Nowadays energy-efficiency becomes the first design metric in chip development. To pursue higher energy efficiency, the processor architects should reduce or eliminate those unnecessary energy dissipations. Indirect-branch pre- diction has become a performance bottleneck, especially for the applications written in object-oriented languages. Previous hardware-based indirect-branch predictors are generally inefficient, for they either require significant hardware storage or predict indirect-branch targets slowly. In this paper, we propose an energy-efficient indirect-branch prediction technique called TAP (target address pointer) prediction. Its key idea includes two parts: utilizing specific hardware pointers to accelerate the indirect branch prediction flow and reusing the existing processor components to reduce additional hardware costs and power consumption. When fetching an indirect branch, TAP prediction first gets the specific pointers called target address pointers from the conditional branch predictor, and then uses such pointers to generate virtual addresses which index the indirect-branch targets. This technique spends similar time compared to the dedicated storage techniques without requiring additional large amounts of storage. Our evaluation shows that TAP prediction with some representative state-of-the-art branch predictors can improve performance significantly over the baseline processor. Compared with those hardware-based indirect-branch predictors, the TAP-Perceptron scheme achieves performance improvement equivalent to that provided by an 8 K-entry TTC predictor, and also outperforms the VPC predictor. 相似文献
Two conditions must be satisfied in a secure quantum key agreement (QKA) protocol: (1) outside eavesdroppers cannot gain the generated key without introducing any error; (2) the generated key cannot be determined by any non-trivial subset of the participants. That is, a secure QKA protocol can not only prevent the outside attackers from stealing the key, but also resist the attack from inside participants, i.e. some dishonest participants determine the key alone by illegal means. How to resist participant attack is an aporia in the design of QKA protocols, especially the multi-party ones. In this paper we present the first secure multiparty QKA protocol against both outside and participant attacks. Further more, we have proved its security in detail. 相似文献
The computation of a rigid body transformation which optimally aligns a set of measurement points with a surface and related
registration problems are studied from the viewpoint of geometry and optimization. We provide a convergence analysis for widely
used registration algorithms such as ICP, using either closest points (Besl and McKay, 1992) or tangent planes at closest
points (Chen and Medioni, 1991) and for a recently developed approach based on quadratic approximants of the squared distance
function (Pottmann et al., 2004). ICP based on closest points exhibits local linear convergence only. Its counterpart which
minimizes squared distances to the tangent planes at closest points is a Gauss–Newton iteration; it achieves local quadratic
convergence for a zero residual problem and—if enhanced by regularization and step size control—comes close to quadratic convergence
in many realistic scenarios. Quadratically convergent algorithms are based on the approach in (Pottmann et al., 2004). The
theoretical results are supported by a number of experiments; there, we also compare the algorithms with respect to global
convergence behavior, stability and running time. 相似文献
We present a hierarchical test methodology for testing a SOC with heterogeneous cores, including the 1149.1-wrapped, P1500-wrapped, and BIST memory cores. We propose an 1149.1-based hierarchical test manager that also provides P1500 test control signals. This scheme includes a memory BIST interface, providing both serial and parallel access ports for BIST circuits. Our approach offers low area and pin overhead, and high flexibility 相似文献
Multi-view subspace clustering has been an important and powerful tool for partitioning multi-view data, especially multi-view high-dimensional data. Despite great success, most of the existing multi-view subspace clustering methods still suffer from three limitations. First, they often recover the subspace structure in the original space, which can not guarantee the robustness when handling multi-view data with nonlinear structure. Second, these methods mostly regard subspace clustering and affinity matrix learning as two independent steps, which may not well discover the latent relationships among data samples. Third, many of them ignore the different importance of multiple views, whose performance may be badly affected by the low-quality views in multi-view data. To overcome these three limitations, this paper develops a novel subspace clustering method for multi-view data, termed Kernelized Multi-view Subspace Clustering via Auto-weighted Graph Learning (KMSC-AGL). Specifically, the proposed method implicitly maps the multi-view data from linear space into nonlinear space via kernel-induced functions, so as to exploit the nonlinear structure hidden in data. Furthermore, our method aims to enhance the clustering performance by learning a set of view-specific representations and their affinity matrix in a general framework. By integrating the view weighting strategy into this framework, our method can automatically assign the weights to different views, while learning an optimal affinity matrix that is well-adapted to the subsequent spectral clustering. Extensive experiments are conducted on a variety of multi-view data sets, which have demonstrated the superiority of the proposed method.
This study aimed to evaluate the value of using 3-D breast MRI morphologic features to differentiate benign and malignant breast lesions. The 3-D morphological features extracted from breast MRI were used to analyze the malignant likelihood of tumor from ninety-five solid breast masses (44 benign and 51 malignant) of 82 patients. Each mass-like lesion was examined with regards to three categories of morphologic features, including texture-based gray-level co-occurrence matrix (GLCM) feature, shape, and ellipsoid fitting features. For obtaining a robust combination of features from different categories, the biserial correlation coefficient (|rpb|) ≧ 0.4 was used as the feature selection criterion. Receiver operating characteristic (ROC) curve was used to evaluate performance and Student's t-test to verify the classification accuracy. The combination of the selected 3-D morphological features, including conventional compactness, radius, spiculation, surface ratio, volume covering ratio, number of inside angular regions, sum of number of inside and outside angular regions, showed an accuracy of 88.42% (84/95), sensitivity of 88.24% (45/51), and specificity of 88.64% (39/44), respectively. The AZ value was 0.8926 for these seven combined morphological features. In conclusion, 3-D MR morphological features specified by GLCM, tumor shape and ellipsoid fitting were useful for differentiating benign and malignant breast masses. 相似文献