3,845 research outputs found
A review of multi-criteria decision making methods for enhanced maintenance delivery
Conventionally there is a strong relation between manufacturing and services in complex engineering industries. For companies which aim to last in the competitive manufacturing market choosing appropriate decision making methods to improve their maintenance delivery has a vital role. The aim of this paper is to review Multi Criteria Decision Making (MCDM) models, evaluate each method and do a critical comparison to assess them from a maintenance management point of view. The first section of this paper reviews MCDM methods in different literature, and then the second part develops a set of criteria to classify different techniques. At the end methods are compared based on developed criteria. This paper assesses different MCDM models, and provides a framework to select approaches for maintenance management
A Survey on Fixed Divisors
In this article, we compile the work done by various mathematicians on the
topic of the fixed divisor of a polynomial. This article explains most of the
results concisely and is intended to be an exhaustive survey. We present the
results on fixed divisors in various algebraic settings as well as the
applications of fixed divisors to various algebraic and number theoretic
problems. The work is presented in an orderly fashion so as to start from the
simplest case of progressively leading up to the case of Dedekind
domains. We also ask a few open questions according to their context, which may
give impetus to the reader to work further in this direction. We describe
various bounds for fixed divisors as well as the connection of fixed divisors
with different notions in the ring of integer-valued polynomials. Finally, we
suggest how the generalization of the ring of integer-valued polynomials in the
case of the ring of matrices over (or Dedekind domain) could
lead to the generalization of fixed divisors in that setting.Comment: Accepted for publication in Confluentes Mathematic
Task Runtime Prediction in Scientific Workflows Using an Online Incremental Learning Approach
Many algorithms in workflow scheduling and resource provisioning rely on the
performance estimation of tasks to produce a scheduling plan. A profiler that
is capable of modeling the execution of tasks and predicting their runtime
accurately, therefore, becomes an essential part of any Workflow Management
System (WMS). With the emergence of multi-tenant Workflow as a Service (WaaS)
platforms that use clouds for deploying scientific workflows, task runtime
prediction becomes more challenging because it requires the processing of a
significant amount of data in a near real-time scenario while dealing with the
performance variability of cloud resources. Hence, relying on methods such as
profiling tasks' execution data using basic statistical description (e.g.,
mean, standard deviation) or batch offline regression techniques to estimate
the runtime may not be suitable for such environments. In this paper, we
propose an online incremental learning approach to predict the runtime of tasks
in scientific workflows in clouds. To improve the performance of the
predictions, we harness fine-grained resources monitoring data in the form of
time-series records of CPU utilization, memory usage, and I/O activities that
are reflecting the unique characteristics of a task's execution. We compare our
solution to a state-of-the-art approach that exploits the resources monitoring
data based on regression machine learning technique. From our experiments, the
proposed strategy improves the performance, in terms of the error, up to
29.89%, compared to the state-of-the-art solutions.Comment: Accepted for presentation at main conference track of 11th IEEE/ACM
International Conference on Utility and Cloud Computin
Novel Molecules for Intra-Oral Delivery of Antimicrobials to Prevent and Treat Oral Infectious Diseases
New molecules were designed for efficient intra-oral delivery of antimicrobials to prevent and treat oral infection. The salivary statherin fragment, which has high affinity for the tooth enamel, was used as a carrier peptide. This was linked through the side chain of the N-terminal residue to the C-terminus of a defensin-like 12-residue peptide to generate two bifunctional hybrid molecules, one with an ester linkage and the other with an anhydride bond between the carrier and the antimicrobial components. They were examined for their affinity to a HAP (hydroxyapatite) surface. The extent of the antimicrobial release in human whole saliva was determined using 13C-NMR spectroscopy. The candidacidal activity of the molecules was determined as a function of the antimicrobial release from the carrier peptide in human saliva. The hybrid-adsorbed HAP surface was examined against Candida albicans and Aggregatibacter actinomycetemcomitans using the fluorescence technique. The bifunctional molecules were tested on human erythrocytes, GECs (gingival epithelial cells) and GFCs (gingival fibroblast cells) for cytotoxicity. They were found to possess high affinity for the HAP mineral. In human whole saliva, a sustained antimicrobial release over a period of more than 40–60 h, and candidacidal activity consistent with the extent of hybrid dissociation were observed. Moreover, the bifunctional peptide-bound HAP surface was found to exhibit antimicrobial activity when suspended in clarified human saliva. The hybrid peptides did not show any toxic influence on human erythrocytes, GECs and GFCs. These novel hybrids could be safely used to deliver therapeutic agents intra-orally for the treatment and prevention of oral infectious diseases
HET acid based oligoesters – TGA/FTIR studies
One of the important reactive halogenated dicarboxylic acids used in the synthesis of flame retardant unsaturated polyester resins is 1,4,5,6,7,7-hexachlorobicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid (HET acid). In the present investigation four different oligoesters are synthesized using HET acid as the diacid component and 1,2-ethane diol, 1,2-propane diol, 1,3-propane diol and 1,4-butane diol as the aliphatic diols. Melt condensation technique in vacuum is used for the synthesis of the oligoesters. The number average molecular weights of the oligoesters are determined using end group analysis. The degree of polymerization is estimated to be 3–5. The structural characterization is done using FTIR and NMR (1H and 13C) techniques. In the present investigation, TGA-FTIR studies for the different oligoesters are carried out in nitrogen atmosphere. The materials are heated from ambient to 600 °C at a heating rate of 20 °C/min. The main volatile products identified are CO, HCl, H2O, CO2, hexachlorocyclopentadiene and HET acid/anhydride. The evolution profile of these materials with respect to the structure of the oligoesters is discussed in detail and presented. The importance of β-hydrogens in the diol component and the plausible mechanism for the flame retardant behavior of these oligoesters are presented
Resistivity and Thermopower of Ni2.19Mn0.81Ga
In this paper, we report results of the first studies on the thermoelectric
power (TEP) of the magnetic heusler alloy NiMnGa. We explain
the observed temperature dependence of the TEP in terms of the crystal field
(CF) splitting and compare the observed behavior to that of the stoichiometric
system NiMnGa. The resistivity as a function of temperature of the two
systems serves to define the structural transition temperature, T, which is
the transition from the high temperature austenitic phase to low temperatures
the martensitic phase. Occurrence of magnetic (Curie-Weiss) and the martensitic
transition at almost the same temperature in NiMnGa has been
explained from TEP to be due to changes in the density of states (DOS) at the
Fermi level.Comment: 12 pages, 4 figures, Accepted in Physical Review B vol 70, Issue 1
A Study on Android Application Development
As and when the world moves towards the hand-held devices, there should be an innovation as well as awareness of such kind of application development used for the hand-held device. As time elapses the world started moves on the fingers using such kind of developed applications. In this paper we discuss the most fundamental attributes and crucial steps followed to create a robust application using Android OS. This kind of contribution will help a lot to the initiators who want to switch-over from other technologies to the mobile application development
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