Adaptive Transactional Memories: Performance and Energy Consumption Tradeoffs

Energy efficiency is becoming a pressing issue, especially in large data centers where it entails, at the same time, a non-negligible management cost, an enhancement of hardware fault probability, and a significant environmental footprint. In this paper, we study how Software Transactional Memories (STM) can provide benefits on both power saving and the overall applications’ execution performance. This is related to the fact that encapsulating shared-data accesses within transactions gives the freedom to the STM middleware to both ensure consistency and reduce the actual data contention, the latter having been shown to affect the overall power needed to complete the application’s execution. We have selected a set of self-adaptive extensions to existing STM middlewares (namely, TinySTM and R-STM) to prove how self-adapting computation can capture the actual degree of parallelism and/or logical contention on shared data in a better way, enhancing even more the intrinsic benefits provided by STM. Of course, this benefit comes at a cost, which is the actual execution time required by the proposed approaches to precisely tune the execution parameters for reducing power consumption and enhancing execution performance. Nevertheless, the results hereby provided show that adaptivity is a strictly necessary requirement to reduce energy consumption in STM systems: Without it, it is not possible to reach any acceptable level of energy efficiency at all

Dispersion of nickel and molybdenum from mineralisation in glaciated terrain, S. Norway

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New data on eudialyte decomposition minerals from kakortokites and associated pegmatites of the Ilimaussaq complex, South Greenland

A suite of samples with eudialyte and eudialyte decomposition minerals from the kakortokite and associated pegmatites of the Ilimaussaq complex in South Greenland has been investigated by electron microprobe analysis. Extensive decomposition of eudialyte has resulted in the formation of catapleiite as host for a number of rare and hitherto unknown REE minerals besides known minerals such as monazite and kainosite. Mineral A1 is present in very small amounts in nearly all eudialyte decomposition aggregates and comprises two varieties: Ca-rich A1 with composition HCa3REE6(SiO4)6(Fsquare) and presumed apatite structure, and Ca-poor A1 with composition (Fe,Mn,Ca)1.5REE6Si6FO22 and unknown structure. Mineral A2 with composition (Ca,Fe)1.2 REE4Si6O19-y(OH)2y.nH2O is indistinguishable from A1 in EMP-backscattered light and has only been found at a limited number of localities. Mineral A2 also occurs as a primary mineral at one locality. Additional rare and new REE-minerals are mineral A3 with composition Na0.2Ca0.6Fe0.2Mn0.5Al0.5REE2.8Si6F0.5O)18-y(OH)2y . nH2O; mineral Uk2 with composition REE2.00F1.50O2.25-y(OH)2y . nH2O; mineral Uk3 with composition CaREE4O7-yOH)2y . nH2O; and mineral Y1 with composition Na2Ca4Y2.7REE1.3F18 (OH)4. The Ce:(Y+La+Pr+Nd+Sm+Gd) molar ratio for A1, A2, A3, Uk2, Uk3 and monazite is close to 1:1. Characteristic for A1, A2 and monazite are substantial solid solutions between La and (Pr+Nd+Sm+Gd) with slowly increasing content of Ce as the content of La increases. A similar pattern does not exist for the REE in fresh eudialyte. Kainosite, identified in one decomposition aggregate, has not previously been found in the Il maussaq complex.</p

