A Field-test of a Web Application for L2 Speaking Practice under an Uncontrolled Learning Environment for a Whole Semester

In second/foreign language speaking practice, there is limited time for students to practice, getting feedback from an experienced teacher in class. In order to remove the time constraint, computer assisted language learning systems are the first candidate, but few systems estimate learner's state, which includes their mental states and learning environments. For estimating it, it is natural to use specific peripherals or applications, but this leads to another constraint in learning environment. In addition, it is challenging to develop such a system because speaking practice, other than practice for other skills, essentially requires non-textual data. The distant goal of this study is to propose a system that generates feedback based on learners' states, without any constraints on time and place. With this goal, the purpose of this paper is to identify the basic requirements of a system for speaking under uncontrolled learning environment by a long-term field test. In this field test, a prototype system we developed was used for 15 weeks (or 1 semester) as online assignments by 28 international students taking a Japanese language course at a university. Our prototype was a browser-based web application, and learners practiced speaking using their own devices, e.g., PCs and smartphones. This field test was conducted under uncontrolled learning environment of each learner participating in the long-term online course, without ever meeting face-to-face. These settings significantly differ from those of previous studies, which are well controlled under some specific environment. Our prototype has worked with many devices, and enabled students, including those who was not able to enter our country due to the coronavirus disease 2019 pandemic, to practice speaking. Through the field test, we identified some problems, which can be happened for similar systems of speaking, and summarized into three categories: operation devices, voice recording, and data transmission. We propose a set of methods to solve these problems, which are useful for developing similar systems in actual learning environments. © 2022 ACM.

Laser frequency comb system for the InfraRed Doppler spectrograph on the Subaru Telescope

A near-infrared radial velocity (RV) survey focusing on the late-M dwarfs started in February 2019 within the framework of the Subaru Strategy Program (SSP). The InfraRed Doppler (IRD) instrument mainly consists of a high-resolution spectrometer and a laser frequency comb (LFC) system as a wavelength reference. Late-M dwarfs emit most of their energy in the near-infrared rather than in the visible. Therefore, to cover the bright absorption lines of M dwarfs, LFC provides a broadband spectrum from 970 nm to 1750 nm with a mode spacing of 12.5 GHz. It has advantages such as simple and robust frequency stabilization, an all-fiber optic configuration, and being observer friendly. The original comb spectrum just generated from highly nonlinear fibers undergoes optical processing such as spectral shaping, depolarization, and mode scrambling in multimode fiber utilization before it is input to the spectrometer. Using the IRD instrument, the IRD-SSP has made more than 100 nights of observations over the last three years. The LFC system operated stably without major trouble during this period, helping to maintain high RV accuracy. Despite the lack of direct maintenance for two and a half years due to Covid-19, the system has continued to operate without any interruption to the observations.

Effects of tourism promotion on COVID-19 spread: The case of the "Go To Travel" campaign in Japan.

Introduction: On July 22, 2020, the Japanese government launched the "Go to Travel" campaign that subsidizes 50% of personal travel expenditure to support the tourism industry under the COVID-19 pandemic. This policy was controversial from the viewpoint of infection spread and was temporarily cancelled in December 2020, though there was no statistical evidence. Methods: This is the first study that measures the extent to which this campaign increased COVID-19 cases. This study regards the campaign as a natural experiment: although Tokyo and its commuting areas experienced the same time-series trends of COVID-19 cases before the "Go To Travel" campaign, this campaign was implemented in areas outside Tokyo, but not in Tokyo. Then, the comparison (difference-in-differences) yields the campaign's effect. Results: The estimation shows that the "Go To Travel" campaign significantly raised the increment rate of cases by 23.7%-34.4% during July 30-August 4. There is no significant effect after August 5. In addition, our simulation identified the number of campaign-related cases in each city. Conclusions: Although the campaign significantly spread COVID-19, the effect was not continuous to permanently change the time-series trend.

Implementation and effectiveness of a supportive care learning collaborative for hemodialysis

Background: The objective of this study was to determine whether a learning collaborative for hemodialysis providers improved delivery of supportive care best practices. Methods: Ten U.S. hemodialysis centers participated in a hybrid implementationeffectiveness pre-post study targeting seriously ill patients between April 2019 and September 2020. The collaborative educational bundle consisted of learning sessions, communication training and implementation support. The primary outcome was change in proportion of seriously ill patients with complete advance care planning (ACP) documentation. Healthcare utilization was a secondary outcome and implementation was assessed qualitatively. Results: One center dropped out during the COVID-19 pandemic. Among the remaining nine centers, 22.9% (320/1395) of patients were identified as seriously ill in the pre-intervention period and 18.0% (226/1254) were identified in the post-intervention period. From the pre-intervention to post-intervention period, the proportion of patients with complete ACP documentation increased, and hospitalizations and emergency department visits decreased (Table). There was no difference in mortality, palliative dialysis, hospice referral or dialysis discontinuation. Screening for serious illness was widely and sustainably adopted. Goals of care discussions were adopted with variable integration and sustainment. Conclusions: Supportive care best practices were feasible to implement in hemodialysis centers and largely sustained during the COVID-19 pandemic. We observed increased documentation of ACP and lower healthcare utilization after the intervention which could reflect a combination of collaborative and pandemic effects. (Table Presented) .