Truncated Schwinger-Dyson Equations and Gauge Covariance in QED3

We study the Landau-Khalatnikov-Fradkin transformations (LKFT) in momentum space for the dynamically generated mass function in QED3. Starting from the Landau gauge results in the rainbow approximation, we construct solutions in other covariant gauges. We confirm that the chiral condensate is gauge invariant as the structure of the LKFT predicts. We also check that the gauge dependence of the constituent fermion mass is considerably reduced as compared to the one obtained directly by solving SDE.Comment: 17 pages, 11 figures. v3. Improved and Expanded. To appear in Few Body System

Effects Of Aging, Temperature, Moist Aggregates And Filler Type On Performance Of Warm Mix Asphalt Incorporating Rh-Wma Additive

Conventional Hot Mix Asphalt (HMA) has been the primary material used in pavement in past decades. Recently, compared to conventional HMA, Warm Mix Asphalt (WMA) has shown great potential and offers benefits not given by HMA, since the WMA can be produced at lower temperatures without affecting pavement performance. Since WMA additives can reduce the binder viscosity, the production and compaction temperatures can be lowered, compared to conventional HMA. One of the additives used to produce WMA is a type of wax named RH-WMA. In this thesis, the rheological properties of a conventional a virgin PG64 asphalt binder with and without RH-WMA at different aging conditions were investigated. The overall rheological binder tests results indicated that RH-WMA content had significant effects on the rheological parameters of asphalt binders in terms of viscosity, G*/sin δ and G*sin δ. Image analysis technique was used to classify the adhesive failure by using impact test. The impact test was conducted on a newly fabricated mould and the effects of aging conditions and test temperatures of asphalt binder incorporating RH-WMA were investigated. The analysis results showed that short-term aging and long-term aging of asphalt binder increased the percentage of adhesion failure. The construction temperature (mixing and compaction) was reduced by the addition of RH-WMA additive due to viscosity reduction. However, the reduction of mixing temperatures may prevent moisture from being completely evaporated from the aggregate and thus, effect the asphalt binder bond, making the mixture more susceptible to stripping. Two anti-stripping additives, namely hydrated lime and Pavement Modifier (PMD) were used to reduce the destructive effects of moisture. Effects of RH-WMA content, production and testing temperatures on mixture performance were investigated in terms of indirect tensile strength, resilient modulus and creep stiffness. The result indicates that both ITS and MR decreased as the RH-WMA content increased at the respective test and mixing temperatures. The effects of incomplete drying of aggregates on the mechanical properties of asphalt mixtures were clearly evident in this thesis. Therefore, the use of fully dried aggregates was important in ensuring satisfactory mix performance. Mixes prepared with 3% RH-WMA and compacted at 125°C° exhibit the best performance compare with HMA. Specimen incorporating PMD filler improved resistance to stripping compared to mixes with hydrated lime filler regardless of compaction temperature. The test results also indicated that aging improved the moisture resistance of WMA

Dynamic and Leakage Power-Composition Profile Driven Co-Synthesis for Energy and Cost Reduction

Recent research has shown that combining dynamic voltage scaling (DVS) and adaptive body bias (ABB) techniques achieve the highest reduction in embedded systems energy dissipation [1]. In this paper we show that it is possible to produce comparable energy saving to that obtained using combined DVS and ABB techniques but with reduced hardware cost achieved by employing processing elements (PEs) with separate DVS or ABB capability. A co-synthesis methodology which is aware of tasks’ power-composition profile (the ratio of the dynamic power to the leakage power) is presented. The methodology selects voltage scaling capabilities (DVS, ABB, or combined DVS and ABB) for the PEs, maps, schedules, and voltage scales applications given as task graphs with timing constraints, aiming to dynamic and leakage energy reduction at low hardware cost. We conduct detailed experiments, including a real-life example, to demonstrate the effectiveness of our methodology. We demonstrate that it is possible to produce designs that contain PEs with only DVS or ABB technique but have energy dissipation that are only 4.4% higher when compared with the same designs that employ PEs with combined DVS and ABB capabilities

Variation aware analysis of bridging fault testing

This paper investigates the impact of process variation on test quality with regard to resistive bridging faults. The input logic threshold voltage and gate drive strength parameters are analyzed regarding their process variation induced influence on test quality. The impact of process variation on test quality is studied in terms of test escapes and measured by a robustness metric. It is shown that some bridges are sensitive to process variation in terms of logic behavior, but such variation does not necessarily compromise test quality if the test has high robustness. Experimental results of Monte-Carlo simulation based on recent process variation statistics are presented for ISCAS85 and -89 benchmark circuits, using a 45nm gate library and realistic bridges. The results show that tests generated without consideration of process variation are inadequate in terms of test quality, particularly for small test sets. On the other hand, larger test sets detect more of the logic faults introduced by process variation and have higher test quality