GetMobile MOBILE COMPUTING & COMMUNICATIONS REVIEW Volume 21, Issue 2 • June 2017 CONTENTS 3 Message from the Editor-in-Chief 16 22 (ALMOST) UNPUBLISHABLE HIGHLIGHTS 5 RESULTS 22 EmotionCheck: A Wearable Device 16 Experiences Deploying an to Regulate Anxiety through False EXPERIMENTAL METHODS Always-On Farm Network Heart Rate Feedback 5 How Do You Know If 85% Accuracy Is Good Enough for Your Application? 26 9 31 26 HemaApp: Noninvasive Blood Screening of Hemoglobin Using Smartphone Cameras MOBILE PLATFORMS 9 Beyond Reality: Head-Mounted 31 Who Are the Smartphone Users? Displays for Mobile Systems Identifying User Groups with Researchers Apps Usage Behaviors 35 Interpretable Machine Learning for Mobile Notification Management: An Overview of PrefMiner 35 2 GetMobile June 2017 | Volume 21, Issue 2 MESSAGE FROM THE EDITOR-IN-CHIEF CONTRIBUTORS EDITOR-IN-CHIEF IN THIS ISSUE, we highlight four papers Eyal de Lara, University of Toronto from ACM UbiComp 2016. MANAGING EDITOR Donna Paris “EmotionCheck: A Wearable Device DESIGNER JoAnn McHardy to Regulate Anxiety through False Heart SENIOR ADVISORS (Past Editors-in-Chief) Rate Feedback,” by Jean Costa, Alexander Paramvir Bahl, Microsoft Research T. Adams, Malte F. Jung, François Suman Banerjee, University of Wisconsin, Madison Guimbretière, and Tanzeem Choudhury, Srikanth Krishnamurthy, University of California, Riverside describes a device that generates subtle Jason Redi, BBN Technologies vibrations on the wrist to resemble a pulse, Mani Srivastava, University of California, Los Angeles which helps users regulate their anxiety Eyal de Lara Nitin Vaidya, University of Illinois, Urbana-Champaign through false feedback of a slow heart rate. SECTION EDITORS In “HemaApp: Noninvasive Blood Screening of Hemoglobin Ardalan Amiri Sami, University of California, Irvine Using Smartphone Cameras,” Edward Jay Wang, William Li, Doug Aruna Balasubramanian, Stony Brook University Nilanjan Banerjee, University of Maryland, Hawkins, Terry Gernsheimer, Colette Norby-Slycord, and Shwetak N. Baltimore County Patel present a smartphone application that monitors the hemoglobin Geoffrey Challen, University at Buffalo concentration in a patient’s blood by using the smartphone’s RGB Romit Roy Choudhury, University of Illinois, camera and different light sources to illuminate the patient’s fingertip. Urbana-Champaign In “Who are the Smartphone Users? Identifying User Groups Prabal Dutta, University of Michigan Carla S. Ellis, Duke University with Apps Usage Behaviors,” Sha Zhao, Julian Ramos, Jianrong Tao, Michelle X. Gong, Google Ziwen Jiang, Shijian Li, Zhaohui Wu, Gang Pan, and Anind K. Dey Marco Gruteser, Rutgers University report on their efforts using unsupervised learning methods to Haitham Hassanieh, University of Illinois, cluster Android users into distinct types of user groups based on app Urbana-Champaign usage behaviors. They also semantically label each user group with Julie A. Kientz, University of Washington Nic Lane, Bell Labs and University College, London meaningful tags, such as Screen Checkers and Young Parents. Shiwen Mao, Auburn University Lastly, “Interpretable Machine Learning for Mobile Notification Iqbal Mohomed, Samsung Research America Management: An Overview of PrefMiner,” by Abhinav Mehrotra, Sami Rollins, University of San Francisco Robert Hendley, and Mirco Musolesi, describes a notification man- Lin Zhong, Rice University agement solution that automatically learns the types of information Xia Zhou, Dartmouth College that users prefer to receive via notifications in different situations. ACM STAFF The rest of the issue consists of three more columns: Julie Goetz, Administrator – Publications Production Adrienne Griscti, Program Coordinator – SIG Publications The Experimental Methods column features an article by Matthew Fran Spinola, Program Coordinator – SIG Activities Kay, Shwetak N. Patel, and Julie A. Kientz that describes a method SIGMOBILE EXECUTIVE COMMITTEE that developers of mobile sensing applications can use to determine Suman Banerjee, University of Wisconsin-Madison, Chair the degree of accuracy that a new application requires. Lili Qiu, University of Texas Austin, Vice Chair In the Mobile Platforms column, Eduardo Cuervo provides an Marco Gruteser, Rutgers University, Treasurer Alec Wolman, Microsoft Research, Secretary overview of head-mounted display technology and discusses open Cover photo, istockphoto.com istockphoto.com photo, Cover Roy Want, Google, Past Chair research challenges in wireless networking, computation