Energy efficiency of dynamic management of virtual cluster with heterogeneous hardware

Cloud computing is an essential part of today’s computing world. Continuously increasing amount of computation with varying resource requirements is placed in large data centers. The variation among computing tasks, both in their resource requirements and time of processing, makes it possible to optimize the usage of physical hardware by applying cloud technologies. In this work, we develop a prototype system for load-based management of virtual machines in an OpenStack computing cluster. Our prototype is based on an idea of ‘packing’ idle virtual machines into special park servers optimized for this purpose. We evaluate the method by running real high-energy physics analysis software in an OpenStack test cluster and by simulating the same principle using the Cloudsim simulator software. The results show a clear improvement, 9–48 % , in the total energy efficiency when using our method together with resource overbooking and heterogeneous hardware.     

Specific heat of normal and superfluid3He

Extensive measurements of the heat capacity of liquid ³ He in the normal and superfluid phases are reported. The experiments range from 0.8 to 10 mK and cover pressures from 0 to 32.5 bar in zero magnetic field. The phase diagram of ³ He, based on the platinum NMR temperature scale, is presented. In the normal liquid at low pressures and near the superfluid transitionT _c an excess specific heat is found. The effective massm* of³He is at all pressures about 30% smaller than the values reported earlier. The calculated Fermi liquid parameters F₀ and F₁ are reduced asm*/m, while the spin alignment factor (1 + Z₀/4)^–1 is enhanced from 3.1–3.8 to 4.3–5.3, depending on pressure. The specific heat discontinuity C/C atT _c is forP = 0 close to the BCS value 1.43, whereas at 32.5 bar C/C is 1.90±0.03 in the B phase and 2.04±0.03 in the A phase, revealing distinctly the pressure dependence of strong coupling effects. The temperature dependence of the specific heat in the B phase agrees with a model calculation of Serene and Rainer. The latent heatL at the AB transition is 1.14±0.02 µJ/mole forP = 32.5 bar and decreases quickly as the polycritical point is approached; at 23.0 bar,L = 0.03 ± 0.02 µJ/mole.Work supported by the Academy of Finland.     

A MILP model for N-dimensional allocation

This paper presents a Mixed Integer Linear Programming (MILP) model for the solution of N-dimensional allocation problems. The applicability of the model is presented and demonstrated through some illustrative examples with different numbers of dimensions. Several problems, previously presented in the literature, are solved using the proposed model, such as, one-dimensional scheduling problems, two-dimensional cutting problems, as well as plant layout problems and three-dimensional packing problems. Additionally, some problems in four dimensions are presented and solved using the considered model. The presented model is applicable to a wide variety of allocation problems as it offers a general framework for modelling allocation problems with any given number of continuous or discrete dimensions. The presented problems are formulated as MILP problems where the first four dimensions usually are continuous spatial and time dimensions. Additional dimensions are often of a discrete nature.     

Structured but not over-structured: Woven active carbon fibre matt catalyst

Catalytic hydrogenation of citral was studied on a Pt on active carbon cloth (ACC) catalyst, with a Pd in ionic liquid on ACC and a commercial Pt on active carbon powder catalysts. The metal was supported on active carbon either by direct impregnation or utilizing the ionic liquid as the intermediate phase on the carbon. The influence on selectivity and activity, of the most important variables, such as temperature and pressure, was investigated in a batch reactor. Four consecutive experiments were carried out with each catalyst. The aim with the reuse of catalysts in the batch reactor was to elucidate eventual catalyst deactivation. The decrease in activity was very notable in the case of traditional impregnated catalysts, whereas the novel SSIL-TM (structured supported ionic liquid-transition metal) or Pd in ionic liquid on active carbon essentially maintained its activity in four consecutive batches. The catalysts were characterized with scanning electron microscopy, N₂ physisorption, and inductively coupled plasma analysis combined with mass spectroscopy. With the Pt on active carbon fibre catalyst, 80–100% selectivity of carbonyl group hydrogenation was achieved at 15% conversion, whereas the Pd in ionic liquid on ACC catalyst displayed an impressive metal efficiency (citral-to-Pd ratio of 156, mol:mol), selectivity (45%) and activity (92% conversion at 140 min) as well as tolerance towards catalyst deactivation. Supported ionic liquids provide a new reaction environment for catalytic transformations.     

