33,913 research outputs found
Characterizing Power Consumption of Dual-Frequency GNSS of a Smartphone
Location service is one of the most widely used features on a smartphone.
More and more apps are built based on location services. As such, demand for
accurate positioning is ever higher. Mobile brand Xiaomi has introduced Mi 8,
the world's first smartphone equipped with a dual-frequency GNSS chipset which
is claimed to provide up to decimeter-level positioning accuracy. Such
unprecedentedly high location accuracy brought excitement to industry and
academia for navigation research and development of emerging apps. On the other
hand, there is a significant knowledge gap on the energy efficiency of
smartphones equipped with a dual-frequency GNSS chipset. In this paper, we
bridge this knowledge gap by performing an empirical study on power consumption
of a dual-frequency GNSS phone. To the best our knowledge, this is the first
experimental study that characterizes the power consumption of a smartphone
equipped with a dual-frequency GNSS chipset and compares the energy efficiency
with a single-frequency GNSS phone. We demonstrate that a smartphone with a
dual-frequency GNSS chipset consumes 37% more power on average outdoors, and
28% more power indoors, in comparison with a singe-frequency GNSS phone.Comment: Published in IEEE Global Communications Conference (GLOBECOM
Secure Pick Up: Implicit Authentication When You Start Using the Smartphone
We propose Secure Pick Up (SPU), a convenient, lightweight, in-device,
non-intrusive and automatic-learning system for smartphone user authentication.
Operating in the background, our system implicitly observes users' phone
pick-up movements, the way they bend their arms when they pick up a smartphone
to interact with the device, to authenticate the users.
Our SPU outperforms the state-of-the-art implicit authentication mechanisms
in three main aspects: 1) SPU automatically learns the user's behavioral
pattern without requiring a large amount of training data (especially those of
other users) as previous methods did, making it more deployable. Towards this
end, we propose a weighted multi-dimensional Dynamic Time Warping (DTW)
algorithm to effectively quantify similarities between users' pick-up
movements; 2) SPU does not rely on a remote server for providing further
computational power, making SPU efficient and usable even without network
access; and 3) our system can adaptively update a user's authentication model
to accommodate user's behavioral drift over time with negligible overhead.
Through extensive experiments on real world datasets, we demonstrate that SPU
can achieve authentication accuracy up to 96.3% with a very low latency of 2.4
milliseconds. It reduces the number of times a user has to do explicit
authentication by 32.9%, while effectively defending against various attacks.Comment: Published on ACM Symposium on Access Control Models and Technologies
(SACMAT) 201
Thermal analysis of lithium ion battery-equipped smartphone explosions
Thermal management of mobile electronics has been carried out because performance of the application processor has increased and power dissipation in miniaturized devices is proportional to its functionalities. There have been various studies on thermal analyses related to mobile electronics with the objectives of improving analysis methodologies and cooling strategies to guarantee device safety. Despite these efforts, failure to control thermal energy, especially in smartphones, has resulted in explosions, because thermal behaviors in the device under various operating conditions have not been sufficiently conducted. Therefore, several scenarios that caused the failure in thermal management of smartphone was analyzed to provide improved insight into thermal design deducing the parameters, that affect the thermal management of device. Overcurrent in battery due to malfunction of battery management system or immoderate addition of functionalities to the application processor are considered as reliable causes leading to the recent thermal runaways and explosions. From the analyses, it was also confirmed that the heat generation of the battery, which have not been considered importantly in previous literature, has significant effect on thermal management, and heat spreading could be suppressed according to arrangement of AP and battery. The heat pipe, which is utilized as a cooling device in mobile electronics, was also included in the thermal analyses. Although the heat pipes have been expected to improve the thermal management in mobile electronics, it showed limited heat transfer capacity due to its operating conditions and miniaturization. The demonstrated results of our analysis warn against vulnerabilities of smartphones in terms of safety in design
MOSDEN: A Scalable Mobile Collaborative Platform for Opportunistic Sensing Applications
Mobile smartphones along with embedded sensors have become an efficient
enabler for various mobile applications including opportunistic sensing. The
hi-tech advances in smartphones are opening up a world of possibilities. This
paper proposes a mobile collaborative platform called MOSDEN that enables and
supports opportunistic sensing at run time. MOSDEN captures and shares sensor
data across multiple apps, smartphones and users. MOSDEN supports the emerging
trend of separating sensors from application-specific processing, storing and
sharing. MOSDEN promotes reuse and re-purposing of sensor data hence reducing
the efforts in developing novel opportunistic sensing applications. MOSDEN has
been implemented on Android-based smartphones and tablets. Experimental
evaluations validate the scalability and energy efficiency of MOSDEN and its
suitability towards real world applications. The results of evaluation and
lessons learned are presented and discussed in this paper.Comment: Accepted to be published in Transactions on Collaborative Computing,
2014. arXiv admin note: substantial text overlap with arXiv:1310.405
SaferCross: Enhancing Pedestrian Safety Using Embedded Sensors of Smartphone
The number of pedestrian accidents continues to keep climbing. Distraction
from smartphone is one of the biggest causes for pedestrian fatalities. In this
paper, we develop SaferCross, a mobile system based on the embedded sensors of
smartphone to improve pedestrian safety by preventing distraction from
smartphone. SaferCross adopts a holistic approach by identifying and developing
essential system components that are missing in existing systems and
integrating the system components into a "fully-functioning" mobile system for
pedestrian safety. Specifically, we create algorithms for improving the
accuracy and energy efficiency of pedestrian positioning, effectiveness of
phone activity detection, and real-time risk assessment. We demonstrate that
SaferCross, through systematic integration of the developed algorithms,
performs situation awareness effectively and provides a timely warning to the
pedestrian based on the information obtained from smartphone sensors and Direct
Wi-Fi-based peer-to-peer communication with approaching cars. Extensive
experiments are conducted in a department parking lot for both component-level
and integrated testing. The results demonstrate that the energy efficiency and
positioning accuracy of SaferCross are improved by 52% and 72% on average
compared with existing solutions with missing support for positioning accuracy
and energy efficiency, and the phone-viewing event detection accuracy is over
90%. The integrated test results show that SaferCross alerts the pedestrian
timely with an average error of 1.6sec in comparison with the ground truth
data, which can be easily compensated by configuring the system to fire an
alert message a couple of seconds early.Comment: Published in IEEE Access, 202
- …