Graphene nanoribbons (GNRs) are considered as a prospective interconnect material. A comprehensive conductance and delay analysis of GNR interconnects is presented in this paper. Using a simple ...tight-binding model and the linear response Landauer formula, the conductance model of GNR is derived. Several GNR structures are examined, and the conductance among them and other interconnect materials e.g., copper (Cu), tungsten (W), and carbon nanotubes (CNTs) is compared. The impact of different model parameters (i.e., bandgap, mean free path, Fermi level, and edge specularity) on the conductance is discussed. Both global and local GNR interconnect delays are analyzed using an RLC equivalent circuit model. Intercalation doping for multilayer GNRs is proposed, and it is shown that in order to match (or better) the performance of Cu or CNT bundles at either the global or local level, multiple zigzag-edged GNR layers along with proper intercalation doping must be used and near-specular nanoribbon edge should be achieved. However, intercalation-doped multilayer zigzag GNRs can have better performance than that of W, implying possible application as local interconnects in some cases. Thus, this paper identifies the on-chip interconnect domains where GNRs can be employed and provides valuable insights into the process technology development for GNR interconnects.
This paper reviews the current state of research in carbon-based nanomaterials, particularly the one-dimensional (1-D) forms, carbon nanotubes (CNTs) and graphene nanoribbons (GNRs), whose promising ...electrical, thermal, and mechanical properties make them attractive candidates for next-generation integrated circuit (IC) applications. After summarizing the basic physics of these materials, the state of the art of their interconnect-related fabrication and modeling efforts is reviewed. Both electrical and thermal modeling and performance analysis for various CNT- and GNR-based interconnects are presented and compared with conventional interconnect materials to provide guidelines for their prospective applications. It is shown that single-walled, double-walled, and multiwalled CNTs can provide better performance than that of Cu. However, in order to make GNR interconnects comparable with Cu or CNT interconnects, both intercalation doping and high edge-specularity must be achieved. Thermal analysis of CNTs shows significant advantages in tall vias, indicating their promising application as through-silicon vias in 3-D ICs. In addition to on-chip interconnects, various applications exploiting the low-dimensional properties of these nanomaterials are discussed. These include chip-to-packaging interconnects as well as passive devices for future generations of IC technology. Specifically, the small form factor of CNTs and reduced skin effect in CNT interconnects have significant implications for the design of on-chip capacitors and inductors, respectively.
•The e-commerce sales mode and information sharing are considered.•Manufacturer’s investment efficiency affects parties’ sales mode selection.•Information sharing strategy affects parties’ sales mode ...preferences.•E-retailer’s prediction accuracy affects both parties’ optimal decisions.•Players can benefit from more accurate prediction information.
Demand forecasting is important information for all enterprises. Accurate forecast information determines the success of supply chain operations. This paper studies the selection strategy of e-commerce sales mode and information sharing strategy in a dual-channel supply chain. The manufacturer and e-retailer enter a Stackelberg competition. The e-retailer independently decides to share or not share forecasting demand information to the manufacturer. The results show that only if the investment efficiency of the manufacturer’s after-sales service is high, e-retailer is willing to share demand forecasting information. Information sharing does not always add value to the e-retailer, which may lead to the ‘precision trap’ of the e-retailer. Moreover, forecasting accuracy always has a positive impact on the e-retailer’s profit. However, the manufacturer would benefit from more accurate forecasting demand in the case of sharing information. Otherwise, prediction accuracy is negatively correlated with the manufacturer’s profit. Besides, the selection strategy of e-commerce sales mode depends on the level of the manufacturer’s investment efficiency. Specifically, if the manufacturer invests in after-sales service more efficiently, platform sales mode is preferred. If not, they prefer wholesale sales mode.
Ubiquitous in eukaryotes, circular RNAs (circRNAs) comprise a large class of mostly non-coding RNAs produced by back-splicing. Although some circRNAs have demonstrated biochemical activities, whether ...most circRNAs are functional is unknown. Here, we test the hypothesis that circRNA production primarily results from splicing error and so is deleterious instead of beneficial. In support of the error hypothesis, our analysis of RNA sequencing data from 11 shared tissues of humans, macaques, and mice finds that (1) back-splicing is much rarer than linear-splicing, (2) the rate of back-splicing diminishes with the splicing amount, (3) the overall prevalence of back-splicing in a species declines with its effective population size, and (4) circRNAs are overall evolutionarily unconserved. We estimate that more than 97% of the observed circRNA production is deleterious. We identify a small number of functional circRNA candidates, and the genome-wide trend strongly suggests that circRNAs are largely non-functional products of splicing errors.
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•The rate of back-splicing for a gene declines with its degree of splicing•The abundance of back-splicing in a species declines with its effective population size•Mammalian circRNAs are overall evolutionarily non-conserved•More than 97% of the observed circRNA production is deleterious
Circular RNAs (circRNAs) comprise a large class of mostly non-coding RNAs generated through back-splicing of pre-mRNAs, but the biological functions of circRNAs are largely unknown. Xu and Zhang provide evidence that most mammalian circRNAs are products of splicing errors and likely do not confer benefits.
Concrete filled stainless steel tubular (CFSST) columns have attracted increasing research interests in the last decade. This paper briefly introduces the material properties of stainless steel and ...reviews recent research on behaviour of CFSST columns and joints at both ambient and elevated temperatures. The reviewed studies include tests of bond behaviour between the stainless steel tube and core concrete, and the static behaviour of CFSST stub columns, slender columns, beams, stainless steel-concrete-carbon steel double-skin tubular columns, and concrete filled bimetallic tubular columns. The cyclic behaviour of CFSST beam-columns under combined axial and lateral cyclic loading as well as the impact behaviour of CFSST columns is also introduced. Fire test results of full-scale CFSST columns are presented along with finite element analysis results. The behaviour of composite joints with CFSST columns is also briefly reviewed in this paper. Based on the previous research, future research directions on CFSST are summarised and discussed.
