DCAV: A software system to evaluate next-generation cloud data center availability through a friendly graphical interface

To assess the availability of different data center configurations, understand the main root causes of data center failures and represent its low-level details, such as subsystem's behavior and their interconnections, we have proposed, in previous works, a set of stochastic models to represent different data center architectures (considering three subsystems: power, cooling, and IT) based on the TIA-942 standard. In this paper, we propose the Data Center Availability (DCAV), a web-based software system to allow data center operators to evaluate the availability of their data center infrastructure through a friendly interface, without need of understanding the technical details of the stochastic models. DCAV offers an easy step-by-step interface to create and configure a data center model. The main goal of the DCAV system is to abstract low-level details and modeling complexities, becoming the data center availability analysis a simple and less time-consuming task.     

A new framework for metaheuristic-based frequent itemset mining

This paper proposes a novel framework for metaheuristic-based Frequent Itemset Mining (FIM), which considers intrinsic features of the FIM problem. The framework, called META-GD, can be used to steer any metaheuristics-based FIM approach. Without loss of generality, three metaheuristics are considered in this paper, namely the genetic algorithm (GA), particle swarm optimization (PSO), and bee swarm optimization (BSO). This allows to derive three approaches, named GA-GD, PSO-GD, and BSO-GD, respectively. An extensive experimental evaluation on medium and large database instances reveal that PSO-GD outperforms state-of-the-art metaheuristic-based approaches in terms of runtime and solution quality.     

Oxygen and Carbon Distribution in 80Kg Multicrystalline Silicon Ingot

Silicon - Multicrystalline silicon (mc-Si) wafers produced by directional solidification still dominate the world market, due to the factor quality/price. The performance of solar cell depends...     

New Bacteriocins from Lacticaseibacillus paracasei CNCM I-5369 Adsorbed on Alginate Nanoparticles Are Very Active against Escherichia coli

Lacticaseibacillus paracasei CNCM I-5369, formerly Lactobacillus paracasei CNCM I-5369, produces bacteriocins that are remarkably active against Gram-negative bacteria, among which is the Escherichia coli-carrying mcr-1 gene that is involved in resistance to colistin. These bacteriocins present in the culture supernatant of the producing strain were extracted and semi-purified. The fraction containing these active bacteriocins was designated as E20. Further, E20 was loaded onto alginate nanoparticles (Alg NPs), leading to a highly active nano-antibiotics formulation named hereafter Alg NPs/E20. The amount of E20 adsorbed on the alginate nanoparticles was 12 wt.%, according to high-performance liquid chromatography (HPLC) analysis. The minimal inhibitory concentration (MIC) values obtained with E20 ranged from 250 to 2000 μg/mL, whilst those recorded for Alg NPs/E20 were comprised between 2 and 4 μg/mL, which allowed them to gain up to 500-fold in the anti-E. coli activity. The damages caused by E20 and/or Alg NPs/E20 on the cytology of the target bacteria were characterized by transmission electron microscopy (TEM) imaging and the quantification of intracellular proteins released following treatment of the target bacteria with these antimicrobials. Thus, loading these bacteriocins on Alg NPs appeared to improve their activity, and the resulting nano-antibiotics stand as a promising drug delivery system.     

BOD‐LEACH: broadcasting over duty‐cycled radio using LEACH clustering for delay/power efficient dissimilation in wireless sensor networks

Broadcasting delay‐sensitive information over a duty‐cycled wireless sensor network is considered, and a cluster‐based protocol is proposed. The proposed protocol, namely Broadcast over Duty‐Cycle and LEACH (BOD‐LEACH), takes advantage of the LEACH's energy‐efficient clustering. This approach shifts the total burden of energy consumption of a single cluster head by rotating the cluster‐head role among all nodes in the network. It also permits the ordinary (member) nodes in a cluster to turn off their radios whenever they enter inactive TDMA slots. However, LEACH does not consider broadcast messages, and the member nodes scheduling is established as a sequence of Time Division Multiple Access (TDMA) without any common active period. A broadcast message should then be postponed to the next TDMA schedule and transmitted in a sequence of unicast messages, which is inefficient in terms of latency, bandwidth occupation, and power consumption. The proposed protocol adds new common static and dynamic broadcast periods to support and accelerate broadcasting. The dynamic periods are scheduled following the past arrivals of messages and using a Markov chain model. To our knowledge, this work is the first that proposes the use of clustering to perform simultaneous local broadcasts at several clusters. This reduces broadcast latency and ensures scalability. The protocol has been simulated, numerically analyzed, and compared with LEACH. The results show clear improvement over LEACH with regard to broadcast latency, at a low energy cost. Copyright © 2013 John Wiley & Sons, Ltd.     

Experimental and theoretical study of Parabolic trough collector (PTC) with a flat glass cover in the region of algerian sahara (Ouargla)

Journal of Mechanical Science and Technology - In the present work, an experimental study has been performed at Ouargla in the south of Algeria to determinate the outlet water temperature and...     

A new enhanced assumed strain quadrilateral membrane element with drilling degree of freedom and modified shape functions

A new four‐node quadrilateral membrane finite element with drilling rotational degree of freedom based on the enhanced assumed strain formulation is presented. A simple formulation is achieved by five incompatible modes that are added to the Allman‐type interpolation. Furthermore, modified shape functions are used to improve the behaviour of distorted elements. Numerical results show that the proposed new element exhibits good numerical accuracy and improved performance, and in many cases, superior to existing elements. In particular, Poisson's locking in nearly incompressible elasticity fades and the element performs well when it becomes considerably distorted even when it takes almost triangular shape. Copyright © 2016 John Wiley & Sons, Ltd.     

Comments on “A General Model of Multipath Error for Coherently Tracked BOC Modulated Signals”

The mathematical formulation of the discriminator and the multipath error models presented by Harris and Lightsey contains some typing errors. In this comment, we review the formalism of aforementioned models and we fix and correct these typing errors. The simulation results show that the original analytical models, with these corrections, coincide with the numerical models.