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

Investigations on electromagnetic noises and interactions in electronic architectures : a tutorial case on a mobile system

Electromagnetic interactions become critic in embedded and smart electronic structures. The increase of electronic performances confined in a finite volume or support for mobile applications defines new electromagnetic environment and compatibility configurations (EMC). With canonical demonstrators developed for tutorials and EMC experiences, this paper present basic principles and experimental techniques to investigate and control these severe interferences. Some issues are reviewed to present actual and future scientific challenges for EMC at electronic circuit level

LSI arrays for space stations

Two approaches have been taken to study CCD's and some of their fundamental limitations. First a numerical analysis approach has been developed to solve the coupled transport and Poisson's equation for a thorough analysis of charge transfer in a CCD structure. The approach is formulated by treating the minority carriers as a surface distribution at the Si-SiO2 interface and setting up coupled difference equations for the charge and the potential. The SOR method is proposed for solving the two dimensional Poisson's equation for the potential. Methods are suggested for handling the discontinuities to improve convergence. Second, CCD shift registers were fabricated with parameters which should allow complete charge transfer independent of the transfer electrode gap width. A test instrument was designed and constructed which can be used to test this, or any similar, three phase CCD shift register

GazeTouchPIN: Protecting Sensitive Data on Mobile Devices Using Secure Multimodal Authentication

Although mobile devices provide access to a plethora of sensitive data, most users still only protect them with PINs or patterns, which are vulnerable to side-channel attacks (e.g., shoulder surfing). How-ever, prior research has shown that privacy-aware users are willing to take further steps to protect their private data. We propose GazeTouchPIN, a novel secure authentication scheme for mobile devices that combines gaze and touch input. Our multimodal approach complicates shoulder-surfing attacks by requiring attackers to ob-serve the screen as well as the user’s eyes to and the password. We evaluate the security and usability of GazeTouchPIN in two user studies (N=30). We found that while GazeTouchPIN requires longer entry times, privacy aware users would use it on-demand when feeling observed or when accessing sensitive data. The results show that successful shoulder surfing attack rate drops from 68% to 10.4%when using GazeTouchPIN

PlaceRaider: Virtual Theft in Physical Spaces with Smartphones

As smartphones become more pervasive, they are increasingly targeted by malware. At the same time, each new generation of smartphone features increasingly powerful onboard sensor suites. A new strain of sensor malware has been developing that leverages these sensors to steal information from the physical environment (e.g., researchers have recently demonstrated how malware can listen for spoken credit card numbers through the microphone, or feel keystroke vibrations using the accelerometer). Yet the possibilities of what malware can see through a camera have been understudied. This paper introduces a novel visual malware called PlaceRaider, which allows remote attackers to engage in remote reconnaissance and what we call virtual theft. Through completely opportunistic use of the camera on the phone and other sensors, PlaceRaider constructs rich, three dimensional models of indoor environments. Remote burglars can thus download the physical space, study the environment carefully, and steal virtual objects from the environment (such as financial documents, information on computer monitors, and personally identifiable information). Through two human subject studies we demonstrate the effectiveness of using mobile devices as powerful surveillance and virtual theft platforms, and we suggest several possible defenses against visual malware