The geochemistry, kinematics and geodynamics of the Gannakouriep dyke swarm

Bibliography: pages 106-110.The Gannakouriep dyke swarm comprises a linear swarm of north to northeast striking mafic dykes emplaced during late Proterozoic rifting in the Gariep belt. The swarm has a strike length of over 300 km crossing terrane boundaries of the Gordonia sub-province, Richtersveld igneous sub-province and 8 ushmanland sub-province of the Namaqua Mobile Province. The main axis of dyke intrusion is centred within the 2.0 Ga Richtersveld igneous sub-province where the density of dyking increases westwards across strike towards the Gariep belt, prior to disappearing within the sediment/basement contact of the para-autochthonous Port Nolloth Assemblage. An internal Rb-Sr mineral isochron, together with pyroxene K-Ar plateau and whole rock model TCHUR ages, indicate that the dyke swarm was intruded around 720 Ma. The majority of the dykes comprise subophitic relict gabbros and dolerites of alkali affinities replaced by metamorphic minerals of both greenschist and amphibolite facies. The greenstones are encountered within the NE striking eastern sector of the dyke swarm which records the original tensile stress field, whilst amphibolites are encountered in the northerly striking western sector of the swarm which has been rotated 26° anticlockwise during Pan-African (500-550 Ma) deformation in the Gariep belt. The latter age of regional metamorphism and deformation is supported by available K-Ar age data on whole rock samples and amphibole mineral separates. Integrated field relationships, continuum mechanics modelling and geochemical studies suggest that the swarm was initiated as a series of low level crustal magma chambers which subsequently gave rise to a series of dyke complexes that comprise the Gannakouriep dyke swarm. The geochemical variability between individual dyke complexes across the entire swarm is negligible; only slight differences being recorded by their high-field-strength element concentrations. The latter suggests that all dykes are genetically linked to a single mantle diapir, with only slight source characteristic heterogeneities. All dykes are ferro-tholeiites with no primitive (picritic) member being present. Geochemical trends recorded by the swarm are easily reconcilable in terms of fractionation of the phenocryst assemblage olivine, plagioclase, clinopyroxene, (ilmenite and Ti-magnetite). However an earlier phase of fractionation of essentially olivine and plagioclase at the base of the crust is suggested since constraints on the degree of partial melting (3-6%) imposed by REE patterns would derive an alkali basalt parental melt. The geodynamic relationship between the Gannakouriep dyke swarm and rifting in the Gariep belt is accounted for by a lithospheric plate model containing non-coincidental crustal and mantle weaknesses represented by late Namaquan D4n extensional faults and a mantle weakness possibly resulting from crustal thickening within the Richtersveld igneous sub-province during Namaquan tectonics

A graph oriented approach for network forensic analysis

Network forensic analysis is a process that analyzes intrusion evidence captured from networked environment to identify suspicious entities and stepwise actions in an attack scenario. Unfortunately, the overwhelming amount and low quality of output from security sensors make it difficult for analysts to obtain a succinct high-level view of complex multi-stage intrusions. This dissertation presents a novel graph based network forensic analysis system. The evidence graph model provides an intuitive representation of collected evidence as well as the foundation for forensic analysis. Based on the evidence graph, we develop a set of analysis components in a hierarchical reasoning framework. Local reasoning utilizes fuzzy inference to infer the functional states of an host level entity from its local observations. Global reasoning performs graph structure analysis to identify the set of highly correlated hosts that belong to the coordinated attack scenario. In global reasoning, we apply spectral clustering and Pagerank methods for generic and targeted investigation respectively. An interactive hypothesis testing procedure is developed to identify hidden attackers from non-explicit-malicious evidence. Finally, we introduce the notion of target-oriented effective event sequence (TOEES) to semantically reconstruct stealthy attack scenarios with less dependency on ad-hoc expert knowledge. Well established computation methods used in our approach provide the scalability needed to perform post-incident analysis in large networks. We evaluate the techniques with a number of intrusion detection datasets and the experiment results show that our approach is effective in identifying complex multi-stage attacks

Diffusion-controlled and replacement microtextures in alkali feldspars from two pegmatites: Perth, Ontario and Keystone, South Dakota

