About the Authors

Jun-ichiro Watanabe

junichiro.watanabe.ws@hitachi.com

Affiliation Central Research Laboratory, Hitachi, Ltd., Tokyo, 185-8601 Japan

Nozomu Ishibashi

Affiliation Hitachi High-Technologies Corporation, Tokyo, 105-8717 Japan

Kazuo Yano

Affiliation Central Research Laboratory, Hitachi, Ltd., Tokyo, 185-8601 Japan

Competing Interests

Financial support for this study was provided by Hitachi, Ltd., and Hitachi High-Technologies Corporation. Jun-ichiro Watanabe and Kazuo Yano are current employees of Hitachi, Ltd. Nozomu Ishibashi is employed by Hitachi High-Technologies Corporation. The wearable sensor badge used in this study is a commercial product form Hitachi High-Technologies Corporation. There are no patents, products in development, or further marketed products to declare. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: JW NI KY. Performed the experiments: JW NI. Analyzed the data: JW. Contributed reagents/materials/analysis tools: NI KY. Wrote the paper: JW.