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The clustered loop buffer VLIW processor has been developed to enhance the performance of multimedia applications in which loop intensive codes are used. In this paper, we employ a dynamic branch predictor in the clustered loop buffer VLIW architecture to handle branch instructions in loop-rich codes, such as multimedia applications, via dynamic speculation. To reduce the energy consumption we map two power reduction techniques, which are hint instruction method and pipeline gating method, on the architecture and analyze their performances using MediaBench applications. In our experiment, we observed that the hint instruction method helps reducing the dynamic branch predictor usage for all the applications tested, by at least 70%. The pipeline gating method was observed to be beneficial to only a subset of the applications with up to 20% of savings.

This paper presents an efficient parallel-and-distributed string matching scheme in a heterogeneous environment. The contribution of the proposed approach is in two-fold; exploiting a non-trivial parallelism in each node that possibly is SMP, and distributed processing with dynamic load balancing on a network-connected system. For the parallel processing in each node, a multithreaded computation model is designed and implemented with Java Threads. For the distributed processing, a dynamic load balancing method is developed and implemented with Java RMI. The proposed approach manipulates both exact string matching and approximate string matching with k-mismatches. Experimental results demonstrate that the approach is an efficient parallel-and-distributed solution to the problem in a clustered system that is either homogeneous or heterogeneous.

This paper investigates the aliasing problems in global-history-based and local-history-based branch predictors and presents two approaches to improve the performance of global-history-based branch predictors. Global-history-based predictors have more critical aliasing problems but show the better performance than local-history-based predictors. Therefore, our approaches mainly focus on alleviating the aliasing problems for global-history-based predictors. The performance of each approach is evaluated and compared by using the Simplescalar simulator with SPEC95CINT benchmark programs. Our experimental results show that the approaches outperform conventional global-history-based branch predictors.

Being aware of growing needs for wireless communication led to the development of UWB systems, this study proposed an impulse for single band UWB systems which does not count a carrier; analyzed the characteristics and the problems of pulses suggested by the existing pulse of the UWB system; finally, proposed TDMG (time delay multiple Gaussian) pulse that generates signals of UWB without attenuation of pulse width. The hardware structure of the TDMG pulse for the single band UWB system was modeled after describing the pulse in a mathematical method in an attempt to compare with performances of the existing pulses through computer simulation. The outcome of the test unveiled the fact that each center frequency of the TDMG pulse rose approximately 1 GHz, and also each 10 dB fractional bandwidth of the TDMG pulse was widened over 1 GHz. In the case of derivative, center frequencies of the TDMG pulse rose over 1 GHz each. As a consequence, the TDMG pulse appeared to have better quality frequency, satisfying the characteristics of spectrum and the band of frequency recommended by the FCC and decreasing interference with other wireless communication systems.

IPv6 defines relation between surrounding node using Neighbor Discovery protocol. Used Neighbor Discovery messages, grasp surrounding node, included important information about network. These network Information outcrops can give rise in network attack and also service that use network will paralysis. Various kinds of security limitation were found in Present Neighbor Discovery protocol therefore security function to supplement this problem was required. In this thesis, Secure Neighbor Discovery protocol, add with security function, was designed and embodied by CGA module and SEND module.