A fuzzy AHP multi-criteria decision-making approach applied to combined cooling, heating and power production systems

Most of the real-world multi-criteria decision-making (MCDM) problems contain a mixture of quantitative and qualitative criteria; therefore quantitative MCDM methods are inadequate for handling this type of decision problems. In this paper, a MCDM method based on the Fuzzy Sets Theory and on the Analytic Hierarchy Process (AHP) is proposed. This method incorporates a number of perspectives on how to approach the fuzzy MCDM problem, as follows: (1) combining quantitative and qualitative criteria (2) expressing criteria pair-wise comparison in linguistic terms and performance of the alternative on each criterion in linguistic terms or exact values when criterion is qualitative or quantitative, respectively, (3) converting all the assessments into trapezoidal fuzzy numbers, (4) using the difference minimization method to calculate the local weight of criteria, employing the algebraic operations of fuzzy numbers based on the concept of α-cuts, (4) calculating the global weight of criteria and the global performance of each alternative using geometric mean and the weighted sum, respectively, (5) using the centroid method to rank the alternatives. Finally, an illustrative example on evaluation of several combined cooling, heat and power production systems is used to demonstrate the effectiveness of the proposed methodology

A fuzzy multi-criteria decision making model for construction contractor prequalification

Selecting an appropriate contractor is essential for the success of any construction project. Contractor prequalification procedure makes it possible to admit for tendering only competent contractor. Prequalification is a multi-criteria decision problem that is, in essence, largely dependent on the uncertainty and vagueness in the nature of construction projects and subjective judgement of the decision-maker. This paper presents a systematic prequalification procedure, based on Fuzzy Set Theory, whose main differences and advantages in comparison with other models are the use of an algorithm to handle the inconsistencies in the fuzzy preference relation when pair-wise comparison judgements are used and the use of linguistic assessment or exact assessment of performance of the contractors on qualitative or quantitative criterion, respectively. Finally, a case study for the rehabilitation project of a building at Technical University of Cartagena is presented to illustrate the use of the proposed model and to demonstrate its effectiveness

Last planner control system applied to a chemical plant construction

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 non-completion 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 meant long delays in the projects. The results from Last Planner system implementation show that identifying the constraints of the planned work leads to an improvement in the percentage and quality of completed activitie

A fuzzy approach to construction project risk assessment

The increasing complexity and dynamism of construction projects have imposed substantial uncertainties and subjectivities in the risk analysis process. Most of the real-world risk analysis problems contain a mixture of quantitative and qualitative data; therefore quantitative risk assessment techniques are inadequate for prioritizing risks. This article presents a risk assessment methodology based on the Fuzzy Sets Theory, which is an effective tool to deal with subjective judgement, and on the Analytic Hierarchy Process (AHP), which is used to structure a large number of risks. The proposed methodology incorporates knowledge and experience acquired from many experts, since they carry out the risks identification and their structuring, and also the subjective judgements of the parameters which are considered to assess the overall risk factor: risk impact, risk probability and risk discrimination. All of these factors are expressed by qualitative scales which are defined by trapezoidal fuzzy numbers to capture the vagueness in the linguistic variables. The most notable differences with other fuzzy risk assessment methods are the use of an algorithm to handle the inconsistencies in the fuzzy preference relation when pair-wise comparison judgements are necessary, and the use of trapezoidal fuzzy numbers until the defuzzification step. An illustrative example on risk assessment of a rehabilitation project of a building is used to demonstrate the proposed methodology

Methodology for designing non-permanent living spaces for different areas in Castilla y León