offloading, June 2017 | Volume 21, Issue 2 GetMobile 3 energy management, and security and deploying an always-on connected IoT EDITORIAL CORRESPONDENCE privacy. system for agriculture, which collects data Address to: Prof. Eyal de Lara, 40 St. George Street, Finally, the (Almost) Unpublishable from various sensors, cameras, and drones Suite 4283, Department of Computer Science, University of Toronto, Toronto, Ontario M5S2E4, Results column features an article by Zerina to produce actionable insights for the farmer. Canada, Email: [email protected]. For Kapetanovic, Deepak Vasisht, Jongho Won, I hope you enjoy this issue, and I specific department email addresses, see the Ranveer Chandra, and Mark Kimball that welcome your thoughts about GetMobile “Call for Contributions” on page 59. reports on their experiences developing and in general, and this issue in particular. NOTICE TO CONTRIBUTING AUTHORS TO SIG NEWSLETTERS By submitting your article for distribution in this Special Interest Group publication, you hereby grant to ACM the following non-exclusive, Editorial Board Changes perpetual, worldwide rights: to publish in print Khai N. Truong and Sharad Agarwal are stepping down from the editorial board. As on condition of acceptance by the editor, to founding editors of the Experimental Methods and Mobile Platforms columns, Khai and digitize and post your article in the electronic version of this publication, to include the Sharad have been instrumental to GetMobile’s continued success, and I sincerely thank article in the ACM Digital Library, and to them for the many high-quality columns that they have authored and guided. allow users to copy and distribute the article It is with great pleasure that I extend a warm welcome to the GetMobile editorial for noncommercial, educational or research board to Julie A. Kientz and Ardalan Amiri Sani. Julie is taking over the Experimental purposes. However, as a contributing author, Methods column, while Ardalan joins Marco Gruteser as co-editor of the Mobile you retain copyright to your article and ACM will make every effort to refer requests Platforms column. for commercial use directly to you. ACM GETMOBILE Julie A. Kientz is an Associate Professor in the department of Human ACM SIGMOBILE publishes ACM GetMobile Centered Design & Engineering at the University of Washington. She four times annually for its members. The directs the Computing for Healthy Living and Learning Lab, is active in the Design, Use, Build (DUB) alliance, and has adjunct appointments in Newsletter has a controlled distribution with The Information School and Computer Science & Engineering. Kientz’s the compliments of ACM SIGMOBILE. GetMobile primary research areas are in the fields of human-computer interaction, assumes no responsibility for the return of ubiquitous computing, and health informatics. Her research focuses on submitted manuscripts, photographs, artwork, understanding and reducing the user burdens of interactive technologies or other material. Nothing in this publication for health and education through the design of future applications. Kientz shall constitute an endorsement by ACM, or received her Ph.D. in Computer Science from the Georgia Institute of SIGMOBILE or GetMobile (collectively, the Technology in 2008. She was awarded a National Science Foundation “Publisher”) of any information contained in CAREER Award in 2009, named an MIT Technology Review Innovator this publication, and the Publisher declaims Under 35 in 2013, and she is the recipient of the UW College of any liability with respect thereto or the use or Engineering Faculty Research Innovator award in 2014. reliance on any such information. The infor- mation contained in the publication is in no way to be construed as a recommendation by Ardalan Amiri Sani is an Assistant Professor in the Computer Science the Publisher of any kind or nature whatsoever, Department at the University of California, Irvine. His research interests nor as a recommendation of any industry include mobile computing, operating systems, and system security and standard, nor as an endorsement of any product privacy. He obtained his B.S. from Sharif University of Technology in 2008 and his M.S. and Ph.D. from Rice University in 2011 and 2015, respectively. or service, nor as an opinion or certification Ardalan received the ACM MobiSys Best Paper Award in 2014. regarding the accuracy of any such information. SIGMOBILE URL: http://www.acm.org/sigmobile ISSN 2375-0529 4 GetMobile June 2017 | Volume 21, Issue 2.