•Behaviour of CFSST columns under various conditions•Behavior of composite joints with CFSST members•Further research needs of CFSST columns and structures.
A lightweight graphene foam composite with a density of 0.06 g/cm3 is developed. It shows a EMI shielding effectiveness of 30 dB and specific shielding effectiveness of 500 dB·cm3/g, which surpasses ...the best values of metals and other carbon‐based composites. In addition, the excellent flexibility of this foam composite gives it a stable EMI shielding performance under repeated bending.
It is debated whether the pervasive intergenic transcription from eukaryotic genomes has functional significance or simply reflects the promiscuity of RNA polymerases. We approach this question by ...comparing chance promoter activities with the expression levels of intergenic regions in the model eukaryote Saccharomyces cerevisiae. We build a library of over 10
strains, each carrying a 120-nucleotide, chromosomally integrated, completely random sequence driving the potential transcription of a barcode. Quantifying the RNA concentration of each barcode in two environments reveals that 41-63% of random sequences have significant, albeit usually low, promoter activities. Therefore, even in eukaryotes, where the presence of chromatin is thought to repress transcription, chance transcription is prevalent. We find that only 1-5% of yeast intergenic transcriptions are unattributable to chance promoter activities or neighboring gene expressions, and these transcriptions exhibit higher-than-expected environment-specificity. These findings suggest that only a minute fraction of intergenic transcription is functional in yeast.
•The MOL model had higher accuracy than OL model and ANN model.•PERCLOS and average pupil diameter are important eye metrics.•SDLP and steering wheel reversal are important driving behavior ...metrics.•Curvilinear relationship between KSS and important non-intrusive metrics was found.
Drowsy driving is a serious highway safety problem. If drivers could be warned before they became too drowsy to drive safely, some drowsiness-related crashes could be prevented. The presentation of timely warnings, however, depends on reliable detection. To date, the effectiveness of drowsiness detection methods has been limited by their failure to consider individual differences. The present study sought to develop a drowsiness detection model that accommodates the varying individual effects of drowsiness on driving performance.
Nineteen driving behavior variables and four eye feature variables were measured as participants drove a fixed road course in a high fidelity motion-based driving simulator after having worked an 8-h night shift. During the test, participants were asked to report their drowsiness level using the Karolinska Sleepiness Scale at the midpoint of each of the six rounds through the road course. A multilevel ordered logit (MOL) model, an ordered logit model, and an artificial neural network model were used to determine drowsiness.
The MOL had the highest drowsiness detection accuracy, which shows that consideration of individual differences improves the models’ ability to detect drowsiness. According to the results, percentage of eyelid closure, average pupil diameter, standard deviation of lateral position and steering wheel reversals was the most important of the 23 variables.
The consideration of individual differences on a drowsiness detection model would increase the accuracy of the model's detection accuracy.
•Experiments were conducted on RAC-FSST under lateral monotonic and cyclic loading.•The structural performance of RAC-FSST beam and beam-column were analyzed.•Finite element models were established ...for structural behaviour analysis and parametric analysis.•Modification methods for bearing capacity and hysteretic models were proposed.
This paper presents a series of experimental research on recycled aggregate concrete-filled stainless steel tubular (RAC-FSST) columns subjected to lateral monotonic and cyclic loading. The influence of axial load level, shear span ratio, and replacement ratio of recycled coarse aggregate on the RAC-FSST members under compression-bending loads is studied. The test results indicate that the RAC-FSST columns exhibit favorable ductility and energy dissipation capacity. The P-Δ skeleton curves of the columns subjected to lateral cyclic loading are similar to those of columns under monotonic loading. It indicates that, compared with the plastic damage of the concrete, the cyclic hardening characteristics of the stainless steel have more significant influence on the bearing capacity. Considering the characteristics of material loading and unloading criteria, a FE model is established to analyze the seismic performance of RAC-FSST, with the internal force development and stress distribution discussed. Based on the parametric analysis, the modification method of bearing capacity and the hysteretic models of RAC-FSST members are proposed.
Our study was aimed to evaluate the risk of a selected non-motor symptom, namely rapid eye movement behavior disorder (RBD) symptoms, among patients with newly diagnosed Parkinson disease compared ...with health controls.
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for meta-analysis and Cochrane manual were followed. Studies on RBD symptoms and PD were searched using PubMed, Embase, Web of Science and Cochrane library databases. All studies were published before August 3
, 2016. Eligible studies were those that reported a prevalence of RBD symptoms among newly diagnosed PD and health control. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by random-effected models. Heterogeneity across studies was assessed using Cochran Q and I
statistics.
We identified eight studies including 2462 PD patients and 3818 health controls. The overall prevalence of RBD symptoms in PD was 582/2462 (23.6%) compared to 131/3818 (3.4%) in control. And the pooled OR was 5.69 (95% CI 3.60 to 9.00; p = 0.001) with a moderate heterogeneity I
= 70.5%. After excluding the study of low weight, the overall polled OR was 3.54 (95% CI 2.77 to 4.52; p < 0.00001) and the heterogeneity was completely eliminated (I
= 0%).
RBD symptoms are common non-motor symptoms of PD, and people with PD are at a higher risk of developing RBD. Further studies are needed to understand the natural history of RBD symptoms in PD and its etiological and clinical implications.
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