[SPA] Los criterios de diseño de espacios de vida temporales están afectados directamente por el tiempo de despliegue de la instalación y no siempre esto se tiene en cuenta. Las infraestructuras temporales desplegadas en el ámbito militares deben tener en cuento criterios económicos y de retorno de la inversión en función de la temporalidad de dicho espacio desplegado en una zona, de esta manera, se optimizará la inversión de los recursos y se reducirá tanto el consumo energético como el transporte logístico de combustible en la zona, lo que provocará una disminución en los convoyes logísticos y por lo tanto una mayor seguridad e independencia energética. Para dar solución al análisis de la temporalidad se ha generado una metodología para el diseño de los parámetros de diseño de las paredes de los espacios de vida temporales.[ENG] The design criteria for temporary living spaces are directly affected by the deployment time of the facility and this is not always taken into account. Temporary infrastructures deployed in the military field must take into account economic criteria and return on investment based on the temporality of the space deployed in an area, thus optimising the investment of resources and reducing both energy consumption and the logistical transport of fuel in the area, which will lead to a reduction in logistical convoys and therefore greater security and energy independence. In order to provide a solution to the temporality analysis, a methodology has been generated for the design of the design parameters of the walls of the temporary living spaces

Real time test benchmark design for photovoltaic grid connected control systems

This paper presents a dual digital signal processor (DSP) hardware architecture for a grid-connected photovoltaic interface test benchmark, based on a cascade DC/DC converter and DC/AC inverter, with coordinated control algorithms. The control hardware has been designed to test distributed generation (DG) interfaces to be integrated in a hierarchical structure of computational agents, to apply distributed control techniques to the power system management. The proposed dual DSP architecture enables the programming of the control software for the DC/DC converter and the DC/AC inverter in the same processor, to keep the other one for additional operations that are required when there is a high degree of interaction between the DG unit and the rest of the electrical grid components. The hardware architecture has been tested in several real situations such as power factor correction and anti-islanding protection

Sclerosing angiomatoid nodular transformation of the spleen: Case report

La transformación nodular angiomatoide esclerosante (SANT) es una rara patología vascular benigna primaria del bazo. La mayoría de personas son asintomáticos, constituyendo hallazgos incidentales en los estudios radiológicos. El diagnóstico definitivo es a través de la anatomopatología. La esplenectomía es el tratamiento de elección. Presentamos un caso de SANT que apareció como un hallazgo incidental de una masa esplénica al realizar una Tomografía computarizada.Sclerosing angiomatoid nodular transformation (SANT) is a rare primary benign vascular pathology of the spleen. Most people are asymptomatic, constituting incidental findings in radiological studies. The definitive diagnosis isthrough anatomopathology. Splenectomy is the treatment of choice

Strandings of cetaceans and sea turtles in the Alboran Sea and Strait of Gibraltar: a long-term glimpse at the north coast (Spain) and the south coast (Morocco)

., 2011. Strandings of cetaceans and sea turtles in the Alboran Sea and Strait of Gibraltar: a long-time glimpse of the north coast (Spain) and the south coast (Morocco). Animal Biodiversity and Conservation, 34.1: 151-163. Abstract Strandings of cetaceans and sea turtles in the Alboran Sea and Strait of Gibraltar: a long-term glimpse at the north coast (Spain) and the south coast (Morocco) .-A total of 13 species of cetaceans and three species of marine turtles were found in this study. Data were collected by eight independent and self-regulated stranding networks, providing information about 1,198 marine mammal (10 odontocetii, three mysticetii and one phocidae) and 574 sea turtle stranding events between 1991 and 2008. Trends in the strandings were analysed in relation to species composition and abundance, and their geographic and seasonal distribution. The most abundant species recorded were the striped dolphin and the loggerhead turtle. Some of the strandings, such as the humpback whale, harbour porpoise, hooded seal and olive ridley turtle, were considered 'rare' because their distribution did not match the pattern of the study. When the north and south coasts in the study area were compared, pilot whales stranded more frequently in the north, while delphinid species stranded more in the south coast, and loggerhead turtles stranded more frequently in the north while leatherback turtles stranded more in south coast. Key words: Strandings, South-western Mediterranean, Distribution, Marine turtle, Cetacean, Conservation. Resumen Varamientos de cetáceos y tortugas marinas en el mar de Alborán y el Estrecho de Gibraltar: un vistazo a largo plazo de la costa norte (España) y la costa sur (Marruecos) .-En este estudio se registraron un total de 13 especies de cetáceos y tres especies de tortugas marinas, proviniendo los datos de redes de voluntarios que prestan asistencia en los varamientos. Se recogió información de 1.198 mamiferos marinos (10 odontocetos, tres misticetos y un fócido) y 574 tortugas marinas entre los años 1991 y 2008. Se analizaron las tendencias de los varamientos en relación a la composición de especies, su abundancia y su distribución geográfica y estacional. Las especies más comunes fueron el delfín común y la tortuga boba. Algunos de los varamientos, como la ballena jorobada, la marsopa común, la foca de casco o la tortuga olivácea, pueden considerarse "anómalos" puesto que su distribución se escapa a los patrones del estudio. Comparando la costa norte del área de estudio con la sur, los calderones y tortugas bobas vararon con mayor frecuencia en la costa norte, mientras que las especies de delfines y las tortugas laúd vararon con mayor frecuencia en la costa sur

