Statistical Machine Learning for Automatic Assessment of Physical Activity Intensity Using Multi-axial Accelerometry and Heart Rate

This work explores the automatic recognition of physical activity intensity patterns from multi-axial accelerometry and heart rate signals. Data collection was carried out in free-living conditions and in three controlled gymnasium circuits, for a total amount of 179.80 h of data divided into: sedentary situations (65.5%), light-to-moderate activity (17.6%) and vigorous exercise (16.9%). The proposed machine learning algorithms comprise the following steps: time-domain feature definition, standardization and PCA projection, unsupervised clustering (by k-means and GMM) and a HMM to account for long-term temporal trends. Performance was evaluated by 30 runs of a 10-fold cross-validation. Both k-means and GMM-based approaches yielded high overall accuracy (86.97% and 85.03%, respectively) and, given the imbalance of the dataset, meritorious F-measures (up to 77.88%) for non-sedentary cases. Classification errors tended to be concentrated around transients, what constrains their practical impact. Hence, we consider our proposal to be suitable for 24 h-based monitoring of physical activity in ambulatory scenarios and a first step towards intensity-specific energy expenditure estimators

Enhancing web-based learning resources with quizzes through an Authoring Tool and an Audience Response System

Quizzes are among the most widely used resources in web-based education due to their many benefits. However, educators need suitable authoring tools that can be used to create reusable quizzes and to enhance existing materials with them. On the other hand, if teachers use Audience Response Systems (ARSs) they can get instant feedback from their students and thereby enhance their instruction. This paper presents an online authoring tool for creating reusable quizzes and enhancing existing learning resources with them, and a web-based ARS that enables teachers to launch the created quizzes and get instant feedback from the class. Both the authoring tool and the ARS were evaluated. The evaluation of the authoring tool showed that educators can effectively enhance existing learning resources in an easy way by creating and adding quizzes using that tool. Besides, the different factors that assure the reusability of the created quizzes are also exposed. Finally, the evaluation of the developed ARS showed an excellent acceptance of the system by teachers and students, and also it indicated that teachers found the system easy to set up and use in their classrooms.

The Guild of Scholars in the Episcopal Church. : a statement of its organization, history, purpose, and activities : with a foreword by the Presiding Bishop

Mode of access: Internet.

Review of international geothermal activities and assessment of U.S. industry opportunities /

"LA-11066-MS ... UC-66."

Section recommendations on retirement roles and activities; with related recommendations from other sections and special concerns sessions.

Cover title: Retirement roles and activities.

A Tamil hand-book : or Full introduction to the common dialect of that language on the plan of Ollenndorf and Arnold, for the use of foreigners learning Tamil, and of Tamilians learning English; with copious vocabularies (Tamil-English, and English-Tamil,) appendices containing reading lessons, analyses of letters, deeds, complaints, official documents.

7th ed. published under title: A handbook of the Tamil language.

The Arya Samaj : an account of its origin, doctrines, and activities, with a biographical sketch of the founder /

Includes index.

Investigation of lobbying on utility holding company bills : hearings, Seventy-fourth Congress, first session, on H. Res. 288, a resolution authorizing and directing the Committee on Rules to investigate lobbying activities with respect to utility holding companies.

Hearings held July 9-17, 1935.

Performance management : aligning employee performance with agency goals at six Results Act pilots : report to the Chairman, Subcommittee on Civil Service, Committee on Government Reform and Oversight, House of Representatives /

"B-275942"--P. 1.