Supplier selection under risk of delivery failure: a decision-support model considering managers’ risk sensitivity

This paper studies the problem of supplier selection and order allocation in a retail supply chain (comprising suppliers, a central purchasing unit and outlets) under disruption risk. The final demand is deterministic. Suppliers are located in different geographic areas, and supplies are subject to a positive probability of disruption. Different capacity and failure probabilities for each supplier are considered. Our analysis focuses on the insurance versus profitability trade-off faced by a supply manager who buys from suppliers for the outlets. Instead of determining optimal decisions given an objective function and the risk sensitivity of the decision-maker, we use a mixed integer linear programming approach to provide decision-making support that shows a supply manager the ‘elasticity of (expected) losses versus (expected) profits’. Under this model, and depending on the profit-and-loss targets, a supply manager of known risk sensitivity (i.e. risk aversion and loss aversion) can make better decisions when choosing suppliers. Moreover, taking into account, the impact of the share of fixed costs that must be covered by the operation, we consider the net values of expected profit and loss. We discuss the potential influence of the level of the firm’s fixed costs on the supply strategy. In particular, we show how the minimum value of the gross margin needed for the strategy’s profitability affects that strategy. A numerical application is conducted to illustrate the contribution of our decision-making support mechanism, and several managerial insights are obtained.     

Iron(III) and Cobalt(III) Complexes with Oxalate and Phenanthroline: Synthesis,Crystal Structure,Spectroscopy Properties and Magnetic Properties

We report herein the synthesis and physicochemical characterization of two mixed-ligand complexes of the following stoichiometric formulae: [Fe(phen)₂(ox)](NO₃)?2H₂O (1) and [Co(phen)₂(ox)](NO₃)?4H₂O (2) (as phen: 1,10-orthophenanthroline; ox: oxalate dianion). Both compounds have been prepared by slow evaporation at room temperature and characterized by single-crystal X-ray diffraction. They have been characterized by IR and UV–Vis spectra and thermoanalysis (TG and DTA) The structures of these compounds are highly symmetric. Indeed, the two compounds are isomorphous and crystallize in the orthorhombic space group Ibca. In each material, the M^III ion has a slightly distorted square bipyramidal environment, coordinated by one oxalate ion and two 1,10-orthophenanthroline ligands. Structural cohesion is established essentially by π–π interactions between the rings of phen groups and intermolecular O–H…O hydrogen bonds connecting the ionic entities and uncoordinated water molecules. Magnetic susceptibility measurements of (1) in the range 5–300 K exhibit paramagnetic behavior at high temperature. However, at low temperature, the magnetic data show the occurrence of weak antiferromagnetic intermolecular interactions between the local spins.     

Transportation ontology definition and application for the content personalization of user interfaces

Ontologies have been largely exploited in many domains and studies. In this paper, we present a new application of a domain ontology for generating personalized user interfaces for transportation interactive systems. The concepts, relationships and axioms of transportation ontology are exploited during the semi-automatic generation of personalized user interfaces. Personalization deals with the capacity of adaptation of a user interface, reflecting what is known about the user and the domain application. It can be performed on the interface container presentation (e.g., layout, colors, sizes) and in the content provided in their input/output (e.g., data, information, document). In this paper, the transportation ontology is used to provide the content personalization. This paper presents the ontology and how it is used for the personalization of user interfaces for developing transportation interactive systems by model-driven engineering.     

A new non-overlapping block processing technique for realizing linear phase two-pass recursive digital filters

A technique is presented to realize recursive digital filters with a linear phase and arbitrary magnitude characteristics. It is based on a well-known non-causal two-pass forward/backward filtering; where, a non-overlapping segmentwise processing is involved for a real-time implementation. Initial conditions of the backward pass are calculated recursively instead of a direct computation in the previous Arias-de-Reyna and Acha?s non-overlapping method. Additionally, a single first in, first out memory (FIFO) is introduced to organize samples into a data queue structure, and it allows filtering in real-time sample-by-sample. These improvements over the prior non-overlapping method can reduce delays and data storage capacities, and get similar computational complexity and phase linearity precision in passband.We show through the proposed non-overlapping technique that the forward/backward scheme can be a good alternative and competitive over the Powell and Chau?s backward/forward realization. We get better data storage capacities and phase linearity precision in passband, with approximately the same delays. Simulation of group delay precision in agreement with our contributions is illustrated.     

OS-CFAR and CMLD threshold optimization in distributed systems using evolutionary strategies

This paper proposes an improvement of the threshold optimization in distributed ordered statistics constant false alarm rate and censored mean level detector using Evolutionary Strategies (ESs). The target is assumed to be Rayleigh distributed and the observations are independent from sensor to sensor. Two fusion rules; “AND” and “OR” were considered. An ES was tested and a comparison with a genetic algorithm improved by a tournament selection was also analyzed. Among a variety of evolution strategies, the most popular proposed in the literature are the strategy (μ, λ) and the strategy (μ + λ). We proposed an (μ + λ) evolution strategy, by which a self-adaptation mutation is used. The results showed that, although the ES is more difficult to implement and is in a certain manner slower than the GA, it improves the performance of the system.     

Induction machine fault detection using stray flux EMF measurement and neural network-based decision

The aim of this paper is to present the performances of voltage unbalance and rotor fault detections using an external stray flux sensor in a working three-phase induction machine. The automatic classification and fault severity degree evaluation are realized by using a neural network approach based on a multi-layer perceptron (MLP) structure. In this paper, it is proved that a simple external stray flux sensor is more efficient than the classical stator current sensor to detect rotor broken bar and voltage unbalance, using data processing at low-frequency resolution.     

α-Tocopherol and fatty acids contents of some Tunisian table olives (Olea europea L.): Changes in their composition during ripening and processing

An experimental investigation was carried out on Tunisian olive-fruits of Meski, Sayali and Picholine cultivars. α-Tocopherol and fatty acids (FA) contents were analyzed, during both ripening and processing, according to the Spanish style. The relationship between oil, unsaponifiable and α-tocopherol contents was determined only during ripening. A genetic effect on FA composition was observed throughout the sampling periods. The highest oleic acid content was found in Sayali cultivar at green stage (78.5% of total FA). α-Tocopherol was positively correlated with unsaturated FA content (R = 0.71, p < 0.05), and oil amount (R = 0.984; R = 0.976; R = 0.952, p < 0.05 for Picholine, Sayali and Meski, respectively), but it was not correlated with unsaponifiable matter. In processed olive-fruits, the results showed primarily, that processing according to the Spanish style is not restricted to green olive-fruits but can be successfully used in cherry olives with guaranteed quality and nutritional value of processed product (Meski and Picholine) related to FA content. Secondly, both α-tocopherol and FA amounts decreased during processing for all cultivars. This decrease was cultivar dependent. It was more pronounced in the black fruit than in the green one for the same cultivar. During fermentation, pH variation showed the same profile in all cultivars. Final pH values at the end of fermentation depend on the concentration of free FA (acidity) in the brine.