Showing papers by "Katarzyna Wac published in 2012"

Factors influencing quality of experience of commonly used mobile applications

Abstract: Increasingly, we use mobile applications and services in our daily life activities, to support our needs for information, communication or leisure. However, user acceptance of a mobile application depends on at least two conditions: the application's perceived experience, and the appropriateness of the application to the user's context and needs. However, we have a weak understanding of a mobile user's quality of experience (QoE) and the factors influencing it. This article presents a 4-week-long 29-Androidphone- user study, where we collected both QoE and the underlying network's quality of service measurements through a combination of user, application, and network data on the user's phones. We aimed to derive and improve the understanding of users' QoE for a set of widely used mobile applications in users' natural environments and different daily contexts. We present data acquired in the study and discuss implications for mobile applications design.

Smartphone as a Personal, Pervasive Health Informatics Services Platform: Literature Review

Abstract: Smartphone as a Personal, Pervasive Health Informatics Services Platform: Literature Review -

Mobile psychiatry: towards improving the care for bipolar disorder

Abstract: Background Mental health has long been a neglected problem in global healthcare. The social and economic impacts of conditions affecting the mind are still underestimated. However, in recent years it is becoming more apparent that mental disorders are a growing global concern and there is a necessity of developing novel services and researching effective means of providing interventions to sufferers. Such novel services could include technology-based solutions already used in other healthcare applications but are yet to make their way into standard psychiatric practice.

On the ambiguity of Quality of Service and Quality of Experience requirements for eHealth services

Abstract: The use of end-to-end communication systems as a medium of delivery for electronic healthcare (eHealth) services is considered to be uncertain, with respect to its reliability leading to hesitation in acceptance of such services. There exist different influential dimensions that pose stringent requirements on end-to-end communication systems, influence user perception and might hinder user acceptance. The later is referred to as Quality of Experience (QoE), which among others depends on the Quality of Service (QoS) of the end-to-end communication system. QoE is considered as a key component determining user acceptance. This paper identifies and analyzes characteristics of a set of eHealth services and the influential dimensions resulting in different QoS requirements and potential impact of QoS on QoE. It highlights the role of QoS and QoE for acceptance of these services. The issue of non-uniform views regarding QoS parameter specifications and related requirements, clinically acceptable thresholds and their qualitative representation in eHealth literature is reviewed and presented.

Studying the challenges in assessing the perceived quality of mobile-phone based video

Abstract: Evaluating video Quality of Experience (QoE) on a mobile phone has not yet been studied much. It is common that the data collected through user studies in mobile platform involves high fluctuation of user ratings without obvious reasons related to variation in network level. User disparity, user's various intermediate or previous experiences, video bitrate, and the objective measure of criticality are a few of the reasons that need to be identified with a well-designed user experiment. We present an experiment procedure to understand better the perceived quality of video in mobile platform. First, we investigate the reliability of the data, and identify unreliable users. Then, we investigate the psychological influence factors of previous experiences on the recent perceived quality known as the memory effect, and the influence of the bitrate on the time it takes for users to react and evaluate the video quality, i.e., user response time.

Demonstrating the stalling events with instantaneous total power consumption in smartphone-based live video streaming

Abstract: The smartphone usage nearly tripled in 2011 according to Cisco Virtual Networking Index. There is a high demand of energy for using popular mobile applications, which run on smartphones with limited battery life. Video streaming applications are widely used on mobile devices, and their high power consumption exhibits high variance during a live streaming session, due to varying conditions on network and application levels. Recent studies focus on the averaged power consumption statistics, while there is lack of observation on the fluctuations of the instantaneous total power consumption of the smartphones. Network based applications consume power at all layers of the communication stack, and any fluctuation in the total power consumption during a video streaming can reveal a possible misbehaviour such as a stalling event. Until now, these events are investigated in Quality of Experience (QoE) studies through installation of high-energy demanding and hard-to-deploy network measurement tools on users' mobile devices. In this paper, we demonstrate an experiment, where a user experiences a stalling event on the smartphone and observes the live instantaneous power consumption values through Mobile Power Monitoring Tool (MPMT) and Software Visualisation Tool (SVT), simultaneously. We confer that the instantaneous total power consumption likely reveals the misbehaviours such as stalls during a video playout in live video streaming on smartphones that can facilitate energy efficient QoE studies.

Ubiquitous inference of mobility state of human custodian in people-centric context sensing

Abstract: People-centric sensing using people's smartphones offers new research opportunities for large case studies. It presents many challenges, e.g., efficient capture of person's mobility, understanding of context changes and preservation of user privacy. We propose an accurate and energy-efficient method able to capture user's mobility, thus the context changes, while preserving his/her privacy. Our solution can be applied to systems that aim to efficiently sense context on smartphones to study large scale phenomena or perform location management.

Deriving Connectivity and Application Usage Patterns From Longitudinal Mobile Phone Usage Data

Abstract: In this paper, based on the Mobile Data Challenge data obtained from the Lausanne data collection campaign, our research aims first to derive network connectivity (e.g., WLAN, 3G) and its Quality of Service (QoS) and mobility patterns of the mobile users, as this connectivity and QoS relate to the user's application activity. Second, we aim to understand how these patterns relate to the overall Quality of Experience (QoE) of the user. Concerning the mobility patterns, we define indoor and outdoor activity for each mobile user. Moreover, we attempt to define semantic places using time filters and GIS techniques, which could also be correlated to the application activity of the users. By correlating the above with the application activity of the users, as well as the hour and weekday patterns, certain inferences can be extracted, concerning the users' spatial and temporal behaviour. These inferences could be used further in developing methods for assurance of the mobile users' QoE.

Estimating People Perception of Intimacy in Daily Life from Context Data Collected with Their Mobile Phone

Abstract: Nowadays, personal context is extensively used in personalized mobile services. However, gathering this kind of information may compromise the privacy of the user. Moreover, the number of services that collect and share the personal context with others is growing. Yet, the users are not able to easily control what information is shared and with whom. An important step towards this goal is to understand how and when the user wants to share his personal context. The literature suggests that the willingness to disclose personal information depends on the level of intimacy perceived in given contexts. In this paper we show how the MDC data enabled us to estimate the level of intimacy of the user in a given contexts of his/her daily life.

Future Internet for eHealth (Dagstuhl Seminar 12231)

Abstract: From June 3-6, 2012, the Dagstuhl Seminar ``Future Internet for eHealth'' was held in Schloss Dagstuhl-Leibniz Center for Informatics. During this seminar, participants presented their current research, and ongoing work and open problems were discussed. The executive summary and abstracts of the talks given during the seminar are put together in this paper.

Phone in the Pocket: Pervasive Self-Tracking of Physical Activity Levels

Abstract: Mobile (smart) phones prevail in our daily life activities, and in our research we aim for it to provide pervasive services for wellness. Therefore, we assess the phone’s feasibility to unobtrusively, continuously and in real-time track its user’s physical activity and the resulting energy expenditure (EE). Activity Level Estimator (ALE) is an Android OS application developed for that purpose.We have assessed the accuracy of ALE against the BodyMedia SenseWear (SW) device and the gold standard for EE estimation, i.e., an indirect calorimetry (IC) method. ALE has mean accuracy of 86% (vs. SW) to 93% (vs. IC) for walking, and in 24h it underestimates EE by 23% ALE is currently used for a long-term behavioral trends study with the University of Geneva students and faculty.