This paper discusses the design, fabrication, and measurement of four L-shaped-slot microstrip patch antenna for HiperLan2. The prototype consists of four L-shaped slots. To obtain suitable bandwidth, the form layer is inserted between the ground plane and substrate. The design considers various important factors that include the four L-slot's length, width, position, air-gap height, and feed-point position. Once these factors are optimized, a four L-shaped slot microstrip patch antenna is fabricated and measured. The measured results of the fabricated four L-shaped slot antenna are as follows: resonant frequency is 5.35 GHz, bandwidth is approximately 8.1% (VSWR < 2.0), and gain is 8-9 dBi. The experimental far-field patterns are stable across the pass band. The 3 dB bandwidth in Elevation and Azimuth are 69and 62, respectively.

We present an adaptive dynamic load balancing scheme for 3D texture based sort-last parallel volume rendering on a PC cluster equipped with GPUs. Our scheme exploits not only task parallelism but also data parallelism during rendering by combining the hierarchical data structures (octree and parallel BSP tree) in order to skip empty regions and distribute proper workloads to rendering nodes. Our scheme can also conduct a valid parallel rendering and image compositing in visibility order by employing a 3D clustering algorithm. To alleviate the imbalance when the transfer function is changed, a load rebalancing is inexpensively supported by exchanging only needed data. A detailed performance analysis is provided and scaling characteristics of our scheme are discussed. These show that our scheme can achieve significant performance gains by increasing parallelism and decreasing synchronizing costs compared to the traditional static distribution schemes.