have been proposed, such as showing refutational/explanatory text (Palmer & Flanagan, 1997; Takagaki, 2004), promoting students' conceptual development (Dekkers & Thijs, 1998) and epistemology‐focused instruction (Elby, 2001).Objectives: The purpose of this research is to empirically examine the effectiveness of an alternative method we have proposed for helping students overcome MIF misconceptions. The method is called the “Error‐based simulation (EBS)” that creates a counterexample to students' misconceptions by simulating erroneous phenomena based on students' incorrect ideas.Methods: We conducted a two‐year experimental implementation of EBS in mechanics classes at a technical college, and investigated the results. Students worked on the pre‐test, the exercise with EBS, the post‐test, and the delayed post‐test.Results and Conclusions: In both years, MIF‐answers (wrong answers due to MIF) in the learning task (problems learned with EBS) significantly decreased from the pre‐test to the post‐test and the delayed post‐test. The decrease in other erroneous answers was not significant. EBS was effective mainly in correcting MIF‐answers, and the effect was maintained over the long term. In the transfer task (new problems), the ratio of MIF‐answers to all erroneous answers in both the post‐test and delayed post‐test was much lower than that on the learning task in the pre‐test. These results suggest that learning with EBS not only corrected MIF‐answers but also promoted the correction of MIF misconceptions. A comparison between our results and those of other methods for correcting MIF misconceptions revealed that the effect of EBS was equal to or greater than that of other methods mentioned above.

An exponentially Increasing number of wireless-LAN (WLAN) devices In a dense environment causes a decrease in throughput owing to collisions among the devices and the lack of contiguous bandwidth. The next-generation standard of 802.11ax improves spectrum efficiency by additionally supporting 1024 (1K) QAM, OFDMA with 80+80MHz; these impose several challenges to silicon design. 1K-QAM demands extreme IQ balance with an IRR better than -50dB over a wide frequency range up to 80MHz to achieve at least -35dB RX EVM or less. Noise characteristics better than -44dBc LO integrated phase noise as well as 50dB isolation between each TRX chain are mandatory. To best make use of the essential features defined in the 11ax standard, a real-time and arbitrary spectrum-resource control capability at each access point (AP) is beneficial both in terms of further improvement in spectrum efficiency as well as communication reliability in ISM coexisting bands and legacy WLAN. Interference identification of the order of 10με while incorporating everything into a strictly limited silicon area is key to launching the advanced unique functionality. This paper presents a fully integrated 4×4 802.11abgn/ac/ax-compliant AP transceiver SoC. The chip offers frequency-dependent IQ (FD-IQ) mismatch calibration for both amplitude and phase, low-noise TX BB and multimode LO distribution techniques, and real-time interference detection including 2.4GHz inverter-type microwave (MW) ovens.

We propose a technique to modulate the pump light of phase-shift pulse Brillouin optical time domain analysis (PSP-BOTDA) with Walsh code in a nested configuration. We call it dual Walsh codes PSP-BOTDA. In this technique, two Walsh codes are each assigned to return-to-zero (RZ) and non-return-to-zero (NRZ) pulses. Simulation and experiment results have shown that the assignment of Walsh to the non-return-to-zero (NRZ) pulses even for code duration of longer than the time constant of the acoustic wave still attains the theoretical spatial resolution of the Brillouin signal, in contrast to that of previously proposed dual Golay codes PSP-BOTDA. In terms of the optical signal-to-noise ratio (SNR), we obtained a maximum of improvement of 5.4 dB, compared to the conventional technique.