Zhihua Lai

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In this article, we propose a new hybrid modeling method for indoor-to-outdoor radio coverage prediction. The proposed method is a combination of a ray-optical channel modeling approach and the frequency domain ParFlow method. While the former is widely used for modeling outdoor propagation environments, the latter is computationally efficient and accurate(More)
This paper investigates the influence of the human body on indoor measurements of radio wave path loss at 3.5 GHz and proposes a solution to improve the accuracy of measurement. The presence of the human body causes measurement errors to radio wave field strength, which is of concern for analysis. The reduction of errors due to measurement process enhances(More)
Propagation modeling has attracted much interest because it plays an important role in wireless network planning and optimization. Deterministic approaches such as ray tracing and ray launching have been investigated, however, due to the running time constraint, these approaches are still not widely used. In previous work, an intelligent ray launching(More)
Three dimension (3D) Multi-input-multi-output (MIMO) scheme, which exploits another dimension of the spatial resource, is one of the enabling technologies for the next generation mobile communication. As the elevation angle in 3D-MIMO channel model might varies against the height of the base station transmit antenna, it has to be taken into account(More)
In this article, we discuss the development of two repositories of shared knowledge using intraand inter-tagging functionality. The functionality enables web user communities to upload, search, navigate through and tag multiple documents in multiple ways at a macro and micro level. Users can tag the whole document as well as parts there-in, as they deem(More)
This article describes the indoor IRLA (Intelligent Ray Launching Algorithm), which originates from an efficient outdoor propagation prediction model. Implementation and validation are given in detail. An indoor office scenario is selected and simulations via the IRLA model and two other reference models have been performed. Predictions are analyzed and(More)
The double parallel-joints CMM is a new coordinate measuring machine that between the tradion coordinate measuring machine and the multi-joint coordinate measuring machine . To further study of the double parallel-joints CMM , it is necessary to study on the error model of the measuring machine. The kinematics model is constructed by the D-H method and the(More)
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