30 research outputs found
Closed Form Expressions for Delay to Ramp Inputs for On-Chip VLSI RC Interconnect
In high speed digital integrated circuits, interconnects delay can be significant and should be included for accurate analysis. Delay analysis for interconnect has been done widely by using moments of the impulse response, from the explicit Elmore delay (the first moment of the impulse response) expression, to moment matching methods which creates reduced order trans impedance and transfer function approximations. However, the Elmore delay is fast becoming ineffective for deep submicron technologies, and reduced order transfer function delays are impractical for use as early-phase design metrics or as design optimization cost functions. This paper describes an approach for fitting moments of the impulse response to probability density functions so that delay can be estimated accurately at an early physical design stage. For RC trees it is demonstrated that the inverse gamma function provides a provably stable approximation. We used the PERI [13] (Probability distribution function Extension for Ramp Inputs) technique that extends delay metrics for ramp inputs to the more general and realistic non-step inputs. The accuracy of our model is justified with the results compared with that of SPICE simulations. KeywordsŸ Moment Matching, On-Chip Interconnect, Probability Distribution function, Cumulative Distribution function, Delay calculation, Slew Calculation, Beta Distribution, VLSI
Isolation and characterization of phthalates from Brevibacterium mcbrellneri that cause cytotoxicity and cell cycle arrest
Bacteria belonging to the family Brevibacterieae are ubiquitous Gram positive organisms that are responsible for the feet odour and cheese aroma. Brevibacterium mcbrellneri is a relatively new member belonging to Brevibac- terieae. In the current manuscript we discuss isolation of biologically active metabolites from Brevibacterium mcbrellneri. Two aromatic esters were isolated from Brevibacterium mcbrellneri by âBioassay guided fractiona- tion strategyâ and identified as di-(2-ethylhexyl) phthalate and dibutyl phthalate by chemical characterization using biophysical techniques. The phthalate compounds show broad spectrum antibacterial activity and mosquito larvi-cidal activity. Mosquito larvicidal activity has been attributed to inhibition of
acetylcholinesterase enzyme activity. These compounds were found to be cytotoxic in multiple cell lines causing cell cycle arrest in G1 phase
New data about the suspensor of succulent angiosperms : ultrastructure and cytochemical study of the embryo-suspensor of Sempervivum arachnoideum L. and Jovibarba sobolifera (Sims) Opiz
The development of the suspensor in two species - Sempervivum arachnoideum and Jovibarba sobolifera - was investigated using cytochemical methods, light and electron microscopy. Cytological processes of differentiation in the embryo-suspensor were compared with the development of embryo-proper. The mature differentiated suspensor consists of a large basal cell and three to four chalazal cells. The basal cell produces haustorial branched invading ovular tissues. The walls of the haustorium and the micropylar part of the basal cell form the wall ingrowths typical for a transfer cells. The ingrowths also partially cover the lateral wall and the chalazal wall separating the basal cell from the other embryo cells. The dense cytoplasm filling the basal cell is rich in: numerous polysomes lying free or covering rough endoplasmic reticulum (RER), active dictyosomes, microtubules, bundles of microfilaments, microbodies, mitochondria, plastids and lipid droplets. Cytochemical tests (including proteins, insoluble polysaccharides and lipids are distributed in the suspensor during different stages of embryo development) showed the presence of high amounts of macromolecules in the suspensor cells, particularly during the globular and heart-shaped phases of embryo development. The protein bodies and lipid droplets are the main storage products in the cells of the embryo-proper. The results of Auramine 0 indicate that a cuticular material is present only on the surface walls of the embryo-proper, but is absent from the suspensor cell wall. The ultrastructural features and cytochemical tests indicate that in the two species - S. arachnoideum and J. sobolifera - the embryo-suspensor is mainly involved in the absorption and transport of metabolites from the ovular tissues to the developing embryo-proper
Intelligent Fruit Yield Estimation for Orchards Using Deep Learning Based Semantic Segmentation TechniquesâA Review
Article number 684328Smart farming employs intelligent systems for every domain of agriculture to obtain sustainable economic growth with the available resources using advanced technologies. Deep Learning (DL) is a sophisticated artificial neural network architecture that provides state-of-the-art results in smart farming applications. One of the main tasks in this domain is yield estimation. Manual yield estimation undergoes many hurdles such as labor-intensive, time-consuming, imprecise results, etc. These issues motivate the development of an intelligent fruit yield estimation system that offers more benefits to the farmers in deciding harvesting, marketing, etc. Semantic segmentation combined with DL adds promising results in fruit detection and localization by performing pixel-based prediction. This paper reviews the different literature employing various techniques for fruit yield estimation using DL-based semantic segmentation architectures. It also discusses the challenging issues that occur during intelligent fruit yield estimation such as sampling, collection, annotation and data augmentation, fruit detection, and counting. Results show that the fruit yield estimation employing DL-based semantic segmentation techniques yields better performance than earlier techniques because of human cognition incorporated into the architecture. Future directions like customization of DL architecture for smart-phone applications to predict the yield, development of more comprehensive model encompassing challenging situations like occlusion, overlapping and illumination variation, etc., were also discussed.Ministerio de EconomĂa y Competitividad ( España) CEI-15-AGR278, US-126367
Creating livable subdivisions using stormwater, recycled water and groundwater
Integration of green infrastructure (comprising urban lakes, wetlands and parklands) within an urban centre subdivision can significantly improve its livability. Stormwater generated within the urban centre, which is often considered as water carrying significant amounts of pollutants, can be used to create green infrastructure within the subdivision. In addition, recently, âsewer miningâ is being used to supplement the non-potable water for urban centres. This source of recycled water is primarily used to satisfy the water required to maintain healthy green infrastructure. Extensive research conducted in recent years have also led to the plan of utilizing constructed lakes and wetlands, as part of green infrastructures, for storing and improving stormwater quality. Furthermore, they serve as significant water features within an urban centre increasing property values. In this work, we present a case study of a local government area (LGA) in Western Sydney, to provide some insights on how using urban lakes (which besides serving as stormwater purifying system) can greatly add to recreational value to a subdivision. City Councils in Western Sydney have successfully created parklands and physical exercise amenities around these constructed wetlands and lakes. These areas attract a large number of visitors throughout the year. The beneficial value of the urban lakes is demonstrated by the increasing values of the properties which are located around these lakes. We conclude that by employing best practices for managing stormwater runoff provide both socioeconomic and environmental benefits to urban centres, and cansignificantly increase the economic value of the region