Stereochemistry of the hydroperoxides formed during autoxidation of CLA methyl ester in the presence of α-tocopherol

The initial steps in the autoxidation of CLA methyl ester are poorly understood. The aim of this study was to determine the stereochemistry of the hydroperoxides formed during autoxidation of CLA methyl ester in the presence of a good hydrogen atom donor. For this purpose, 9-cis, 11-trans CLA methyl ester was autoxidized in the presence of α-tocopherol under atmospheric oxygen at 40°C in the dark. The CLA methyl ester hydroperoxides were isolated, reduced to the corresponding hydroxy derivatives, and separated by HPLC. The stereochemistry of seven hydroxy-CLA methyl esters was investigated. The position of the hydroxy group was determined by GC-MS. The geometry as well as the position of the double bonds in the alkyl chain was determined by NMR. In addition, the ¹³C NMR spectra of six hydroxy-CLA methyl esters were assigned using COSY, gradient heteronuclear multiple bond correlation, gradient heteronuclear single quantum correlation, and total correlation spectroscopy experiments. The autoxidation of 9-cis, 11-trans CLA methyl ester in the presence of a good hydrogen atom donor is stereoselective in favor of one geometric isomer, namely the 13-(R,S)-hydroperoxy-9-cis, 11-trans-octadecadienoic acid methyl ester. Three types of conjugated diene hydroperoxides are formed as primary hydroperoxides: trans,trans hydroperoxides (12-OOH-8t,10t and 9-OOH-10t,12t), a cis,trans hydroperoxide with the trans double bond adjacent to the hydroperoxide-bearing carbon atom (13-OOH-9c,11t), and a new type of cis,trans lipid hydroperoxide with the cis double bond adjacent to the hydroperoxide-bearing carbon atom (8-OOH-9c,11t). In addition, three nonkinetic hydroperoxides (13-OOH-9t,11t, 8-OOH-9t,11t, and 9-OOH-10t,12c) are formed. This study supports the theory that CLA methyl ester autoxidizes at least partly through an autocatalytic free radical reaction. The complexity of the hydroperoxide mixture is due to formation of two different pentadienyl radicals. Moreover, the stereoslectivity in favor of one geometric isomer can be explained by the selectivity of the two previous steps: the preferential formation of a W-conformer of the pentadienyl radical over the Z-conformer, and regioselectivity of the oxygen addition to the pentadienyl radical.     

Cu–H-MCM-41, H-MCM-41 and Na-MCM-41 Mesoporous Molecular Sieve Catalysts for Isomerization of 1-Butene to Isobutene

Cu–H-MCM-41, H-MCM-41 and Na-MCM-41 mesoporous molecular sieve catalysts were synthesized, characterized and investigated in the isomerization of 1-butene to isobutene. Introduction of copper in MCM-41 was found to play a positive role in enhancing the conversion of 1-butene and yield of isobutene and Cu–H-MCM-41 exhibited higher conversion of 1-butene and yield to isobutene than H-MCM-41 and Na-MCM-41 catalysts. The pretreatments of Cu–H-MCM-41 catalyst with synthetic air or hydrogen were observed to influence the 1-butene conversion, yield of isobutene and selectivity to isobutene. Pre-treated with the synthetic air the Cu–H-MCM-41-Ox catalyst exhibited higher conversion of 1-butene, yield of isobutene and selectivity to isobutene than hydrogen pre-treated Cu–H-MCM-41-Red. The reason for such a behavior of Cu–H-MCM-41-Red is the reduction of copper species to metallic form. The X-ray powder diffraction pattern of Cu–H-MCM-41-Red exhibited a peak attributed to the reduction of Cu²⁺ to Cu⁰. FTIR spectra of adsorbed pyridine showed the presence of Brønsted and Lewis acid sites in the H-MCM-41, Na-MCM-41 and Cu–H-MCM-41 catalysts.     

