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In the field of wireless communications the idea of cognitive radio is of utmost interest. Due to its advantageous propagation properties, the TV white space can be considered to become the first commercial application of cognitive radio. It allows the usage of secondary communication systems at non-occupied frequency bands. Within this paper, spectrum sensing algorithms are introduced for the three predominant Chinese TV standards DTMB, CMMB, and PAL-D/K. A prototype platform is presented and its underlying architecture based on a combination of DSP and FPGA is illustrated including the setup of the cognitive radio application. Furthermore, the performance of the sensing algorithms implemented on the prototype platform is shown in comparison to simulation results.

In this study, the effects of postharvest treatment with 1% pullulan, 2% calcium chloride, and 1% chitosan on the physiological and biochemical properties, enzymatic activities and the differentially expressed genes (DEGs) with sucrose metabolism of Annona squamosa L. fruits stored at 15 ± 1°C for 12 days were investigated. Exogenous substances treatment retained a higher level of firmness, surface color, total soluble solids, organic acids, and tvolatile flavor substances compared to the control fruit. Exogenous substances treatments, particularly calcium chloride, enhanced sucrose phosphate synthase activity, whereas it inhibited acid invertase (AI) and neutral invertase (NI) activities. These changes in enzyme activities together resulted in a significantly higher sucrose content and lower glucose and fructose contents. The number (1550 genes), proportion (6.46%), and expression levels of DEGs in the calcium chloride‐treated fruit, which was enriched in the starch and sucrose metabolism pathways, were all significantly higher than in chitosan treatment. The findings indicated that exogenous calcium chloride might alter sucrose metabolism during fruit ripening by regulating the enzymatic activities and metabolism pathway. This will provide a theoretical basis for further research on the regulation of sugar metabolism by exogenous substances treatment to solve the problem of quality degradation in the storage of A. squamosa. Novelty impact statement: This study indicated that the application of chitosan, pullulan, or calcium chloride, especially calcium chloride treatment, can effectively maintain the quality of Annona squamosa fruit during storage. It was found that exogenous calcium chloride might alter sucrose metabolism during fruit ripening by regulating the enzymatic activities and metabolism pathway. The results provided a theoretical basis for exploring the mechanism of exogenous substances for maintaining the postharvest quality and enhancing the shelf life of A. squamosa fruit in further research. [ABSTRACT FROM AUTHOR]

In the field of wireless communications the idea of cognitive radio is of utmost interest. Due to its advantageous propagation properties, the TV white space can be considered to become the first commercial application of cognitive radio. It allows the usage of secondary communication systems at non-occupied frequency bands. Within this paper, spectrum sensing algorithms are introduced for the three predominant Chinese TV standards DTMB, CMMB, and PAL-D/K. A prototype platform is presented and its underlying architecture based on a combination of DSP and FPGA is illustrated including the setup of the cognitive radio application. Furthermore, the performance of the sensing algorithms implemented on the prototype platform is shown in comparison to simulation results. [ABSTRACT FROM AUTHOR]

The software architecture of Internet of Things defines the component model and interconnection topology of Internet of Things systems. Refactoring is a systematic practice of improving a software structure without altering its external behaviors. When the Internet of Things software is refactored, it is necessary to detect the correctness of Internet of Things software to ensure its security. To this end, this article proposes a novel refactoring correction detection approach to ensure software security. Control flow analysis and data flow analysis are used to detect code changes before and after refactoring, and synchronization dependency analysis is used to detect changes in synchronization dependency. Three detection algorithms are designed to detect refactoring correctness. Four real-world benchmark applications are used to evaluate our approach. The experimental results show that our proposed approach can ensure correctness of Internet of Things software refactoring. [ABSTRACT FROM AUTHOR]

This paper presents a circular disc monopole antenna based on fractal geometry. The antenna is designed to be applied in UWB systems. So it is essential to ensure that the bandwidth of the antenna ranges from 3.1 GHz to 10.6 GHz, that is, IEEE 802.15.3a. However, the proposed antenna has achieved working in the required bandwidth. Compared to the antennas illustrated in most similar literatures, the proposed antenna has a much smaller size, which makes the antenna possible to be integrated with portable devices. Firstly, the antenna was designed through CST Microwave Studio. Then, the antenna was fabricated according to the simulated results. At last, the comparison between the simulated results and measured results was carried out which demonstrated good consistency.