Search results for "Design of experiment"
showing 9 items of 49 documents
Impact of reverse logistics on supply chain performance
2013
Purpose – The purpose of this paper is to analyse the impact of reverse logistics on order and inventory variance amplification in a single-echelon supply chain (SC) and to propose a new order policy for dampening such amplification. Design/methodology/approach – A general review of the literature on sustainable operations and on the impact of reverse logistics on SC performance provides the foundation for the study. The authors use difference equation math approach for modelling and analysing a closed SC. A proper design of experiment and data collected from the European Union statistics validate the obtained numerical results. Findings – The variability of reverse flow in a closed loop S…
Experimental research regarding the study of surface quality of aluminum alloys processed through milling
2017
The aim of this paper is to present the necessary steps to conduct a design of experiment with application on the aluminum alloy surface quality obtained by end-milling process. The machined surface quality is influenced by the cutting process parameters, and especially by their variation. The research methods used in this paper are the Taguchi method - to determine the cutting parameters influence, on the surface quality, and the full factorial design of experiment to confirm the results obtained by Taguchi’s method and to determine the percentage of the parameters influence involved in the process.
Benefits of solvent concentration pulses in retention time modelling of liquid chromatography
2019
The advantages and disadvantages of the use of isocratic experimental designs including transient increments of organic solvent (i.e., pulses) in the mobile phase(s) of lowest elution strength are explored with modelling purposes. For retained solutes, this type of mixed design offers similar or better predictive capability than gradient designs, shorter measurement time than pure isocratic designs, and retention model parameters that agree with those derived from pure isocratic experiments, with similar uncertainties. The predicted retention times are comparable to those offered by models adjusted from pure isocratic designs, and the solvent waste is appreciably lower. Under a practical st…
Testing experimental designs in liquid chromatography (II): Influence of the design geometry on the prediction performance of retention models.
2021
Abstract In liquid chromatography, the reliability of predictions carried out with retention models depends critically on the quality of the training experimental design. The search of the best design is more complex when gradient runs are used instead of isocratic experiments. In Part I of this work (JCA 1624 (2020) 461180), a general methodology based on the error propagation theory was developed and validated for assessing the quality of training designs involving gradients. The treatment relates the mathematical properties of a retention model with the geometry of the training designs and their subsequent predictions. In that work, only five usual designs were considered. Part II invest…
Enhanced calculation of optimal gradient programs in reversed-phase liquid chromatography
2003
Abstract The resolution of a mixture of 16 β-blockers under gradient elution was optimised using both isocratic and gradient training sets, with a reversed-phase column and acetonitrile–water eluents. Error theory was applied to measure the information extracted from different gradient experimental designs. This allows checking the expected accuracy when gradient predictions exceed the initial solvent concentrations tested in the training set. This work applies the results on modelling found in a previous study [J. Chromatogr. A 1018 (2003) 169] where the performance of several retention models was compared. Enhanced retention predictions were applied to the optimisation of gradient program…
Testing experimental designs in liquid chromatography (I): Development and validation of a method for the comprehensive inspection of experimental de…
2020
The basis of interpretive optimisation in liquid chromatography is the prediction of resolution, from appropriate solute retention models. The reliability of the process depends critically on the quality of the experimental design. This work develops, validates and applies a general methodology aimed to evaluate the quality of any training experimental design, which will be applied in Part II to design optimisation. The methodology is based on the systematic evaluation of the uncertainties associated to the prediction of retention times in comprehensive scans of both isocratic and gradient experimental conditions. It is able to evaluate comprehensively experimental designs of arbitrary comp…
Design and experimental validation of a generic model for combinatorial assembly of DNA tiles into 1D-structures.
2010
Abstract Background Quantitative modeling of the self-assembly of DNA tiles leading either to defined end-products or distribution of biopolymers is of practical importance for biotechnology and synthetic biology. Methods The combinatorial process describing tile assembly was implemented into a generic algorithm allowing quantitative description of the population of significant species accumulating during the reaction course. Experimental formation and characterization by optical and electrophoresis approaches of copolymers resulting from the self-assembly of a limited number of half-complementary tiles were used to define and validate generic rules allowing definition of model parameters. …
Effets de quartier, effet de département : discrimination liée au lieu de résidence et accès à l'emploi
2013
L’objet de cette étude est de mesurer la discrimination à l’embauche à l’encontre des jeunes en Ile-de-France en raison du lieu de résidence en considérant plusieurs échelles spatiales de façon à distinguer l’effet de la réputation du département (Paris et la Seine-Saint-Denis), celui de la localité et celui du quartier. L’évaluation est réalisée sur données expérimentales auto-construites de testing selon un protocole permettant d’examiner les effets propres à chacune de ces trois échelles sur l’accès à l’emploi ainsi que leurs effets cumulés. On s’intéresse aux discriminations pour deux professions en tension du secteur de la restauration pour laquelle les discriminations devraient a prio…
Profit vs morality: how unfair is labor market discrimination? Results from a survey experiment
2019
Using an original survey-experimental protocol, we study the normative acceptability of the trade-off between immoral profit (discrimination) and costly morality (non-discrimination). We test the causal influence of three factors: i) the origin of discrimination, ii) the steepness of the morality/profit trade-off and iii) anti-discriminatory moral injunctions. Contrasting with past experimental and attitudinal studies, we find that a significant minority of respondents believe that labor market discrimination is acceptable when morality results in profit loss. We also find that the three tested factors have significant effects on normative opinions. Respondents are more likely to choose pro…