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This paper presents our research on secure and accurate targeted mobile coupon delivery. Our goal is to enable the secure delivery of targeted coupons to eligible users equipped with mobile devices, whose behavioral profiles accurately satisfy the targeting profile defined by the vendor. Our design well preserves user privacy, and further provides the strict security guarantee of vendor protection, by verifying user’s eligibility for a coupon without revealing the vendor’s targeting profile. We first show a basic approach which can effectively address the challenges posed by secure and accurate targeted coupon delivery, via properly leveraging Yao’s garbled circuits. In order to achieve practical performance for resource-limited mobile devices, we then present our proposed design, which imposes lightweight workload on the user side, via properly bridging together homomorphic encryption and Yao’s garbled circuits. We implement a preliminary user-side prototype and deploy it on an Android smartphone to evaluate the performance. Extensive experimental results demonstrate that our proposed design achieves practical performance for mobile devices.

Mobile advertising has become a key economic force with the growing mobile app markets. Targeted advertising has been attracting the attention of business and research communities because of its high return on investment. However, the fact that it requires continuous collection of user profiles raises severe privacy concerns. In this paper, we propose a secure and practical mobile advertising architecture, which aims to enable targeted advertising over encrypted mobile user profiles. The proposed idea is based upon a cryptographic primitive, i.e., private stream searching (PSS). We first propose a basic construction of secure targeted mobile advertising. Thorough analysis shows that our basic design achieves semantic security. After that, we introduce a number of techniques to make our design more efficient for mobile devices. Experimental results demonstrate the practicality of our proposed architecture.

Mobility models play a crucial role in mobility wireless networks with respect to evaluating the network protocols and performances. However, the majority of existing mobility models either does not exhibit realistic movement characteristics or modeling methods are too complex. In this paper, a new mobility model based on Location Attraction (LAMM) is proposed, which utilizes human's clustering features in real life. Through analyzing real GPS trace of mobile users, we observe the number and location attraction of hot regions. We find that the number of hot regions is extremely stationary in an observation area, and the pause position density within hot regions show a trend with exponential decline. Based on such movement characteristics, we developed a mobility model and the validation shows that LAMM better depict the mobility patterns of human.

Composites of polyaniline (PANI) and multi-wall carbon nanotubes (MWNT) were synthesized by in-situ polymerization at different multi-wall carbon nanotube contents. The composites were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and X-ray power diffraction (XRD). The results show that a mass of MWNT was enchased into PANI matrix and a bit of MWNT's surface was covered with PANI. There are no covalent interactions between PANI and MWNT. The composites' conductibility was measured by four-point electric conductivity measurement on pellets compressed at 20MPa. It can be confirmed that the composites of carbon nanotubes have a higher conductivity compared to pure PANI. The composites did not have a lower infrared emissivity than pure PANI and the magnitude of infrared emissivity was not influenced by the content of MWNT within the percentage range of MWNT studied.

Ni-doped ZnO(ZnO:Ni)thin film had been studied widely as a ferromagnetic semiconductor, but there are far fewer studies on its infrared characteristics. This paper describes experiments in which Ni-doped ZnO thin films were deposited on quartz glass using a sol-gel process with different sintering temperatures. The infrared characteristics and the effects of the different fabrication processes were investigated using various techniques including X-ray diffraction (XRD), SEM and FT-IR.