KAPow: A System Identification Approach to Online Per-Module Power Estimation in FPGA Designs

In a modern FPGA system-on-chip design, it is often insufficient to simply assess the total power consumption of the entire circuit by design-time estimation or runtime power rail measurement. Instead, to make better runtime decisions, it is desirable to understand the power consumed by each individual module in the system. In this work, we combine boardlevel power measurements with register-level activity counting to build an online model that produces a breakdown of power consumption within the design. Online model refinement avoids the need for a time-consuming characterisation stage and also allows the model to track long-term changes to operating conditions. Our flow is named KAPow, a (loose) acronym for ‘K’ounting Activity for Power estimation, which we show to be accurate, with per-module power estimates as close to ±5mW of true measurements, and to have low overheads. We also demonstrate an application example in which a permodule power breakdown can be used to determine an efficient mapping of tasks to modules and reduce system-wide power consumption by over 8%

Combinatorial Assortment Optimization

Assortment optimization refers to the problem of designing a slate of products to offer potential customers, such as stocking the shelves in a convenience store. The price of each product is fixed in advance, and a probabilistic choice function describes which product a customer will choose from any given subset. We introduce the combinatorial assortment problem, where each customer may select a bundle of products. We consider a model of consumer choice where the relative value of different bundles is described by a valuation function, while individual customers may differ in their absolute willingness to pay, and study the complexity of the resulting optimization problem. We show that any sub-polynomial approximation to the problem requires exponentially many demand queries when the valuation function is XOS, and that no FPTAS exists even for succinctly-representable submodular valuations. On the positive side, we show how to obtain constant approximations under a "well-priced" condition, where each product's price is sufficiently high. We also provide an exact algorithm for $k$-additive valuations, and show how to extend our results to a learning setting where the seller must infer the customers' preferences from their purchasing behavior

Mycoremediation of polycyclic aromatic hydrocarbons (PAH)-contaminated oil-based drill-cuttings

Spent white-rot fungi (Pleurotus ostreatus) substrate has been used to biotreat Nigerian oil-based drill cuttings containing polycyclic aromatic hydrocarbons (PAHs) under laboratory conditions. The Latin square (LS) experimental design was adopted in which four options of different treatment levels were tested in 10 L plastic reactors containing fixed masses of the drill cuttings and fresh top-soil inoculated with varying masses of the spent P. ostreatus substrate. Each option was replicated three times and watered every 3 days under ambient conditions for a period of 56 days. Microcosm analysis with a series II model 5890 AGILENT Hp® GC-FID showed that, the PAHs in the drill cuttings were mainly composed of 2 to 5 fused rings with molecular-mass ranging from 128 to 278 g/mol, while the total initial PAHs concentration of the drill cuttings was 806.31 mg/kg. After 56 days of composting, the total amount of residual PAHs in the drill cuttings decreased to between 19.75 and 7.62%, while the overall degradation of PAHs increased to between 80.25 and 92.38% with increasing substrate addition. Individual PAH degradation ranged from 97.98% in acenaphthene to 100% in fluorene, phenanthrene and anthracene. Statistical analysis, using the 2-factor analysis of variance (ANOVA), showed that there were no significant differences (p < 0.05) in the biodegradation of the PAHs due to the substrate levels applied and remediation period, as well as a nonsignificant (p < 0.05) interaction between substrate levels applied and remediation period. These results showed that spent white-rot fungi (P. ostreatus) substrate may be suitable for biotreating PAH-contaminated Nigerian oil-based drill cuttings.Key words: Drill-cuttings, polycyclic aromatic hydrocarbons Pleurotus ostreatus, mycoremediation, compostin

Listeners and Readers Generalize Their Experience With Word Meanings Across Modalities

Research has shown that adults' lexical-semantic representations are surprisingly malleable. For instance, the interpretation of ambiguous words (e.g., bark) is influenced by experience such that recently encountered meanings become more readily available (Rodd et al., 2016, 2013). However, the mechanism underlying this word-meaning priming effect remains unclear, and competing accounts make different predictions about the extent to which information about word meanings that is gained within one modality (e.g., speech) is transferred to the other modality (e.g., reading) to aid comprehension. In two Web-based experiments, ambiguous target words were primed with either written or spoken sentences that biased their interpretation toward a subordinate meaning, or were unprimed. About 20 min after the prime exposure, interpretation of these target words was tested by presenting them in either written or spoken form, using word association (Experiment 1, N = 78) and speeded semantic relatedness decisions (Experiment 2, N = 181). Both experiments replicated the auditory unimodal priming effect shown previously (Rodd et al., 2016, 2013) and revealed significant cross-modal priming: primed meanings were retrieved more frequently and swiftly across all primed conditions compared with the unprimed baseline. Furthermore, there were no reliable differences in priming levels between unimodal and cross-modal prime-test conditions. These results indicate that recent experience with ambiguous word meanings can bias the reader's or listener's later interpretation of these words in a modality-general way. We identify possible loci of this effect within the context of models of long-term priming and ambiguity resolution

