Xidian University

About: Xidian University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Antenna (radio) & Synthetic aperture radar. The organization has 32099 authors who have published 38961 publications receiving 431820 citations. The organization is also known as: University of Electronic Science and Technology at Xi'an & Xīān Diànzǐ Kējì Dàxué.

Dynamic Multiple-Period Reconfiguration of Real-Time Scheduling Based on Timed DES Supervisory Control

Abstract: Based on the supervisory control theory (SCT) of timed discrete-event systems (TDES), this study presents a dynamic reconfiguration technique for real-time scheduling of real-time systems running on uni-processors. A new formalism is developed to assign periodic tasks with multiple-periods. By implementing SCT, a real-time system (RTS) is dynamically reconfigured when its initial safe execution sequence set is empty. During the reconfiguration process, based on the multiple-periods, the supervisor proposes different safe execution sequences. Two real-world examples illustrate that the presented approach provides an increased number of safe execution sequences as compared with the earliest-deadline-first (EDF) scheduling algorithm.

Anonymous attribute-based encryption supporting efficient decryption test

Abstract: Attribute-based encryption (ABE) has been widely studied recently to support fine-grained access control of shared data. Anonymous ABE, which is a relevant notion to ABE, further hides the receivers' attribute information in ciphertexts because many attributes are sensitive and related to the identity of eligible users. However, in existing anonymous ABE work, a user knows whether the attributes and the policy match or not only after repeating decryption attempts. And, the computation overhead of each decryption is high as the computational cost grows with the complexity of the access formula, which usually requires many pairings in most of the existing ABE schemes. As a result, this direct decryption method in anonymous ABE will suffer a severe efficiency drawback.Aiming at tackling the challenge above, we propose a novel technique called match-then-decrypt, in which a matching phase is additionally introduced before the decryption phase. This technique works by computing special components in ciphertexts, which are used to perform the test that if the attribute private key matches the hidden attributes policy in ciphertexts without decryption. In our proposed construction, the computation cost of such a test is much less than one decryption operation. The proposed construction is proven to be secure. In addition, the results in simulation experiments indicate that the proposed solution is efficient and practical, which greatly improves the efficiency of decryption in anonymous ABE.

A Wideband 1 bit 12 × 12 Reconfigurable Beam-Scanning Reflectarray: Design, Fabrication, and Measurement

Abstract: In this letter, a wideband 1 bit 12 × 12 reconfigurable beam-scanning reflectarray is designed, fabricated, and measured. The 1 bit reconfigurable element is realized by soldering PIN diode into a slotted metallic square patch. To enhance the bandwidth of 1 bit reconfigurable reflectarray, we choose the central frequency at 5.0 GHz whose phase shift is 200° where the maximum phase shift occurs. Phase difference within 180° ± 20° is realized from 4.7 to 5.3 GHz. Utilizing this wideband element, the 12 × 12 reconfigurable reflectarray antenna is fabricated and measured. A control board that can display phase shift distributions in real time is designed to regulate all PIN diodes independently. Experimental results show that beam scanning within ±50° can be achieved both in xoz and yoz plane at 5.0 GHz. Also, the measured results present that −1 dB gain bandwidth is 8.4% from 4.85 to 5.275 GHz.

Application of Bionics in Antenna Radar Cross Section Reduction

Abstract: Bionics principle is applied to antenna radar cross section (RCS) reduction in this letter for the first time. To authenticate the method, a novel bionic ultrawideband (UWB) antenna is proposed by use of a model of insect tentacle. Its UWB-related radiation characteristics are simulated and experimentally verified. Monostatic RCS of an insect tentacle antenna (ITA) terminated with three different loads are studied and compared with that of a common printed circular-disc monopole antenna (PCDMA). The results show that compared to the reference antenna, the novel bionic antenna has lower RCS and favorable radiation performances. Hence, applying bionics principle to antenna RCS reduction is feasible, which will serve as a good candidate for the future design of antennas with a requirement of RCS control.

rsfMRI effects of KB220Z™ on Neural Pathways in Reward Circuitry of Abstinent Genotyped Heroin Addicts

Abstract: Recently, Willuhn et al reported that cocaine use and even non-substance-related addictive behavior increases as dopaminergic function is reduced Chronic cocaine exposure has been associated with decreases in D2/D3 receptors and was also associated with lower activation of cues in occipital cortex and cerebellum, in a recent PET study by Volkow's et al Therefore, treatment strategies, like dopamine agonist therapy, that might conserve dopamine function may be an interesting approach to relapse prevention in psychoactive drug and behavioral addictions To this aim, we evaluated the effect of KB220Z™ on reward circuitry of 10 heroin addicts undergoing protracted abstinence (average 169 months) In a randomized placebo-controlled crossover study of KB220Z, five subjects completed a triple-blinded experiment in which the subject, the person administering the treatment, and the person evaluating the response to treatment were blinded to the treatment that any particular subject was receiving In addition, nine subjects were genotyped utilizing the GARSDX™ test We preliminarily report that KB220Z induced an increase in BOLD activation in caudate-accumbens-dopaminergic pathways compared to placebo following 1-hour acute administration Furthermore, KB220Z also reduced resting-state activity in the putamen of abstinent heroin addicts In the second phase of this pilot study of all 10 abstinent heroin-dependent subjects, we observed that three brain regions of interest were significantly activated from resting state by KB220Z compared to placebo (p < 005) Increased functional connectivity was observed in a putative network that included the dorsal anterior cingulate, medial frontal gyrus, nucleus accumbens, posterior cingulate, occipital cortical areas, and cerebellum These results and other quantitative electroencephalogy (qEEG) study results suggest a putative anti-craving/anti-relapse role of KB220Z in addiction by direct or indirect dopaminergic interaction Due to small sample size, we caution definitive interpretation of these preliminary results, and confirmation with additional research and ongoing rodent and human studies of KB220Z is required