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241.
Hold timing closure is an important milestone at the physical design phase of every Application Specific Integrated Circuit (ASIC). Many approaches have been proposed by different researchers and commercial Electronic Design Automation (EDA) providers to fix hold timing violations, but there has been no effort to study the impact of each technique on power consumption. Nowadays, the rise of low power applications demand keeps pushing for the invention of new power reduction techniques. In this paper, we presented a novel approach for power consumption reduction by reducing the power increase seen during the hold timing optimization. A sample of 100 industrial post-CTS designs from different applications and fabrication process technologies (from 180 nm to 28 nm) was used to measure the ratios of Δpower/Δhold_timing and Δarea/Δhold_timing of each technique. The ratios were calculated after legalization and global routing to include not only the power/area added directly by the hold optimization, but also the power/area increases induced indirectly by the additional timing fixes needed after placement legalization and routing repair. By considering the impact on power consumption and area increase of each technique while optimizing the design we have reduced substantially the power increase and the area overhead caused by the hold fixing. Experimental results show a power reduction of 7%, and an area reduction of 1% on average, with a beneficial impact on hold timing and a neutral impact on setup timing. 相似文献
242.
《复变函数与椭圆型方程》2012,57(6):521-535
In this paper new solutions of the Bauer-Peschl equation represented by differential operators are derived. A relation to the solutions of Bauer is given. Furthermore, it will be said in which new way Bauer's solutions can be obtained. Also three other ways for obtaining the solutions of the Bauer-Peschl equation are sketched. 相似文献
243.
A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users. 相似文献
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The development of inviscid and viscous flow solvers for both structured and unstructured meshes is presented in this paper. The solution method is the distribution-formula scheme. This is an explicit, cell-vertex, finite volume method which is essentially second-order accurate in both space and time. The Euler and Navier-Stokes equations are integrated over each finite volume cell to determine the change in flow properties (e.g. density) for the cell. Distribution formulas are then used to distribute such changes to the surrounding vertices. Increments in each vertex (which is a calculation point) thus consist of contributions from the surrounding cells. The original discretization technique involves central differencing and is simple, robust and computationally efficient. In this work, starting with inviscid flow simulations using the original scheme on structured grids, improvements are subsequently made to the scheme by replacing the central differencing portion with MUSCL type higher-order upwind differencing. Numerical investigations with the improved scheme are performed using inviscid flow simulations on structured grids. Upon establishing improved accuracy, stability and excellent shock capturing properties, further extension to viscous flow computations on unstructured adaptive meshes is implemented. Results are presented for laminar, viscous flow over a NACA 0012 airfoil. 相似文献
246.
Faker Ben Belgacem & Sidi-Mahmoud Kaber 《数学研究》2015,48(4):330-344
Observability Gramians of diffusion equations have been recently connected
to infinite Pick and Cauchy matrices. In fact, inverse or observability inequalities can
be obtained after estimating the extreme eigenvalues of these structured matrices,with
respect to the diffusion semi-group matrix. The purpose is hence to conduct a spectral
study of a subclass of symmetric Cauchy matrices and present an algebraic way to
show the desired observability results. We revisit observability inequalities for three
different observation problems of the diffusion equation and show how they can be
(re)stated through simple proofs. 相似文献
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R. T. Pardasani P. Pardasani C. K. Ojha D. Sherry V. Chaturvedi I. Sharma 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2435-2443
The condensation of 1,2- and 1,4-diketones with thiohydantoins to give tetrahydroquinodimethane and isatylidene derivatives respectively is described which may act as potential precursors for indigoid dyes as well as bioactive compounds. The synthesized compounds have been characterized by elemental analyses, spectral studies as well as by molecular modelling using PC WIN model. In addition, the newly synthesized products have been screened for antimicrobial activity. 相似文献