-
[show abstract]
[hide abstract]
ABSTRACT: One of the steps in a reverse supply chain is to disassemble the recovered products. The design of such disassembly operations
is more complex than that of classical assembly lines. A new GRASP algorithm is presented in this paper for solving Disassembly
Sequence Planning, i.e. the determination of the sequence for disassembling component parts. The problem has a combinatorial
structure and a large number of constraints. Moreover, checking the feasibility of each solution element is time consuming.
The proposed approach is successfully tested against previous best known solutions for a set of public benchmark problems.
Operations Research-Spektrum 04/2012; 29(3):535-549. · 1.23 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The household appliance industry is one of the most important sectors from both the economic and environmental point of view. A greater understanding of the way in which consumers of these items behave would help to better plan the recycling needs as a function of previous purchase figures. This paper presents the findings of a field survey of Spanish consumer habits with respect to different common household appliances as regards replacement time and the reasons for replacing these appliances. The methodology used is based on survival analysis; specifically, a competing risks model. A Cox proportional hazards model is also used for the sake of comparison. Our results show that as the number of people and/or persons under 18 years in the household increases, the lifetimes of some types of appliance decrease significantly. Competing risk model shows that the probability of replacing the refrigerator due to malfunction and technological obsolescence increases with the increase of family members with a higher education. We also provide the cumulative incidence function for different appliances, which can be used to forecast future demands and electrical and electronic waste generation.
Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA. 06/2011; 29(6):622-33.
-
[show abstract]
[hide abstract]
ABSTRACT: From both the social as well as the economic perspective, the recycling of household waste products is of growing importance. The recycling of glass in particular is one of the most successful as far as public collaboration is concerned, as well as due to the demand for recycled material on the part of glass manufacturers. This article presents a model for designing the first stage in the reverse logistics chain, i.e. the collection of material (in our case, applying the model to the collection of glass) directly from the consumer by means of containers. The aim of this model is to determine how to distribute the recycling containers in a specific region in the most efficient way possible, taking into account the economic and sociological characteristics of the population (level of education, number of catering establishments, etc.), while attempting to maximise the material collected and reducing the logistics costs. The model has been applied to the case of the Principality of Asturias, Spain, obtaining estimations that improve the performance of the system.
Waste Management & Research 11/2002; 20(5):398-406. · 1.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The legal and social pressure to recycle materials is constantly on the increase. As a result of the physical characteristics of glass and its large-scale use, the glass-producing sector represents one of the most important in terms of volume when implementing reverse logistics practices. This article studies the relationships with suppliers and customers from the perspective of environmental demands on the part of the packaging and bottling companies that use this material. The study compares the results obtained in two European countries, Spain and Belgium, which present very different characteristics as regards consumer habits and recycling.
International Business Review. 15(5):527-546.
-
[show abstract]
[hide abstract]
ABSTRACT: As other metaheuristics, Scatter Search can gain from a parallel implementation. However, it is not clear beforehand which of the possible alternative parallelization strategies is more effective. To address this question, it has been selected as a test bed for empirical testing a classical combinatorial optimization problem, namely 0–1 knapsack problem, for which the sequential application of Scatter Search is well known. Two phases or groups of steps in the Scatter Search template have been identified as natural candidates for parallelization and several ways of carrying out that parallelization are proposed. An extensive experimental analysis involving 18 different parallel algorithms has been carried out testing the combinations of these alternative parallelization strategies on a battery of large random instances generated using a public code from the literature. The interpretation of the ANOVA results gives cues about the significance of the alternatives used in each phase and about the effect of the dynamic (vs. static) updating of the RefSet. A low average efficiency has been observed, although it has to be taken into account that, due to the termination condition used, not all algorithms tested carry out the same number of iterations.
European Journal of Operational Research.
