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An improved design of a dual-band circularly polarized (CP) square loop antenna under even-mode resonance is presented in this paper. The designed antenna is fed by a pair of orthogonal dipole launcher with fork-like stubs and connected with a simple balun above the ground plane. Four L-shaped tuning stubs can simultaneously excite the first two, odd-order even-modes. An approximate dual-band ratio design formula is also deduced by using data fitting technique. The proposed antenna exhibits identical CP sensing at its two resonant modes. The proposed approach is expected to get applications in dual-band circularly polarized antenna designs.

Lightning strike and electromagnetic induction resulted from lightning pose a serious threat to the electronic equipment and weapons on the naval ship. Systematic protection design is therefore essential to reduce the probability of electrical equipment and weapons being damaged. In this paper, we discussed the whole ship direct-lightning protection scheme, combining the installation of lightning rods on top of masts as well as the direct lightning strike protection and reinforcement of the local high structures such as ship borne medium-wave and short-wave communication antennas and large radar antennas. The design plans that developing lightning induction protection from different levels such as the platform, system, equipment or subsystem are analysed. The contents and methods of relevant verification and assessment test are also discussed.

A novel multi-beam antenna based on Butler matrix is designed and realized. In this paper, Butler matrix adopts the substrate integrated waveguide and double layer technology to realize the miniaturization of the network, and the two-layer directional coupler achieves good matching and better flatness in amplitude and phase by using multiple slots, besides, the edge gradient short holes of short slot coupler is adopted to better ensure the equipartition of energy, and inhibit the emergence of TE30. The proposed multi-beam antenna has operation frequency range of 8.0 to 8.5GHz with perfect port matching performance. The maximum gain of the intermediate beam of the antenna reaches 11.2dBi, and the maximum gain of the beam on both sides reaches 10.0dBi with ± 38 ° beam point.

A dual-frequency, circularly polarized (CP) square loop antenna under even-mode resonance is presented. The square loop antenna is diagonally fed by a fork-like dipole launcher. Four tuning stubs are symmetrically introduced near the current distribution nulls of the second odd-order resonant even-mode. In this way, the second odd-order even-mode is excited and dual-band circularly polarized characteristic can be realized. The dual-band behavior of the antenna is numerically studied and a closed-form formula is deduced. The preliminary result in this work is expected to be useful in future dual-band CP loop antenna designs.

Because the structure of power system is getting larger and more complex, the configuration of PMU become a more complicated problems. Some algorithms are used to optimize the configuration schemes and achieves anticipated goals, however some of them can not improve the measurement accuracy and increase the computational efficiency at the same time. In order to enhance the precision of state estimation and the efficiency of optimal configuration, this paper models genetic algorithm into the MapReduce model, so the MapReduce genetic algorithm(MRGA) possesses some parallel computing performance, such as scalability, better fitness convergence and so on. MRGA is implemented on computing clusters of Hadoop to search the optimal configuration of PMU. Meanwhile, this feasibility and the computing performance of MRGA is verified by IEEE14-node system, IEEE118-node system, and Wp2383-node system. This method has significant advantages in the installed PMU number, the diversity of solution, the astringency and the practicability.

In the era of open innovation, external knowledge acquisition and exploitation have been a strategic choice for improving the innovation of firms. Existing literatures have discovered a complicated relationship between external knowledge acquisition and a firm's innovation but it has failed to explain the mechanism behind this relationship. This study, based on the perspective that external knowledge needs to be internalized by internal firm practices, explores the effect of information communication and innovation incentives on the transformation from an external knowledge acquisition to firm innovation. Hierarchical regression is used to investigate this question through 489 large and medium-sized companies in China and the results show that the positive impact of external knowledge acquisition on firm innovation is partially mediated by within-firm communication and an innovation incentive policy.

This paper researches and designs an information interaction interface, which exchanges information between electrical home appliances and smart grid, thus accomplishes the function of data acquisition and appliance control. With regard to the designed logical functional structure of external and internal grid information interaction interface, procedure of information interaction, interaction scheme and communication protocol during interaction process is analysed in detail. The procedure of interactional service between electrical home appliances and smart grid is illustrated by describing coordinating operation of grid information interaction interface's functional modules, by which the goal of power demand response, energy management and power load control is achieved finally.

An adhesive structure specimen, fabricated with several back-drilled flat holes of different size to simulate debond defects, was inspected by infrared thermography. Three larger defects could be seen directly by the raw images. However, two smaller defects could not be detected by the raw images because of high noise. The noise contributed by the variation of surface emissivity, was eliminated to some extent by coating the testing surface with uniform emissivity black paint in the experiment. It is found that the surface temperature changes with time satisfying exponential form. Therefore, a robust reducing noise method — exponential fitting of every pixel as a function of time, was presented to eliminate unwanted temporal noise in the raw images. Spatial noise was reduced by the combination some standard filtering algorithms e.g. average filtering with high-pass filtering, which made the invisible defect be detected. Finally, image segmentation algorithms based on watershed and 3D tomogram were used to visualize the defects, and defect's parameters were also estimated by the image after segmentation. The results show that the methods used in this work could improve defect detectability and achieve defect quantitative identification.

In the paper, the status of flood disaster in China and the progress of disaster prevention and reduction in the field of property insurance were analyzed. The characteristics and application fields of 3S (GIS, RS and GPS) were also introduced. According to the current need and future development of property insurance company, which were based on the investigation to the work of disaster prevention and reduction in property insurance and casualty company (abbreviated as PICC) China, the authors decided to apply 3S technologies to the field of property insurance and used the successful methods in foreign property insurance companies for reference to develop a decision support system of flood disaster for property insurance. The system linked well with the operational system of insurance company and realized seamless integration between different data sources. The work of disaster prevention and reduction in property insurance company was better organized both in theory ways and in key technologies. As a result, the economic benefit of property insurance company was really improved. The system was applied in Shenzhen, China and the result was satisfying

Normalized difference vegetation index (NDVI) plays an important role in the detection of drought and desertification. However, being calculated by direction limited spectral reflectance, it is almost ignorant to anisotropy of target reflection. In this paper, on the basis of atmospheric correction of Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data using 6S (Second Simulation of Satellite Signal in the Solar Spectrum) code, bidirectional reflectance distribution function (BRDF) of surface coverage is obtained to retrieve spectral albedos of certain wavelengths. Narrowband spectral albedo to broadband albedo conversion is accomplished via measured band data and simulation of unknown spectral wavelengths which are not available by Landsat-7 ETM+ imagery. Albedo based ecological safety monitoring index (ESMI) is developed and sensitivity analysis of ESMI in surface application is conducted. Application results show that ESMI has potential use in quantitative monitoring of eco-environmental problems