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排序方式: 共有188条查询结果,搜索用时 15 毫秒
1.
Mehra A. Indiresan A. Shin K.G. 《IEEE transactions on pattern analysis and machine intelligence》1997,23(10):616-634
We propose architectural mechanisms for structuring host communication software to provide QoS guarantees. We present and evaluate a QoS sensitive communication subsystem architecture for end hosts that provides real time communication support for generic network hardware. This architecture provides services for managing communication resources for guaranteed QoS (real time) connections, such as admission control, traffic enforcement, buffer management, and CPU and link scheduling. The architecture design is based on three key goals: maintenance of QoS guarantees on a per connection basis, overload protection between established connections, and fairness in delivered performance to best effort traffic. Using this architecture we implement real time channels, a paradigm for real time communication services in packet switched networks. The proposed architecture features a process per channel model that associates a channel handler with each established channel. The model employed for handler execution is one of “cooperative” preemption, where an executing handler yields the CPU to a waiting higher priority handler at well defined preemption points. The architecture provides several configurable policies for protocol processing and overload protection. We present extensions to the admission control procedure for real time channels to account for cooperative preemption and overlap between protocol processing and link transmission at a sending host. We evaluate the implementation to demonstrate the efficacy with which the architecture maintains QoS guarantees on outgoing traffic while adhering to the stated design goals 相似文献
2.
Crystallization kinetics of the Se80–x
Sb
x
Te20 (0x9) alloys have been studied using differential scanning calorimetry. The activation energies for the glass transition and that for crystallization have been determined from the heating rate dependence of the glass transition temperature and the peak crystallization temperature. The results have been analysed using the modified Kissinger's and Matusita's equations for the non-isothermal crystallization of materials. The variation of glass transition temperature with composition suggests that a small amount of Sb ( 4 at %) leads to an increase in the chain length of Se-Te, whereas further increase in Sb atomic per cent increases the number of Se-Te chains in the alloys. 相似文献
3.
Mehra A. Xin Zhang Ayon A.A. Waitz I.A. Schmidt M.A. Spadaccini C.M. 《Journal of microelectromechanical systems》2000,9(4):517-527
As part of a program to develop a micro gas turbine engine capable of producing 10-50 W of electrical power in a package less than one cubic centimeter in volume, we present the design, fabrication, packaging, and experimental test results for the 6-wafer combustion system for a silicon microengine. Comprising the main nonrotating functional components of the engine, the device described measures 2.1 cm×2.1 cm×0.38 cm and is largely fabricated by deep reactive ion etching through a total thickness of 3800 μm. Complete with a set of fuel plenums, pressure ports, fuel injectors, igniters, fluidic interconnects, and compressor and turbine static airfoils, this structure is the first demonstration of the complete hot flow path of a multilevel micro gas turbine engine. The 0.195 cm3 combustion chamber is shown to sustain a stable hydrogen flame over a range of operating mass flows and fuel-air mixture ratios and to produce exit gas temperatures in excess of 1600 K. It also serves as the first experimental demonstration of stable hydrocarbon microcombustion within the structural constraints of silicon. Combined with longevity tests at elevated temperatures for tens of hours, these results demonstrate the viability of a silicon-based combustion system for micro heat engine applications 相似文献
4.
The Internet infrastructure must evolve from best-effort service to meet the needs of different customers and applications. With Internet traffic differentiation, service providers can support a range of offerings, such as loss or delay bounds and network bandwidth allocation, to meet different performance requirements. The differentiated services (Diffserv) architecture provides a scalable approach, in which network access (or edge) devices aggregate traffic flows onto provisioned pipes that traverse a streamlined network core. We have identified the key requirements for provisioning Diffserv functions on Internet servers. Based on these requirements, we have implemented, and deployed, a policy-based architecture on IBM's AIX operating system that provides Diffserv services to both QoS-aware and -unaware applications 相似文献
5.
Microsystem Technologies - A low power, temperature compensated, robust design of CS amplifier is proposed in this paper. A new voltage reference is introduced to enhance reliability of the design... 相似文献
6.
Ronald E. Davis Dallas G. Denery David A. Kendrick Raman K. Mehra 《Computational Economics》2012,39(1):71-76
A continuous-time control model was formulated and fitted to macroeconomic data by an expert control engineer who worked at
NASA-AMES in the 1980s, Rodney C. Wingrove. Two articles were prepared and made available to the aerospace industry at that
time, however the authors feel that wider distribution of his study posthumously is warranted at this time. This introduction
to the two Wingrove articles that follow provides background information on the technologies Wingrove was working with, as
well as subsequent developments in both macroeconomic and engineering modeling and analysis technology. Our purpose is to
stimulate further research along the same lines which can potentially lead to structural and/or policy rule improvements that
can prevent the extremely turbulent abberations that have been seen in recent years, and promote steady growth with low inflation
and low unemployment in a sustainable way. Of particular concern is the exploding national debt problem. 相似文献
7.
8.
O’Neill M. Saggar S. Richards K. G. Luo J. Singh B. P. Mehra P. Forrestal P. J. 《Nutrient Cycling in Agroecosystems》2021,121(2-3):129-147
Nutrient Cycling in Agroecosystems - We quantified nitrous oxide emission factors (N2O EFs) for cattle urine patches established using two simulation methods: (1) a uniformly wetted area (UWA) and... 相似文献
9.
This paper presents an adaptive multiuser channel estimator using the reduced-Kalman least-mean-square (RK-LMS) algorithm.
The frequency-selective fading channel is modeled as a tapped-delay-line filter with smoothly time-varying Rayleigh distributed
tap coefficients. The multiuser channel estimator based on minimum-mean-square-error (MMSE) criterion is used to predict the
filter coefficients. We also present its convergence characteristics and tracking performance using the RK-LMS algorithm.
Unlike the previously available Kalman filtering algorithm based approach (Chen, Chen IEEE Trans Signal Process 49(7): 1523–1532, 2001) the incorporation of RK-LMS algorithm reduces the computational complexity of multiuser channel estimator
used in the code division multiple access wireless systems. The computer simulation results are presented to demonstrate the
substantial improvement in its tracking performance under the smoothly time-varying environment.
相似文献
D. K. MehraEmail: |
10.
S. Mehra 《国际生产研究杂志》2013,51(16):3299-3302
Due to the ever-changing dynamics of today's global market place, it is necessary to examine upcoming future trends that may impact businesses. Supply chains are a valuable component of all business planning, and hence, they must be continuously monitored. This paper reflects on the views and contributions of various authors writing on the crucial issue of managing supply chains. Specifically, topics such as relationship quality, performance, integration, responsiveness, risk management strategies, agility, and incentive systems in supply chains are addressed. 相似文献