Cooperative Friendly Jamming Techniques for Drone-Based Mobile Secure Zone.

Threats of eavesdropping and information leakages have increased sharply owing to advancements in wireless communication technology. In particular, the Internet of Things (IoT) has become vulnerable to sniffing or jamming attacks because broadcast communication is usually conducted in open-network environments. Although improved security protocols have been proposed to overcome the limitations of wireless-communication technology and to secure safe communication channels, they are difficult to apply to mobile communication networks and IoT because complex hardware is required. Hence, a novel security model with a lighter weight and greater mobility is needed. In this paper, we propose a security model applying cooperative friendly jamming using artificial noise and drone mobility, which are autonomous moving objects, and we demonstrate the prevention of eavesdropping and improved security through simulations and field tests. The Cooperative Friendly Jamming Techniques for Drone-based Mobile Secure Zone (CFJ-DMZ) can set a secure zone in a target area to support a safe wireless mobile communication network through friendly jamming, which can effectively reduce eavesdropping threats. According to the experimental results, the average information leakage rate of the eavesdroppers in CFJ-DMZ-applied scenarios was less than or equal to 3%, an average improvement of 92% over conventional methods.

Remarkable mobility increase and threshold voltage reduction in organic field-effect transistors by overlaying discontinuous nano-patches of charge-transfer doping layer on top of semiconducting film.

An effective strategy for significantly increasing the organic transistor mobility with simultaneous reduction of the threshold voltage utilizing discontinuous nano-patches of charge-transfer doping layer is demonstrated. By overlaying the nano-patches on top of a given semiconducting film, mobility and threshold voltage of p-type pentacene are remarkably improved to 4.52 cm(2) V(-1) s(-1) and -0.4 V, and those of n-type Hex-4-TFPTA are also improved to 2.57 cm(2) V(-1) s(-1) and 4.1 V.

High-performance n-type organic semiconductors: incorporating specific electron-withdrawing motifs to achieve tight molecular stacking and optimized energy levels.

Novel π­conjugated cyanostilbene-based semiconductors (Hex-3,5-TFPTA and Hex-4-TFPTA) with tight molecular stacking and optimized energy levels are synthesized. Hex-4-TFPTA exhibits high-performance n-type organic field-effect transistor (OFET) properties with electron mobilities as high as 2.14 cm2 V−1s−1 and on-off current ratios