Manejo quirúrgico de perforación esofágica

Mujer de 42 años con diagnóstico de acalasia, admitida en la institución para dilatación neumática esofágica. En el procedimiento se evidencia a 20mm de la unión gastroesofágica diagnosticándose perforación esofágica una solución de continuidad de 25 mm. Se maneja con stent metálico autoexpandible totalmente cubierto, rafia del defecto vía laparoscópica y drenaje torácico, paciente pasa a Unidad de Cuidados Intensivos, presenta evolución favorable y obtiene su alta médica en el décimo día de hospitalización.A 42-year-old woman with a diagnosis of achalasia, admitted to the institution for esophageal pneumatic dilation. In the procedure, 20 mm from the gastroesophageal junction, a 25 mm continuity solution is evident, diagnosing esophageal perforation. She is managed with a fully covered self-expanding metal stent, laparoscopic defect raffia and thoracic drainage, the patient is transferred to the Intensive Care Unit, presents a favorable evolution and is discharged on the tenth day of hospitalization

Everolimus safety and efficacy for renal angiomyolipomas associated with tuberous sclerosis complex: A Spanish expanded access trial

Background: Renal angiomyolipomas (AML) are usual manifestations of tuberous sclerosis complex (TSC) that may cause aneurism-related haemorrhages and renal impairment. Everolimus has emerged as an alternative to surgery/embolization. We provide further insight into everolimus safety and efficacy for TSC-related AML. Methods: This was a Spanish expanded access trial including patients aged ≥18 years with TSC-related AML. They received 10 mg everolimus once daily until AML progression, unacceptable toxicity, death/withdrawal, commercialisation for TSC-related AML, or 1 year after first patient enrolment. The primary outcome was dose-limiting safety according to grade 3/4 adverse events, serious adverse events, or adverse events leading to treatment modification. Secondary outcomes included overall safety and efficacy. Results: Nineteen patients were enrolled and received everolimus for a median of 6.6 (5.3-10.9) months. Eleven (57.9 %) remained on 10 mg/day throughout the study and eight (42.1 %) required treatment modifications due to adverse events; none permanently discontinued treatment. Adverse events were overall grade 1/2 and most frequently included aphthous stomatitis/mucosal inflammation, hypercholesterolaemia/hypertriglyceridaemia, urinary tract infection, hypertension, dermatitis acneiform, and insomnia. Four (21.1 %) patients experienced grade 3 adverse events, none was grade 4, and only one (5.3 %) was serious (pneumonia). AML volume was reduced ≥30 % in 11 (57.9 %) patients and ≥50 % in 9 (47.4 %); none progressed. Right and left kidney sizes decreased in 16 and 14 patients, respectively. Conclusions: These findings support the benefit of everolimus for renal AML due to a manageable safety profile accompanied by reduced AML and kidney volumes. Trial registration: EudraCT number 2012-005397-63; date of registration 22 Nov 2012.This work was funded by Novartis Farmacéutica S.A., which was involved in study design, data analysis and interpretation, and writing of the manuscrip