by reducing the back-projection in the root process by the relative time of ltering and backprojection, an utilization of 81.8% was achieved. Symmetric Multiprocessor Computations were done on a DEC AlphaServer 2000 4/233. This machine is an SMP with 2 processors , and 256 MB of RAM. The parallel implementation with complete load balancing was used. The serial version ran in 684.2 seconds and t...

The security and eciency of two recently proposed block ciphers, bear and lion, both based on a hash function and a stream cipher, is discussed. Meet-in-the-middle attacks are presented which can be used to dramatically reduce the complexity of a brute-force key search on both these ciphers. A new block cipher is described which is not susceptible to meet-in-the-middle attacks, is provably secu...

This study demonstrates the ecacy of neural implementations of multistage and tree-search quantization. For xed branching ratio we have seen that the tree-search quantizer consistently outperforms the multi-stage structure, though at considerable resource cost. For networks with equal neural resource, the multistage architecture returns signicantly lower mse than the at and tree-search architec...

This paper uses a DEA model of multi-unit eciency measurement to investigate the gains from regional analysis of ecient economic development. The model is applied to the Chinese city economic development data used by Charnes, Cooper, and Li in a recent issue of this journal to demonstrate the usefulness of alternative DEA-based measures in economic development policy. Assuming that Chinese ci...

The conventional de nition of e ciency of a parallel program is based on the assumption that nodes are homogeneous and exclusively available for the tasks of the program. In this paper we present a more general de nition of e ciency, omitting the assumptions of homogeneity and exclusivity. This de nition can be applied to parallel programs e.g. in multi-user environments or to isolated parts of...

In this work, we present a numerical method for solving nonlinear Fredholmand Volterra integral equations of the second kind which is based on the useof Block Pulse functions(BPfs) and collocation method. Numerical examplesshow eciency of the method.

This paper discusses and reviews the use of super-eciency approach in data envelopment analysis (DEA) sensitivity analyses. It is shown that super-eciency score can be decomposed into two data perturbation components of a particular test frontier decision making unit (DMU) and the remaining DMUs. As a result, DEA sensitivity analysis can be done in (1) a general situation where data for a tes...

This paper empirically investigates the x-eciency (technical and allocative) in Australian banks. A non-parametric method of Data Envelopment Analysis (DEA) has been used to arrive at the eciency scores. Banks in this sample were found to have low levels of overall eciency compared with the banks in the European countries and in the US. The results indicate that, as a source of overall inec...

In dynamic object-oriented languages, low-level mechanisms such as just-in-time compilation, object allocation, garbage collection (GC) and method dispatch are o‰en handled by virtual machines (VMs). VMs are typically implemented using static languages, allowing only few changes at run time. In such systems, the VM is not part of the language and interfaces to memory management or method dispat...