Beyond low-order statistical response surfaces: latent variable regression for efficient, highly nonlinear fitting

The number and magnitude of process variation sources are increasing as we scale further into the nano regime. Today’s most successful response surface methods limit us to low-order forms-- linear, quadratic-- to make the fitting tractable. Unfortunately, not all variational scenarios are well modeled with low-order surfaces. We show how to exploit latent variable regression ideas to support efficient extraction of arbitrarily nonlinear statistical response surfaces. An implementation of these ideas called SiLVR, applied to a range of analog and digital circuits, in technologies from 90 to 45nm, shows significant improvements in prediction, with errors reduced by up to 21X, with very reasonable runtime costs

Practical, fast Monte Carlo statistical static timing analysis: Why and how

Abstract Statistical static timing analysis (SSTA) has emerged as an essential tool for nanoscale designs. Monte Carlo methods are universally employed to validate the accuracy of the approximations made in all SSTA tools, but Monte Carlo itself is never employed as a strategy for practical SSTA. It is widely believed to be "too slow" -despite an uncomfortable lack of rigorous studies to support this belief. We offer the first large-scale study to refute this belief. We synthesize recent results from fast quasi-Monte Carlo (QMC) deterministic sampling and efficient Karhunen-Loéve expansion (KLE) models of spatial correlation to show that Monte Carlo SSTA need not be slow. Indeed, we show for the ISCAS89 circuits, a few hundred, well-chosen sample points can achieve errors within 5%, with no assumptions on gate models, wire models, or the core STA engine, with runtimes less than 90 s

Effect of selective pretreatments and subsequent mixed enzyme treatment on properties of jute-cotton union fabric

451-467<span style="font-size: 16.0pt;font-family:Fd1490491-Identity-H;mso-bidi-font-family:Fd1490491-Identity-H">Jute-cotton (75:25) union furnishing fabric has been treated with varying dose of mixed enzyme (cellulase, xylanase and pectinase) system with or without selective pretreatments and the consequent changes in important textile-related properties of the fabric evaluated. For untreated jute-cotton union fabric, 4% (owf) mixed enzyme treatment at 55°C for 2 h using pH 4.8-5.0 is found to be optimum. Between cotton (warp) and jute (weft), enzyme action is found to be more pronounced in cotton than in jute. However, the degree of enzymatic hydrolysis and associated weight loss for jute are found to increase if the mixed enzyme treatment is done after selective pretreatments. 1 % NaOH pretreatment at 30°C for 30 min offers some unique advantages, except browning of surface colour, when subsequently treated with 4% (owf) mixed enzyme. Steaming of wetted  jute-cotton union fabric at 130°C for 5 min shows almost negligible weight loss and marginal or no strength loss, although the reduction in stiffness in jute is poor and inadequate. Conventional scouring followed by 2% H2O2 bleaching with stabilizer A WNI instead of sodium metasilicate makes the fabric most suited for subsequent 4% mixed enzyme treatment. The use of 5 steel balls in the rotating beaker of the launder-O-meter during the enzyme treatment is found to be very useful for the removal of surface fuzz. Changes in functional group pattern and chemical composition of jute have also been analyzed after the treatments. Scanning electron microscopic and X-ray crystallographic studies respectively reveal the changes in the surface morphological features and fine structure of differently treated jute component of jutecotton union fabric. There is apparent increase or decrease in X-ray crystallinity due to associated mass loss from noncrystalline <span style="font-size: 16.0pt;font-family:Fd1490491-Identity-H;mso-bidi-font-family:Fd1490491-Identity-H">zone/crystalli ne interface for different pretreatments and subsequent enzymatic hydrolysis. </span

Efficacy of selective surfactants/detergents as washing agents on soiled white and dyed cotton fabrics

223-232Four different types of surfactant, namely alkyl benzene sulphonate (A), sodium lauryl sulphate (B), glycerol monostearate (C) and distearyl dimethyl ammonium chloride (D), have been used in single and multiple washing of a soiled white/dyed cotton fabric to determine their critical micelle concentration (CMC) values and to assess their washing performance in terms of changes in some of the physical properties of fabrics, per cent soil removal from soiled white fabric and maximum retention of colour depth of dyed fabric. The washing performance of each surfactant at lower concentration level by multiple wash cycles has also been studied. Wash fastness rating by grey scale and washing performance in terms of retention of colour depth of reactive dye dyed cotton fabric have been assessed and compared by measuring the corresponding K/S values and colour difference values after washing with these surfactants by ISO-II and ISO-III methods. It is observed that the CMC value and the corresponding degree of soil removal at CMC level are 1.9 % and 90.8 % for surfactant A, 1.5 % and 90.6 % for surfactant B, 2 % and 92 % for surfactant C, and 1% and 39.4 % for surfactant D respectively. On multiple wash, the surfactants C and D do not show good performance at lower concentration (0.5-1%), while the surfactant B is found to be better than others. Considering the changes in physical properties of fabrics after washing, washing performance, critical micelle concentration of surfactants and retention of colour depth after washing, the surfactant B shows an overall balanced performance

Hydrogen peroxide and potassium per-oxo-disulphate combined room temperature bleaching of jute, cotton and jute-cotton union fabrics — An energy-efficient ecofriendly process

221-231A method for room temperature bleaching of jute, cotton and jute-cotton union fabrics using a combination of H₂O₂ and K₂S₂O₈ has been optimized. The measurement of physical properties, such as breaking tenacity, weight loss and surface appearance, including SEM study indicates that the proposed room temperature bleaching process is less damaging to the three types of fabrics studied as compared to conventional hot (85ºC) H₂O₂ bleaching. The whiteness index is within the acceptable range. The suggested reaction mechanism indicates that K₂S₂O₈ acts as a peroxide booster showing a synergistic action. This room temperature bleaching process is energy efficient, ecofriendly and economical, which can be easily adopted by both small scale and large scale sectors

Fault analysis in analog circuits through language manipulation and abstraction

Each year automotive systems are becoming smarter thanks to their enhancement with sensing, actuation and computation features. The recent advancements in the field of autonomous driving have increased even more the complexity of the electronic components used to provide such services. ISO 26262 represents the natural response to the growing concerns in terms of the functional safety of electrical safety-related systems in this area. However, if the functional safety analysis of digital devices is quite a stable methodology, the same analysis for analog components is still in its infancy. This paper aims to explore the problem of fault analysis in analog circuits and how it can be integrated into the design processes with minimum effort. The methodology is based on analog language manipulation, analog fault instrumentation and automatic abstraction. An efficient and comprehensive flow for performing such an activity is proposed and applied to complex case studies