Dynamic replication factor model for Linux containers-based cloud systems

The Journal of Supercomputing - Infrastructure-as-a-service container-based virtualization is gaining interest as a platform for running distributed applications. With increasing scale of cloud...     

Experimental and numerical investigation of intermittent drying of timber

Intermittent drying may be of interest in the future to address energy issues. Such drying conditions are also likely to help stress relaxation through mechanosorptive creep. The influence of applying oscillations of temperature and relative humidity during the drying of beech timber on time and drying stresses is discussed in the paper by means of nonsymmetrical and loaded drying. Experimental data were used to validate a numerical model in the case of intermittent drying. The model was then used to perform a numerical investigation of the possibility of using an intermittent energy source to dry wood.     

A variable sampling interval Shewhart control chart for monitoring the coefficient of variation in short production runs

Monitoring the coefficient of variation (CV) allows process monitoring to be performed when both the process mean and the standard deviation are not constant but, nevertheless, proportional. Until now, few research papers have investigated the monitoring of the CV in a short production run context. This paper investigates the design and implementation of a Variable Sampling Interval Shewhart control chart to monitor the coefficient of variation in a short production run context. Formulas for the truncated average time to signal are derived and a performance comparison is carried out with a Fixed Sampling Rate Shewhart chart monitoring the CV. An example illustrates the use of this chart on real industrial data.     

Lattice vibrations of materials for lithium rechargeable batteries. VI: Ordered spinels

Raman scattering spectra have been investigated to evaluate the local structure of lithiated oxides used as electrode materials for lithium-ion batteries. We report the analysis of the vibrational spectra of ordered spinel phases including the partially delithiated λ-Li_0.5Mn₂O₄ ( SG), the partial charge-ordered LiMn₂O₄ orthorhombic form (Fddd SG) and the LiNi_0.5Mn_1.5O₄ substituted oxide (P4₁32 SG). Analysis of spectroscopic data is performed using the classical factor group theory and the vibration features are compared with those of the ordered lithium ferrite -LiFe₅O₈ and the normal spinels LiMn₂O₄ and LiNi_0.5Mn_1.5O₄ (Fd3m SG), and the inverse spinel LiNiVO₄.     

Adjustable audio watermarking algorithm based on DWPT and psychoacoustic modeling

This paper presents a novel adjustable audio watermarking method with high auditory quality by exploiting the discrete wavelet packet transform (DWPT), psychoacoustic modeling and distortion compensated-dither modulation (DC-DM) quantization. While the DWPT is used to divide the audio frames into several frequency sub-bands, the psychoacoustic model is intergraded to determine the appropriate sub-bands for watermarking and to control the number of embedded bits in each one. Then, the DC-DM technique is used to embed the watermark bits into the appropriate DWPT coefficients. The synchronization code technique is adopted in the proposed method to withstand desynchronization attacks. In order to achieve an adjustable watermarking scheme, two regulator parameters are provided to manage the capacity-robustness trade-off. The performance of the watermarking scheme is evaluated by examining different host audio signals under various watermarking attacks. The results show excellent imperceptibility of watermarked signals with an average ODG of ? 0.3. In addition, the proposed scheme provides strong robustness against the attacks with low capacity. However, high capacity (about 2500 bps) can be achieved while maintaining a reasonable robustness. A comparison with some state-of-the-art audio watermarking schemes reveals that the proposed method provides competitive results.     

Sparse Representations to Replace TOFD Images in Non-destructive Testing of Materials

This paper describes a proposed method for the selection of relevant samples of ultrasonic signals during automatic material inspection. Instead of the well-known time of flight diffraction (TOFD) images, data are stored as a sparse matrix in which the elements only indicate whether a defect has been detected. This technique avoids storage of useless signals received during probe displacement in cases of low and high signal-to-noise ratios that correspond to coarse-grained and fine-grained materials, respectively. The approach is based on comparing the positions of maximum amplitudes, which are randomly located when signals only consist of noise but are in the same signal range when a defect is detected. The matrix elements are then applied as inputs to a self organizing map by neural networks to produce a normalized sparse matrix as the output, with a constant number of elements. This approach will be beneficial to enable the use of selected data in intelligent systems requiring a fixed number of inputs to characterize defects.     

Identification of injection and extraction wells from overspecified boundary data

In this paper, we focus on the identification of wells’ positions and fluxes/flows from the knowledge of overspecified data: hydraulic head and flux, on a part of the domain boundary. The used method is based on minimizing a constitutive law gap functional. We consider two inverse problems: in the first one overspecified conditions are available throughout the entire domain boundary; in the second inverse problem, in addition to the wells, boundary condition are also unknown on an inaccessible part of the domain boundary.     

Changes on essential oil composition of coriander (Coriandrum sativum L.) fruits during three stages of maturity

The essential oils composition of coriander (Coriandrum sativum L.) fruits obtained by hydrodistillation was studied at three stages of maturity by GC–FID and GC–MS. Essential oil yields showed marked increase during maturation process and forty one compounds were identified. Geranyl acetate (46.27%), linalool (10.96%), nerol (1.53%) and neral (1.42%) were the main compounds at the first stage of maturity (immature fruits). At the middle stage, linalool (76.33%), cis-dihydrocarvone (3.21%) and geranyl acetate (2.85%) were reported as the main constituents. Essential oils at the final stage of maturity (mature fruits) consist mainly on linalool (87.54%) and cis-dihydrocarvone (2.36%). Additionally, accumulation of monoterpene alcohols and ketones was observed during maturation process of coriander fruit.     

Influence of the substitution of β-cyclodextrins by cationic groups on the complexation of organic anions

The inclusion complexation of the organic anion, dansyl-acid, by cationic derivatives of β-cyclodextrin has been investigated. A series of cationic β-cyclodextrins with various positive charge has been synthesized by selective functionalization of the primary face of β-cyclodextrin with amino groups. The complexes were of the 1:1 stoichiometry; the stability constants (K₁₁) have been evaluated from UV–Vis measurements by application of the Benesi–Hildebrand equation. The presence of amino groups increased the complexation ability. β-cyclodextrin fully substituted at the primary face with amino groups showed the strongest inclusion binding ability towards the dansyl-acid guest. The enhanced complexation for anions was ascribed to the cationic amino groups. A simple thermodynamic model of the electrostatic contribution to the complexation is presented.