The Geology of Ancient Fluvial and Lacustrine Systems in Arabia Terra and Melas Chasma, Mars

Fluvial and lacustrine processes were abundant on early Mars. However, key questions remain about the extent of these processes and the climate in which they formed. This thesis examines two regions of Mars, Arabia Terra and Melas Chasma, using high-resolution, remote sensing datasets, with a focus on (1) the influence of fluvial and lacustrine processes on the landscape and (2) the implications for the early martian climate and environment. I first investigate Arabia Terra, a Noachian region of the southern highlands, and have produced a regional map of fluvial landforms. Fluvial channels and paleolakes preserved as inverted relief are pervasive throughout Arabia Terra and may represent the depositional component of a regional, south to north fluvial transport system. In addition, I have produced a geological map of one of these inverted systems, which reveals a complex stratigraphy and demonstrates that fluvio-lacustrine processes are concentrated on the oldest terrains. These fluvial systems are strongly consistent with widespread precipitation and runoff across early Mars. The second region of investigation is the Hesperian south-western Melas Chasma basin, part of the Valles Marineris canyon system. Here I have produced a map of fluvial landforms, which indicates that fluvial processes were episodic and extended over a protracted period of time. I also examine the stratigraphic sequence within the central palaeolake in the basin, where evidence for episodic aqueous processes is also identifed. The south-western Melas Chasma basin provides strong evidence that fluvio-lacustrine processes on Mars continued for much of the early and middle history of Mars

Flavor-symmetry Breaking with Charged Probes

We discuss the recombination of brane/anti-brane pairs carrying $D3$ brane charge in $AdS_5 \times S^5$. These configurations are dual to co-dimension one defects in the ${\cal N}=4$ super-Yang-Mills description. Due to their $D3$ charge, these defects are actually domain walls in the dual gauge theory, interpolating between vacua of different gauge symmetry. A pair of unjoined defects each carry localized $(2+1)$ dimensional fermions and possess a global $U(N)\times U(N)$ flavor symmetry while the recombined brane/anti-brane pairs exhibit only a diagonal U(N). We study the thermodynamics of this flavor-symmetry breaking under the influence of external magnetic field.Comment: 21 pages, 10 figure

Bidirectional associations between word memory and one-legged balance performance in mid and later life

Background: Age-related changes in cognitive and balance capabilities are well-established, as is their correlation with one another. Given limited evidence regarding the directionality of associations, we aimed to explore the direction and potential explanations of associations between word memory and one-legged balance performance in mid-later life. / Methods: A total of 3062 participants in the Medical Research Council National Survey of Health and Development, a British birth cohort study, were included. One-legged balance times (eyes closed) were measured at ages 53, 60–64 and 69 years. Word memory was assessed at ages 43, 53, 60–64 and 69 with three 15-item word-recall trials. Autoregressive cross-lagged and dual change score models assessed bidirectional associations between word memory and balance. Random-effects models quantified the extent to which these associations were explained by adjustment for anthropometric, socioeconomic, behavioural and health status indicators. / Results: Autoregressive cross-lagged and dual change score models suggested a unidirectional association between word memory and subsequent balance performance. In a sex-adjusted random-effects model, 1 standard deviation increase in word memory was associated with 9% (7,12%) higher balance performance at age 53. This association decreased with age (−0.4% /year (−0.6,-0.1%). Education partially attenuated the association, although it remained in the fully-adjusted model (3% (0.1,6%)). / Conclusions: There was consistent evidence that word memory is associated with subsequent balance performance but no evidence of the reverse association. Cognitive processing plays an important role in the balance process, with educational attainment providing some contribution. These findings have important implications for understanding cognitive-motor associations and for interventions aimed at improving cognitive and physical capability in the ageing population