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1.
Ramanujam J. Jinpyo Hong Kandemir M. Narayan A. Agarwal A. 《Signal Processing, IEEE Transactions on》2006,54(1):286-294
Most embedded systems have limited amount of memory. In contrast, the memory requirements of the digital signal processing (DSP) and video processing codes (in nested loops, in particular) running on embedded systems is significant. This paper addresses the problem of estimating and reducing the amount of memory needed for transfers of data in embedded systems. First, the problem of estimating the region associated with a statement or the set of elements referenced by a statement during the execution of nested loops is analyzed. For a fixed execution ordering, a quantitative analysis of the number of elements referenced is presented; exact expressions for uniformly generated references and a close upper and lower bound for nonuniformly generated references are derived. Second, in addition to presenting an algorithm that computes the total memory required, this paper also discusses the effect of transformations (that change the execution ordering) on the lifetimes of array variables, i.e., the time between the first and last accesses to a given array location. The term maximum window size is introduced, and quantitative expressions are derived to compute the maximum window size. A detailed analysis of the effect of unimodular transformations on data locality, including the calculation of the maximum window size, is presented. 相似文献
2.
Marginal costs of electricity vary by time and location. In the past, researchers attributed the variations to factors related to electricity generation and transmission. These authors, however, have not analyzed possible variations in marginal distribution capacity costs (MDCC). The objectives of this paper are:
- 1. (i) to show that large MDCC variations are due to the dispersion in distribution capital expenditures by time and space,
- 2. (ii) to propose a method for quantifying the area- and time-specific MDCC in the presence of lumpy investments, and
- 3. (iii) to compare our MDCC estimates to those commonly used in the electric utility industry.
3.
4.
5.
6.
Petr A. Nikrityuk Kerstin Eckert Roger Grundmann 《Metallurgical and Materials Transactions B》2006,37(3):349-359
This paper presents a numerical study of the Lorentz force and fluid flow induced by a rotating magnetic field in a medium
with a nonhomogeneous electric conductivity placed in a cylindrical vessel with insulated walls. The nonhomogeneity is modeled
by the presence of a solid and a liquid phase of different electrical conductivity. The solid phase is located orthogonally
to the axis of rotation, which corresponds to the case of unidirectional solidification. The simulations were performed for
different locations of the solid front and different ratios of the electrical conductivity, σ
s
/σ
l
=0.2... 10. Here σ
s
and σ
l
are the electric conductivity of the solid and liquid phases, respectively. The results showed that the difference between
electrical conductivity of solid and liquid phases has a noticeable effect on the mean-time Lorentz force and the velocity:
namely, the presence of the solid phase (σ
s
>σ
l
) leads to an increase of the Lorentz force and fluid flow in the cylinder. 相似文献
7.
Roger L. Kemp 《Cities》1985,2(3):252-255
Since the early 1970s, local governments in the USA have faced limited tax income combined with double-digit inflation. As a result, every local service from fire prevention to recreation has had to be closely scrutinized. Local administrators and politicians have evolved new and innovative retrenchment management policies to respond to both the demands of citizens and the fewer dollars available. A combination of denial of new programmes and public sector pay austerity, with public education and use of community organizations is providing ways to stretch limited funds. The reality in many communities across the USA is that local government and its services will not be growing in the future. 相似文献
8.
Develops 3 hypotheses to explain the role of construal processes in conformity behavior. According to the preconformity change of meaning hypothesis, social influence leads to changes in situational construal that precede and mediate conformity behavior; according to the postconformity change of meaning hypothesis, construal change follows and justifies conformity; and according to the construal-consistency hypothesis, preexisting situational construal distinguishes those who conform from those who dissent. Four experimental studies with varying methodology and involving a total of 361 undergraduate students were performed to test these hypotheses. The results of all studies provide strong evidence for postconformity change of meaning effects. Discussion centers on possible domains in which the different construal mechanisms might operate. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
Sabha Kesraoui-Ouki Christopher R. Cheeseman Roger Perry 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,59(2):121-126
This paper assesses the potential of natural zeolite utilization as a low-cost ion-exchange and sorbent material in pollution control and recovery of metals. The improvement of the purity of natural zeolites coupled with their chemical modification capabilities in order to provide specific properties may provide a cost-effective alternative for the treatment of heavy metal contaminated soil and water. The application of natural zeolites in industrial pollution control is becoming important and the level of technical effort is increasingly expanding. The extent of application is unlikely to be related solely to their low cost, but also to improved properties and performance characteristics, which will advance the practical implementation of natural zeolites' technology. 相似文献
10.
Eric Keto Roger Ball John Arens Garrett Jernigan Margaret Meixner 《Journal of Infrared, Millimeter and Terahertz Waves》1992,13(11):1709-1725
We present a characterization of some processes affecting the performance of solid state array cameras designed for ground based astronomical imaging in the 8–13μm atmospheric window. Our discussion includes a novel model for electron-hole generationrecombination noise based on the probable pathlength of an electron in a photoconductor. We use the Berkeley mid-IR Array Camera as an example. For this camera, the results show that the total optical system composed of the camera, a 3m telescope, and the atmosphere has an efficiency of about 3%, a 1σ noise equivalent flux density of 25 mJy min?1/2arcsec?2 measured over a Δλ/λ=10% band width, and a noise equivalent expressed as the ambient temperature thermal black body noise of 23%. 相似文献