Building the essential resources for Finnish: the Turku Dependency Treebank

In this paper, we present the final version of a publicly available treebank of Finnish, the Turku Dependency Treebank. The treebank contains 204,399 tokens (15,126 sentences) from 10 different text sources and has been manually annotated in a Finnish-specific version of the well-known Stanford Dependency scheme. The morphological analyses of the treebank have been assigned using a novel machine learning method to disambiguate readings given by an existing tool. As the second main contribution, we present the first open source Finnish dependency parser, trained on the newly introduced treebank. The parser achieves a labeled attachment score of 81 %. The treebank data as well as the parsing pipeline are available under an open license at http://bionlp.utu.fi/.     

Contextual usage patterns in smartphone communication services

The mobile end user context has received a lot of attention from the mobile services industry lately. The location-based and context-sensitive information that are characteristic for smartphones can be utilized to study the use context of mobile end users. Accordingly, this article utilizes handset-based data in analyzing how the context of use affects the usage of smartphone communication services. The context is identified with an algorithm utilizing mobile network cell ID and WLAN data and resulting in five place-related contexts, namely Home, Office, Other meaningful, Elsewhere and Abroad. According to our analysis, voice calls are used least intensively in the Home context where the length of the voice calls is the longest, however. Email and SMS are used most intensively in the Office context, where the voice calls are the shortest in duration. Finally, mobile IM/VoIP and social media services are more free-time oriented as they are used most intensively in Elsewhere and Other meaningful contexts. The findings imply that people use smartphone communication services differently depending on the use context. However, context can be defined and identified in a number of ways, and this article presents only one solution that is highly dependent on the type of data collected.     

Effect of water and geological factors on the long-term stability of fracture zones in the Päijänne Tunnel, Finland: a case study

Potable water to the Helsinki metropolitan area in Finland is conveyed through Precambrian bedrock along the mostly unlined, rock-surfaced Päijänne Tunnel which has been in use since 1982. Two cave-ins in recent years and the damage observed during the inspection preceding the repair of the northern 64 km of the tunnel in 2001 demonstrates the active eroding processes. The extent of block falls inside the tunnel, interpreted from a recording made by a submersible robot, is compared with both measured and semi-quantitatively documented groundwater inflow and characteristics of fracture zones intersecting the tunnel that commonly appear as linear depressions in topography.Most of the damage observed in the tunnel is inferred to result from weathering, swelling clays, erosion and changes in groundwater or pressure conditions. The main factor in triggering these physical and chemical changes is water that flows both along the tunnel and in the fractures of the surrounding bedrock. Foliation sub-parallel to the tunnel orientation seems to be a factor making tunnel sections more prone to the occurrence of block falls.A high rate of groundwater inflow correlates to some degree with the level of original reinforcement. Even though groundwater inflow does not necessarily indicate support need, increased fracturing in bedrock generally provides more flow paths to water. Hydraulic properties of fracture zones are inferred to contribute to the deterioration in the tunnel but probably as a relatively minor factor compared with the rock support solutions and structural orientation sub-parallel to the tunnel. The orientation of fractures is inferred to play a role as variation is observed in inflow when linked with the strike of the fracture zone. The damage concentrates to zones of existing weakness and sections that have not been lined with shotcrete. Shotcrete prevents leaching of fracture fillings which can lead into loosening and falling of key-blocks. The application of steel-supported reinforcement in the fractured sections is a plausible explanation to why no consistent connection was observed between the occurrence of large block falls and fracture zone intersections. The impairment of the tunnel's condition, revealed during the repair inspection, is considered to have been influenced by the initially low level of reinforcement.