Inferring Energy Bounds via Static Program Analysis and Evolutionary Modeling of Basic Blocks

The ever increasing number and complexity of energy-bound devices (such as the ones used in Internet of Things applications, smart phones, and mission critical systems) pose an important challenge on techniques to optimize their energy consumption and to verify that they will perform their function within the available energy budget. In this work we address this challenge from the software point of view and propose a novel parametric approach to estimating tight bounds on the energy consumed by program executions that are practical for their application to energy verification and optimization. Our approach divides a program into basic (branchless) blocks and estimates the maximal and minimal energy consumption for each block using an evolutionary algorithm. Then it combines the obtained values according to the program control flow, using static analysis, to infer functions that give both upper and lower bounds on the energy consumption of the whole program and its procedures as functions on input data sizes. We have tested our approach on (C-like) embedded programs running on the XMOS hardware platform. However, our method is general enough to be applied to other microprocessor architectures and programming languages. The bounds obtained by our prototype implementation can be tight while remaining on the safe side of budgets in practice, as shown by our experimental evaluation.Comment: Pre-proceedings paper presented at the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur, Belgium, 10-12 October 2017 (arXiv:1708.07854). Improved version of the one presented at the HIP3ES 2016 workshop (v1): more experimental results (added benchmark to Table 1, added figure for new benchmark, added Table 3), improved Fig. 1, added Fig.

The isotherm follower

The isotherm follower is an instrument that is capable of seeking out a given isotherm in the sea, locking on to the isotherm, following it up and down, and recording its depth with respect to time. This instrument has been employed singly and in triangular arrangements of three to provide the speed and direction of internal waves. It has proven to be valuable in determining the nature of vertical oscillations of sea temperature

On strongly chordal graphs that are not leaf powers

A common task in phylogenetics is to find an evolutionary tree representing proximity relationships between species. This motivates the notion of leaf powers: a graph G = (V, E) is a leaf power if there exist a tree T on leafset V and a threshold k such that uv is an edge if and only if the distance between u and v in T is at most k. Characterizing leaf powers is a challenging open problem, along with determining the complexity of their recognition. This is in part due to the fact that few graphs are known to not be leaf powers, as such graphs are difficult to construct. Recently, Nevries and Rosenke asked if leaf powers could be characterized by strong chordality and a finite set of forbidden subgraphs. In this paper, we provide a negative answer to this question, by exhibiting an infinite family \G of (minimal) strongly chordal graphs that are not leaf powers. During the process, we establish a connection between leaf powers, alternating cycles and quartet compatibility. We also show that deciding if a chordal graph is \G-free is NP-complete, which may provide insight on the complexity of the leaf power recognition problem

Performance Analysis of On-Line Camera-Based Web Inspection Sensors: A Pilot-Scale Experimental Study

Camera-based web inspection sensors have been available in the paper industry for many years. However, in recent years because of a market demand for high-quality paper products, the need for realtime flaw-detection systems has increased significantly. In addition to flaw-detection capabilities, these systems should be capable of doing defect classification (e.g., relative to size and type of flaws) as well as defect localization (providing information on location of flaws). The technique employed in flaw detection and measurement principles used in common systems are based on laser, CCD (charge coupled device) camera, or infrared technology. The study was designed to determine the capabilities of commercially available CCD camerabased systems. A CCD camera-based commercial sensor was installed on a pilot paper coater machine with the production speed capability of 1524 m/min (5000 ft/min) that could accept paper rolls with a width of 76.2 cm (30 inches). Various paper grades consisting of newsprint, coated paper, coated board, and linerboard which had typical grade-related defects were provided by various paper mills for testing. The purpose of this manuscript is to describe the operational principle, capabilities, and performance of various sensors used in paper industry in detecting various flaws and defects and to provide a summary of the results obtained using a commercial sensor

Physical oceanographic investigations in the Eastern Bering and Chukchi Seas during the summer of 1947

New information on the physical properties of the waters in the eastern Bering and Chukchi seas is discussed. It shows that, in summer, the water masses of this area are complicated by the circulation and advective processes. In general, the southern Bering Sea water flows northward and is modified by warm low-salinity water from rivers along the Alaskan coast and from intrusions of cold high-salinity water from the western Bering Sea. This mixture of water funn els through the Bering Strait principally at the surface on the eastern side...

Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius

We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as due to the presence of a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods. We use CoRoT color information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive optics imaging, near-infrared spectroscopy and preliminary results from Radial Velocity measurements, to test the diluted eclipsing binary scenarios. The parameters of the host star are derived from optical spectra, which were then combined with the CoRoT light curve to derive parameters of the companion. We examine carefully all conceivable cases of false positives, and all tests performed support the planetary hypothesis. Blends with separation larger than 0.40 arcsec or triple systems are almost excluded with a 8 10-4 risk left. We conclude that, as far as we have been exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which we derive a period of 0.853 59 +/- 3 10-5 day and a radius of Rp = 1.68 +/- 0.09 REarth. Analysis of preliminary radial velocity data yields an upper limit of 21 MEarth for the companion mass, supporting the finding. CoRoT-7b is very likely the first Super-Earth with a measured radius.Comment: Accepted in Astronomy and Astrophysics; typos and language corrections; version sent to the printer w few upgrade

The effect of nitrogen fertilization and no-till duration on soil nitrogen availability and greenhouse gas emissions

Non-Peer ReviewedWith a world population now greater than seven billion, it is imperative to conserve the arable land base, which is increasingly being leveraged by global demands for producing food, feed, fibre, and fuel. A key component of sustainable agriculture involves the restoration of unproductive lands that have been rendered unsuitable for agricultural production through anthropogenic soil degradation. The objective of this study was to determine the effect of varying fertilizer N rates on soil N availability and N2O and CO2 emissions of three soils collected at adjacent locations with contrasting management histories: native prairie or short-term (10 years) and long-term (32 years) no-till continuous multi-crop (wheat-pea-canola) cropping systems receiving five fertilizer N rates (0, 30, 60, 90, and 120 kg N/ha) for the previous nine years. Intact soil cores were collected from each site, maintained at field capacity, and incubated (22 oC) for six weeks. Weekly assessments of soil nutrient availability and N2O and CO2 emissions were completed to assess the impact of prolonged variable rates of fertilizer N and duration of no-till management of degraded agricultural soil relative to an adjacent native prairie soil. At the end of the six-week incubation, there was no significant difference (P > 0.15) in cumulative soil N supply rate between the unfertilized long-term no-till soil and native soil. Annual fertilizer N additions of 120 kg N/ha for the previous nine years were required to restore the N supplying power of the short-term no-till soil to that of the native soil, through the build-up of mineralizable N levels. As expected, repeated applications of fertilizer N increased the residual soil N levels in the cultivated soils compared to the native soil. The estimated cumulative CO2-C and N2O-N emissions at the end of the six-week incubation ranged from 231.8-474.7 g/m2 to 183.9-862.5 mg/m2, respectively. Repeated applications of ≥ 60 kg N/ha supported larger N2O-N fluxes in the long-term no-till soil compared to the unfertilized control. Highest CO2-C fluxes from the native prairie soil are consistent with its high organic matter content and contributions from root respiration. Surprisingly, the native prairie soil N2O-N emissions were equal to those from LTNT and STNT soils receiving repeated fertilizer N applications at typical agronomic rates and is probably characteristic of rapid denitrification rates during the dormant vegetative period after snow melt prior to the growing season within temperate native grassland environments. The use of modern no-till continuous multi-crop cropping systems, along with application of fertilizer N, enhances the soil N supplying power over the long-term through the build-up of mineralizable N and appears to be an effective management strategy for improving degraded soils, thus enhancing the productive capacity of agricultural ecosystems. However, accounting for N2O emissions associated with repeated fertilizer N applications is imperative for properly assessing the net global warming potential of any land management system

Beyond representing orthology relations by trees

Reconstructing the evolutionary past of a family of genes is an important aspect of many genomic studies. To help with this, simple relations on a set of sequences called orthology relations may be employed. In addition to being interesting from a practical point of view they are also attractive from a theoretical perspective in that e.\,g.\,a characterization is known for when such a relation is representable by a certain type of phylogenetic tree. For an orthology relation inferred from real biological data it is however generally too much to hope for that it satisfies that characterization. Rather than trying to correct the data in some way or another which has its own drawbacks, as an alternative, we propose to represent an orthology relation $\delta$ in terms of a structure more general than a phylogenetic tree called a phylogenetic network. To compute such a network in the form of a level-1 representation for $\delta$, we formalize an orthology relation in terms of the novel concept of a symbolic 3- dissimilarity which is motivated by the biological concept of a ``cluster of orthologous groups'', or COG for short. For such maps which assign symbols rather that real values to elements, we introduce the novel {\sc Network-Popping} algorithm which has several attractive properties. In addition, we characterize an orthology relation $\delta$ on some set $X$ that has a level-1 representation in terms of eight natural properties for $\delta$ as well as in terms of level-1 representations of orthology relations on certain subsets of $X$