Owing to the wide range of trigeneration systems suitable for small-scale applications, the selection of the optimal system according to the end users' requirements and environmental conditions is crucial. The evaluation and comparison of possible alternatives of trigeneration systems are a multi-criteria decision problem because not only economic aspects must be considered but also technical, environmental and social aspects. This paper presents the case of selection of a trigeneration system for a typical residential building. Several kinds of trigeneration systems, whose dynamical sources are Stirling engines, micro-turbines, reciprocating engines and fuel cells, respectively, and a separate generation system are evaluated and compared in detail. As the evaluation criteria are a mixture of quantitative and qualitative criteria, quantitative multi-criteria methods are inadequate for handling this type of problems. Therefore a multi-criteria decision-making method, which combines the subjectivity of decision maker and the objectivity of numerical data, based on Fuzzy Set Theory and Analytic Hierarchy Process is proposed to solve this selection problem. Copyright © 2010 John Wiley & Sons, Ltd.

The main difference between the Last Planner production control system developed by Ballard and classical control systems is the way in which projects are controlled and planned. The Last Planner system focuses on controlling production units, workflows, and the quality of the performed work. It also permits the identification of the causes for the noncompletion of planned work and decision making in accordance with the project requirements so that actions are timely and productivity is increased. The objective of this paper is to present the results obtained from implementing the Last Planner system in the construction department of a chemical company. In this department, an information flow problem was detected among its members, in which supervisors lacked knowledge about the work to be performed until the project had been perfectly designed. This problem often led to long delays in the projects. The results from the Last Planner system implementation show that identifying the constraints of the planned work leads to an improvement in the percentage and quality of completed activities.

The main objective of this paper is the definition of a membership function assignment procedure based on inherent features of linguistic terms to determine their semantics when they are used for preference modelling. For this purpose, we consider what linguists say about concepts such as language complementarity, the influence of context, or the effects of the use of hedges (modifiers) on adverbs meaning. As a result, specificity, entropy and position in the universe of discourse of the functions assigned to each linguistic term are mainly determined by the intrinsic meaning of the hedges concerned. We uphold that the meaning of weakening hedges is linguistically non-inclusive because their semantics are subordinated to the proximity to the indifference meaning, whereas reinforcement hedges are linguistically inclusive. Consequently, the membership function assignment rules are different: fuzzy relational calculus and the horizon shifting model derived from the Alternative Set Theory are used to handle weakening and reinforcement hedges, respectively. The proposed elicitation method provides for the term set semantics, non-uniform distributions of non-symmetrical triangular fuzzy numbers, depending on the number of terms used and the character of the hedges involved. (This article belongs to the section “Information Theory, Probability and Statistics”).

The Spanish Ministry of Defense is currently attempting to reduce the amount of energy that is consumed by its military bases and has therefore raised concerns about how to make their facilities more energy efficient. To fulfill this objective, the Spanish army has developed various studies and projects, as well as a technical prescription sheet that defines the thermal transmittance values of the materials that are to be used to construct the different elements of the containers that make up the temporary housing units at Spanish military camps. Both governments and private entities have developed initiatives that are aimed at improving the energy efficiency of buildings, which are classified into two groups: those aimed at the development of mandatory building codes and those that are based on voluntary certification programs. The use of passive strategies is one of the key actions that is being implemented to achieve the NZEB category, as its first requirement is to be a “very low energy consumption building”. This paper compares the energy efficiency requirements of the tents and containers that are used in military camps and the energy-efficient design requirements that are demanded by the energy efficiency standards for buildings in the civil sector. Through this comparison, we determine how energy efficient the current living spaces in military camps are in order to define strategies that can be implemented to improve the design requirements of these living spaces so to reduce the consumption and operation logistics and to improve both operability and safety in military camp facilities.