Static locality analysis for cache management

Most memory references in numerical codes correspond to array references whose indices are affine functions of surrounding loop indices. These array references follow a regular predictable memory pattern that can be analysed at compile time. This analysis can provide valuable information like the locality exhibited by the program, which can be used to implement more intelligent caching strategy. In this paper we propose a static locality analysis oriented to the management of data caches. We show that previous proposals on locality analysis are not appropriate when the proposals have a high conflict miss ratio. This paper examines those proposals by introducing a compile-time interference analysis that significantly improve the performance of them. We first show how this analysis can be used to characterize the dynamic locality properties of numerical codes. This evaluation show for instance that a large percentage of references exhibit any type of locality. This motivates the use of a dual data cache, which has a module specialized to exploit temporal locality, and a selective cache respectively. Then, the performance provided by these two cache organizations is evaluated. In both organizations, the static locality analysis is responsible for tagging each memory instruction accordingly to the particular type(s) of locality that it exhibits.Peer ReviewedPostprint (published version

Sexual Selection and Mixed Sex Expression: Adolescent Protandry, Phenotypic Tradeoffs and ‘Unconventional\u27 Sex Allocation Estimates in a Protandric-Simultaneous Hermaphrodite

In protandric-simultaneous (PS) hermaphrodites, individuals invariably reproduce as males first and later in life as simultaneous hermaphrodites. In this study, the shrimp Lysmata wurdemanni (Gibbes, 1850) was used as a model to (i) test for the role of sexual selection (male-male competition) in explaining the early male phase and size-dependent sex allocation (SDSA) in PS hermaphrodites, (ii) examine the tradeoff between the male and female function in hermaphrodites, and (iii) determine if SDSA also takes place in the form of sex-specific behaviors and anatomical structures. In L. wurdemanni, male mating ability was size- and sex-dependent; greater for small than for large hermaphrodites and for males than hermaphrodites matched in body size. The above explains the adaptive value of the early male phase in PS hermaphrodites; small individuals should speed up sperm production and delay female reproduction to profit from male mating opportunities that are the greatest when small. Size-dependent male mating ability also suggests that small hermaphrodites should produce proportionally more sperm than ova compared to large hermaphrodites, a prediction supported by data. Sex allocation, measured as sex-specific behaviors and anatomical structures, was also size-dependent. No tradeoff between ova and sperm mass was found. However, among-individual variation in resource acquisition was considerable, suggesting that the observed lack of a statistical relationship between sperm and ova mass does not necessarily imply the absence of sex allocation tradeoffs in L. wurdemanni. Sexual selection is most relevant in PS hermaphrodites, SDSA also involves sex-specific behaviors, and morphological features, and variation in resource acquisition and allocation can explain the apparent absence of sex allocation tradeoffs

Do fungi need to be included within environmental radiation protection assessment models?

Fungi are used as biomonitors of forest ecosystems, having comparatively high uptakes of anthropogenic and naturally occurring radionuclides. However, whilst they are known to accumulate radionuclides they are not typically considered in radiological assessment tools for environmental (non-human biota) assessment. In this paper the total dose rate to fungi is estimated using the ERICA Tool, assuming different fruiting body geometries, a single ellipsoid and more complex geometries considering the different components of the fruit body and their differing radionuclide contents based upon measurement data. Anthropogenic and naturally occurring radionuclide concentrations from the Mediterranean ecosystem (Spain) were used in this assessment. The total estimated weighted dose rate was in the range 0.31–3.4 μGy/h (5th–95th percentile), similar to natural exposure rates reported for other wild groups. The total estimated dose was dominated by internal exposure, especially from 226Ra and 210Po. Differences in dose rate between complex geometries and a simple ellipsoid model were negligible. Therefore, the simple ellipsoid model is recommended to assess dose rates to fungal fruiting bodies. Fungal mycelium was also modelled assuming a long filament. Using these geometries, assessments for fungal fruiting bodies and mycelium under different scenarios (post-accident, planned release and existing exposure) were conducted, each being based on available monitoring data. The estimated total dose rate in each case was below the ERICA screening benchmark dose, except for the example post-accident existing exposure scenario (the Chernobyl Exclusion Zone) for which a dose rate in excess of 35 μGy/h was estimated for the fruiting body. Estimated mycelium dose rate in this post-accident existing exposure scenario was close to the 400 μGy/h benchmark for plants, although fungi are generally considered to be less radiosensitive than plants. Further research on appropriate mycelium geometries and their radionuclide content is required. Based on the assessments presented in this paper, there is no need to recommend that fungi should be added to the existing assessment tools and frameworks; if required some tools allow a geometry representing fungi to be created and used within a dose assessment

