As feature sizes shrink, transient failures of on-chip network links become a critical problem. At the same time, many applications
require guarantees on both message arrival probability and response time. We address the problem of transient link failures
by means of temporally and spatially redundant transmission of messages, such that designer-imposed message arrival probabilities
are guaranteed. Response time minimisation is achieved by a heuristic that statically assigns multiple copies of each message
to network links, intelligently combining temporal and spatial redundancy. Concerns regarding energy consumption are addressed
in two ways. First, we reduce the total amount of transmitted messages, and, second, we minimise the application response
time such that the resulted time slack can be exploited for energy savings through voltage reduction. The advantages of the
proposed approach are guaranteed message arrival probability and guaranteed worst case application response time. 相似文献
Theoretical treatments forecast that bistable CMOS devices using electronic charge as a state variable will operate at their maximum thermal dissipation limit possibly as early as 2012. The problem is further compounded by increasing manufacturing challenges associated with the ever decreasing logic switch dimensions. These challenges require the development of new fabrication strategies that replace or complement current top-down lithography with bottom-up protocols using controlled self-assembly of nanomaterial building blocks. To answer some of these issues, this paper focuses on a new device paradigm consisting of an arene-metal-arene conformational switch, addressable through capacitive, inductive, or resonant-tunneling field coupling. The operating principle is based on voltage-tunable modulation in quantum electron transmission. The switch is open (off) when the metal ion is displaced to a position at a C-H bond on the arene ring due to an externally applied bias. Conversely, when the external bias is removed, the metal ion moves to an axis- symmetric position on the arene ring, and the switch is closed (on). The paper presents a summary of the architecture, operating principle, and advantages of the conformational switch, along with associated findings from proof-of-concept theoretical and experimental studies of its target specifications and performance. The paper also discusses opportunities and challenges related to the integration of conformational switches into hybrid CMOS-molecular and monolithic (all molecular) circuits. 相似文献
After the break-up of Czechoslovakia in 1993 the primary metrological standards authority almost fully remained in Slovakia. So we had to build our primary vacuum metrology anew. But we could do it using uptodate techniques that are more effective and they enable us to fulfil our task more effectively and in a shorter time.The steady demand to widen the lower pressure range and a steady demand for maximal accuracy collide with the financial possibilities open to a small country. So it is impossible to follow the classical pattern for the vacuum standards: liquid columns, static expansion system and dynamic expansion system. But it is possible to utilize contemporary progress in construction of piston manometers. This enables us to discard liquid column and static expansion techniques in favour of piston technique [Tesar J, Prazak D. Vacuum 2002; 67: 311, Tesar J, Prazak D, Krajicek Z. In:Proceedings of international symposium on Pressure and Vacuum, 2003. p. 169, Tesar J, Repa P, Prazak D, Krajicek Z, Peksa L. Vacuum 2004; 76: 491.]. Such system fulfils all the needs of a little industrial country and is economically acceptable. 相似文献
In this paper, we introduce the LOPOCOS (Low Power Co-synthesis) system, a prototype CAD tool for system level co-design. LOPOCOS targets the design of energy-efficient embedded systems implemented as heterogeneous distributed architectures. In particular, it is designed to solve the specific problems involved in architectures that include dynamic voltage scalable (DVS) processors. The aim of this paper is to demonstrate how LOPOCOS can support the system designer in identifying energy-efficient hardware/software implementations for the desired embedded systems. Hence, highlighting the necessary optimization steps during design space exploration for DVS enable architectures. The optimization steps carried out in LOPOCOS involve component allocation and task/communication mapping as well as scheduling and dynamic voltage scaling. LOPOCOS has the following key features, which contribute to this energy efficiency. During the voltage scaling valuable power profile information of task execution is taken into account, hence, the accuracy of the energy estimation is improved. A combined optimization for scheduling and communication mapping based on genetic algorithm, optimizes simultaneously execution order and communication mapping towards the utilization of the DVS processors and timing behaviour. Furthermore, a separation of task and communication mapping allows a more effective implementation of both task and communication mapping optimizationsteps. Extensive experiments are conducted to demonstrate the efficiency of LOPOCOS. We report up to 38% higher energy reductions compared to previous co-synthesis techniques for DVS systems. The investigations include a real-life example of an optical flow detection algorithm. 相似文献
Never before have regional scientists had access to individual census data for an entire country. The paper describes the application of a taxonomic procedure to classify the 15.6 million households identified by the 1971 Italian census. The results are important both for what they reveal about Italian social structure and because they provide a basis for a constructing aggregate census data so that within area variations are retained. 相似文献
A promising catalytic system for the low temperature oxidation of methane to a methanol derivative has been investigated under both batch and semi-continuous operation in two different reactor types. The system comprises of a bimetallic palladium and copper(II) chloride catalyst contained in a trifluoroacetic acid (TFA) and an aqueous phase. Methane, oxygen and a co-reductant carbon monoxide constitute the gas phase. Typical operating conditions were a temperature of 85 °C and a pressure of 83 bar.
The yields of the methyl trifluoroacetate product observed in this present work were less than those obtained in other batch autoclave works, which employed only 4 ml of liquid phase, compared with 50 ml in this study. Furthermore, an encouraging initial product formation rate of ca. 40 mol/m3 h, quickly decreased after the first hour, and came to an apparent end after only 2 h. This observation had not been reported previously.
Work performed in a semi-continuous porous tube reactor (300 ml of re-circulating liquid phase) also showed the same reaction characteristics as in the batch reactor. Thus, the deteriorating product formation rate cannot be attributed to gaseous reactant depletion (batch operation). The results suggest problems associated with catalyst instabilities, e.g. with the previously elucidated Wacker chemistry. 相似文献
A new definition of the testability transfer factor for circuit components that provides better sensitivity with respect to parametric deviations is presented. New equations for the testability measures in a mixed-signal core are given. Testability analysis is used for test-pattern generation and for consideration of inserting wrapper cells. The simulation results show the effectiveness of the approach. 相似文献
This paper employs dissipativity theory for the global analysis of limit cycles in particular dynamical systems of possibly high dimension. Oscillators are regarded as open systems that satisfy a particular dissipation inequality. It is shown that this characterization has implications for the global stability analysis of limit cycle oscillations: i) in isolated oscillators, ii) in interconnections of oscillators, and iii) for the global synchrony analysis in interconnections of identical oscillators 相似文献
This paper presents HotSpot-a modeling methodology for developing compact thermal models based on the popular stacked-layer packaging scheme in modern very large-scale integration systems. In addition to modeling silicon and packaging layers, HotSpot includes a high-level on-chip interconnect self-heating power and thermal model such that the thermal impacts on interconnects can also be considered during early design stages. The HotSpot compact thermal modeling approach is especially well suited for preregister transfer level (RTL) and presynthesis thermal analysis and is able to provide detailed static and transient temperature information across the die and the package, as it is also computationally efficient. 相似文献
A Cr/Al2O3 alkane dehydrogenation catalyst exhibits a maximum in ethylene yield during an ethane dehydrogenation cycle. Isotopic labelling experiments with monolabelled 13C-ethane and deuterium were used to elucidate whether the initial activity increase could be due to formation of an active, larger hydrocarbon intermediate on the surface. The results strongly indicate that this is not the case, and instead point to a traditional reaction cycle involving adsorption of ethane to form an ethyl species, followed by desorption of ethene and hydrogen. Transient kinetic data suggest that ethane adsorption is the rate-determining step of reaction. 相似文献