Papers by Author: Hai Guo

Abstract: Nowadays, Wireless sensor networks (WSNs) are appeared to be new and promising solutions for next generation real-time wireless monitoring applications. These WSNs could become a threat if suitable security is not considered before the deployment. However, if there is any loophole in security, that might opens the door to attackers and hence, endanger for the applications. So, user authentication is one of the core requirements to protect WSNs data access from the unauthorized users. In this regard, we propose an efficient two-factor user authentication for WSNs, which is based on password and smart card (two-factors). Our scheme provides mutual authentication, enables the user to choose and change their password frequently. Moreover, they provides strong protection against different kind of attacks at reasonable computation cost.

Abstract: This paper presents a low-power multistage amplifier with a novel Transconductance with Capacitances Feedback Compensation (TCFC) technique. A transconductance stage and two capacitors introduce negative feedback to a three-stage amplifier, which significantly improves the performance such as gain-bandwidth product, slew rate, stability and sensitivity. Implemented in a commercial 0.5-μm CMOS technology and driving 10pF capacitive load, a three-stage TCFC amplifier achieves over 120dB gain, 1.515MHz GBW and 1.3V/μS average slew rate, while only dissipating 380μW under 3.3V supply.

Abstract: Comparing with the phytoplankton, there are few researches on zooplanktons. Now, many waterworks don’t monitor the zooplanktons in source water. There isn’t effective detection method for several common macro zooplanktons such as chironomid larvae, cyclops and so on, and little has been done in the field of the macro zooplanktons automatic identification and monitor. This paper puts for forward a macrozooplankton edge detection method based on wavelet packet decomposition and reconstruction. We erase the high frequency parts by applying wavelet packet decomposition in the original images and then detect the edge of reconstruction images using the common edge detectors such as Prewitt, Sobel, Roberts, Laplacian of Gaussion, Canny and so on. The experimental results show that the edge detection methods in the reconstruction image work better than in the original image.

Abstract: As the only still used pictographs in the world, NaXi pictographs has been used in computer information processing. However, the technology of processing minority scripts hasn't been applied on mobile platform. Using Eclipse, this paper has developed a NaXi Pictographs Mobile Phone Dictionary Based on J2ME. Via Fast Searching Algorithm of Trie tree, we achieved the goal of NaXi-Chinese query and online update of the lexicon. To the problem of display NaXi pictographs on the MT (Mobile Terminal), we extracted matrix font of NaXi pictographs. The realization of NaXi Pictographs Mobile Phone Dictionary drew a new page on the history of information processing on Chinese minority scripts mobile, as well as a great reference for information processing on other minority scripts.