Knowledge-based supervision and control of wastewater treatment plant: a real-time implementation

The hardware architecture and the software development of a real-time knowledge-based distributed control system for the supervision of a wastewater treatment pilot plant are presented. The operation scheme is based on an A²/O system (anaerobic, anoxic, oxic) and includes organic matter removal, nitrification/denitrification, and Enhanced Biological Phosphorous Removal (EBPR). The hardware architecture involves different supervision levels, including two autonomous process computers (plant control and analysers control) and a PLC. The software architecture includes a Knowledge-Based Expert System (KBES) as the top control system. The KBES has been developed in G2, an expert system development environment based on object-oriented structural design. This system is fed with data obtained from the plant monitoring (in-line, on-line and off-line data) and with actuation data of the lower control levels. Using this information, the KBES supervises the pilot plant in order to help with fault detection and plant maintenance, but also modifies setpoints and other variables of the local control level to adapt the system to the different influent conditions. The overall system has been implemented and validated at pilot scale.Spanish Inter-Ministry Commission of Science and Technology (C.I.C.Y.T.) - BIO94-0679-C02, AMB97-0889-c03-01.Fundação Calouste Gulbenkian (FCG).Generalitat de Catalunya. Consell Interdepartamental de Recerca i Innovació Tecnològica (CIRIT)

Real-time expert control of a pilot WWTP with nitrogen and phosphorus removal

Fundação Calouste Gulbenkian; C.I.R.I.T. (Generalitat de Catalunya)

Knowledge-based supervision and control of WWTP: a real-time implementation

Fundação Calouste Gulbenkian (FCG) - post-doctoral research grant.Generalitat de Catalunya. Consell Interdepartamental de Recerca i Innovació Tecnològica (CIRIT) - predoctoral fellowship

A knowledge-based distributed system for supervision and control of wastewater treatment processes

This paper presents the hardware architecture and the software development of a real-time knowledge-based distributed control system for the supervision of a wastewater treatment pilot plant with biological removal of organic matter and nitrogen. A continuous monitoring of plant and controls data is used by an expert system developed in G2, a development environment based on object-oriented paradigm. A set of rules and procedures to help fault detection, plant maintenance, and nitrification - denitrification cycle operation was implemented and validated at pilot scale. The hardware architecture includes different supervision levels, including two autonomous process computers (plant control and analysers control).Fundação Calouste Gulbenkian (FCG) - postdoctoral research grant..Generalitat de Catalunya. Consell Interdepartamental de Recerca i Innovació Tecnològica (CIRIT) - predoctoral fellowship

Testing the Role of Male-Male Competition in the Evolution of Sexual Dimorphism: A Comparison Between Two Species of Porcelain Crabs

Theory predicts marked sexual dimorphism in terms of body size and body structures used as weapons (e.g. chelipeds) in gonochoric species with intense male sexual competition for receptive females and reduced or no sexual dimorphism in species where competition among males is trivial. We tested this hypothesis using a pair of closely-related species of symbiotic porcelain crabs as a model. In one species that inhabits sea anemones solitarily, competition among males for receptive females is unimportant. In a second species that dwells as dense aggregations on sea urchins, malemale competition for sexual partners is recurrent. We expected considerable sexual dimorphism in body size and weaponry in the urchin-dwelling crab and reduced sexual dimorphism in the anemone-dwelling crab. In agreement with expectations, in the urchin-dwelling crab, male body size was, on average, larger than that of females and males invested considerably more to cheliped length than females. Also supporting theoretical considerations, in the anemone-dwelling crab, sexual dimorphism in terms of body size was not detected and differences between the sexes in investment to cheliped length were minor. Interestingly, chelipeds were more developed both in males and females of the anemone-dwelling crab than in the urchin-dwelling crab as a result of the importance of these structures for monopolization of their naturally scarce anemone hosts. Another difference between the studied species was the existence of two clearly distinguishable ontogenetic phases in males of the urchin-dwelling crab but not in males of the anemone-dwelling crab. Whether the two different male morphs display different male reproductive strategies in the urchin-dwelling crab remains to be addressed. Other conditions that might additionally explain the observed differences in sexual dimorphism (e.g. female mate choice) between the studied species remain to be explored. © 2011 The Linnean Society of London