Macro- and micro-perthitic microclines from pegmatites from Perth, Ontario (Wards catalogue 46 E 0510) and Keystone, South Dakota (Wards 46 E 5125) have been studied using light and electron microscopy. A sample of the type perthite from Perth, Ontario (Hunterian Museum, Glasgow, M2361) was compared using light microscopy. It differs in bulk composition and microtexture from the Wards sample. The Perth sample from Wards is a mesoperthite, with sub-periodic ~mm-thick albite veins near (100), with irregular surfaces. The microcline has regular tartan twins and formed from orthoclase by a continuous process. The Keystone sample is a microperthite, with non-periodic albite veins mainly in {110}. Irregular tartan twins, volumes of irregular microcline and subgrains suggest that the microcline formed by dissolution–reprecipitation. Microcline in both samples contains semicoherent cryptoperthitic albite films that formed after the development of tartan twins. The bulk compositions of these intergrowths imply exsolution below ~400°C. Diffusion parameters imply sustained heating for between 0.11 My at 400°C, 1.5 GPa and 8.4 My at 300°C, 1 GPa. Unrealistic times are required at 200°C. Subsequently, the crystals reacted with a fluid leading to replacive growth of the vein perthites. Unusually, Albite twin composition planes in replacive subgrains have sub-periodic dislocations, formed by coalescence of advancing growth twins. Processes that might lead to periodic, replacive intergrowths are discussed. The Perth and Keystone feldspars have been used for experimental work on dissolution during weathering and on anomalous thermoluminescence fading. Their microtextures make them unsuitable for obtaining properties that can be extrapolated to feldspars in general

Integration of magnetic residuals,derivates and located euler deconvolution for structural and geologic mapping of parts of the precambrian gneisses of Ago-Iwoye, Southwestern Nigeria

Ground based magnetic survey conducted between longitude 06O 55I 51IIN –06O 55I 54IIN and latitude 03O 52I 06IIE –03O 52I 4.8IIE (Olabisi Onabanjo University) remarkably revealed a consistent subsurface NW -SE structural azimuth of localized discontinuities within the shallowly buried heterogeneous basement rocks, which at exposed locations are composed of strongly foliated granite gneiss and migmatite-gneiss with veins and veinlets principally orientated in NNW –SSE direction.Magnetic survey of the area was preceded by site inspection to avoid metallic objects interferences. Field procedure in the area involved Cartesian gridding, base station establishment, data acquisition at gridded points, and repeated bihourly diurnal checksat the base station. At the processing stage, diurnal variation effect was aptly removed before subjection to Kriging (gridding). The gridded data was then prepared as input for Forward Fourier Filter Transform (FFT), which upon definition and implementation enabled Butterworth filtering of isolated ringing effects, reduction to the equator (RTE) for geomagnetic correction, and the use of Gaussian and Upward Continuation filtering for regional magnetic intensity trend determination. Removal of the regional magnetic intensity (RMI) from the total magnetic intensity (TMI) resulted in the derivation of the residual anomaly. Enhancement filters adopted for better resolution of the residual magnetic gradient include analytical signal (AS), tilt-angle derivative (TDR), vertical derivative deconvolution (VDD), and the first vertical derivatives (FVD).TMI and RMI values range between 32925nT –33050nT and 32935nT –333050nT respectively, while the residual gradient ranges between 15nT/m and10nT/m; AS ranges between 0.28nT/m and4.1nT/m; and TDR ranges from-1.4nT/m to 1.4nT/m. Source depth calculation estimated from power spectrum analysis and Euler deconvolution ranges between 1m and15m. Composite overlay of magnetic maps revealed jointed and faulted zones within the area; exhibiting a NW-SE principal azimuth of Liberian orogenic impress, which are in consistence with the foliation direction of the jagged foliated bedrock with an estimated maximum overburden of about 15m.The structural significance of this area as a prospective hydro-geological centre, and as an undesirable spot for high-rise building has been accurately evaluated from research findings. Application of integrated geophysical approach, complemented by detailed geological studies may furnish greater information about the subsurface structural architecture.Keywords:Gneisses; Ground Magnetic Surveying;RTE;Structural discontinuities;TDR.1INTRODUCTIONStructuralmapping is an integral part of geologic surveys. It involves measurements, analyses, interpretation and recognition of geometrical features (structures) generated by rock deformations [1]. These structures often serve as fountains of environmental challenges or unparalleled opportunities depending on their modesof occurrences, which in most cases are imminently controlled by the dynamic interplay of differential stress distributions within the earth interior. In line with the principle of uniformitarianism, a broad understanding about Earth’s paleo processes and internal workingsare deductible from the various deformation types for diverse applications. Deductible inferences from brittle deformationsinclude the kinematics of crustal blocks, orientation of principal axes of regional and local stresses, and geometry. Deeper insights indeep seated stresses, regional movements and block motions are obtainable from ductile deformations