Search results for " Opera"
showing 10 items of 3606 documents
Megabenthos Underwater Video (MUV): a new device to evaluate species distribution in hard-to-reach marine areas
2021
A device, called Megabenthos Underwater Video (MUV), was designed and built for the counting and the size estimate of benthic organisms in hard-to-reach areas. Since 2014 Cassiopea andromeda, an invasive alien jellyfish in the Mediterranean Sea with benthic behavior, colonized a recreational harbor (Cala) of Palermo with a stable population. Studying the species distribution in this area with classical methods (such as visual census, ROV, etc.) was not applicable due to the large presence of obstacles (ropes, anchor cables, boats) and to dive difficulties in these types of area. The MUV was tested from 2017 to 2018 for the study of the spatial-temporal distribution of C. andromeda in the Ca…
Scatter search for an uncapacitated p-hub median problem
2015
Scatter search is a population-based method that has been shown to yield high-quality outcomes for combinatorial optimization problems. It uses strategies for combining solution vectors that have proved effective in a variety of problem settings. In this paper, we present a scatter search implementation for an NP -hard variant of the classic p-hub median problem. Specifically, we tackle the uncapacitated r-allocation p-hub median problem, which consists of minimizing the cost of transporting the traffics between nodes of a network through special facilities that act as transshipment points. This problem has a significant number of applications in practice, such as the design of transportati…
A hybrid evolution strategy for the open vehicle routing problem
2010
This paper presents a hybrid evolution strategy (ES) for solving the open vehicle routing problem (OVRP), which is a well-known combinatorial optimization problem that addresses the service of a set of customers using a homogeneous fleet of non-depot returning capacitated vehicles. The objective is to minimize the fleet size and the distance traveled. The proposed solution method manipulates a population of @m individuals using a (@m+@l)-ES; at each generation, a new intermediate population of @l offspring is produced via mutation, using arcs extracted from parent individuals. The selection and combination of arcs is dictated by a vector of strategy parameters. A multi-parent recombination …
A Population-Based Approach to the Resource-Constrained Project Scheduling Problem
2004
We present a population-based approach to the RCPSP. The procedure has two phases. The first phase handles the initial construction of a population of schedules and these are then evolved until high quality solutions are obtained. The evolution of the population is driven by the alternative application of an efficient improving procedure for locally improving the use of resources, and a mechanism for combining schedules that blends scatter search and path relinking characteristics. The objective of the second phase is to explore in depth those vicinities near the high quality schedules. Computational experiments on the standard j120 set, generated using ProGen, show that our algorithm produ…
Material de pràctiques de Matemàtiques II (2013/2014)
2014
Exercicis resolts i proposats i apunts de modelització de problemes de programació matemàtica per a l'assignatura Matemàtiques II dins dels estudis de grau en Economia, en administració i direcció d'empreses i en finances i comptabilitat Solved and proposed exercices and notes on modelling problems of mathematical programming of the subject "Matemàtiques II", in the studies of degree in Economics, degree in business administration and degree in finance and accounting Aquest material ha rebut un dels incentius de la convocatòria 2012 per a la qualitat en l’elaboració de materials docents del Servei de Política Lingüística de la Universitat de València, servei que també ha revisat lingüística…
Development of a New Clusterization Method for the GEM-TPC Detector
2022
The Facility for Antiproton and Ion Research FAIR, in Darmstadt Germany, will be one of the largest accelerator laboratories worldwide. The Superconducting FRagment Separator (Super-FRS)* is one of its main components. The Super-FRS can produce, separate and deliver high-energy radioactive beams with intensities up to 1e11 ions/s, covering projectiles from protons up to uranium and it can be used as an independent experimental device. The Gas Electron Multiplier-based Time Projection Chambers (GEM-TPC) in twin configuration is a newly developed beam tracking detector capable of providing spatial resolution of less than 1 mm with a tracking efficiency close to 100% at 1 MHz counting rate. Th…
Food Security Is None Of Your Business? Food Supply Chain Management In Support Of A Sustainable Food System
2017
Food security is the principal outcome of any given food system and it can be defined in terms of a sustainable food system where the core goal is to feed everyone sustainably, equitably and healthily. A sustainable food system addresses needs for availability, affordability and accessibility, is diverse, ecologically-sound and resilient, and builds the capabilities and skills necessary for future generations. This paper identifies the essential elements of food supply chain management in support of a sustainable food system, which ultimately enhances food security. The existing food supply chain and food system literature is synthesized in order to study the correspondence between public i…
Which firms benefit from investments in green energy technologies? : The effect of energy costs
2019
Abstract Firms will invest in green energy technologies only if these investments have an economic pay-off. Based on unique firm-level data from Austria, Germany, and Switzerland, we find that the marginal effect of investments in green energy technologies on productivity is positive only for the 19% of firms with the highest energy costs. These results have major implications for companies and policy makers regarding the design of green energy policies and incentives.
Myotomy of cricopharungeal muscle in the therapy of dyskinesia of upper esophageal sphincter: personal experience
2012
Dyskinesia of the esophagus includes the entire esophagus from the upper esophageal sphincter to the lower esophageal sphinc - ter together with a wide spectrum of physi - opathological and clinical variations. Related to functional diseases such as Dyskinesia of UES (Upper Esophageal Sphincter), myo- tomy is an excellent procedure for patients with cervical dysphagia. In our experience, the surgical treatment is the only procedure to treat UES dyskinesia. For a successful in - tervention is mandatory: a pharyngeal pump efficiency, hypertension of UES and conservation of esophageal peristalsis in the absence of GERD (Gatroesophageal Reflux Disease). From January 2006 to December 2011, the A…