Diffractive parton distributions from the saturation model

We review diffractive deep inelastic scattering (DIS) in the light of the collinear factorization theorem. This theorem allows to define diffractive parton distributions in the leading twist approach. Due to its selective final states, diffractive DIS offers interesting insight into the form of the diffractive parton distributions which we explore with the help of the saturation model. We find Regge-like factorization with the correct energy dependence measured at HERA. A remarkable feature of diffractive DIS is the dominance of the twist-4 contribution for small diffractive masses. We quantify this effect and make a comparison with the data.Comment: 18 pages, 6 figures, latex, Q_0^2 corrected in comparison to the journal versio

The teaching-learning process through the american culture with students of eighth year of basic education at “Ramón Paéz” educative unit in Latacunga during the academic cycle april 2014- august 2015

This present investigate work was focused on improving the Teaching-Learning Process in the students from eighth year of basic education at “Ramón Paéz” Educative Unit in Latacunga city. The main objective of this investigation was to design workshops design with interesting activities based on American Culture in order to improve the students` English level. The main problem was that students were not learning a language through American Culture and it makes that they were not interested in learning English. In Fact, Students have lack of attention because they do not have the opportunity to acquire a foreign language through interesting activities which allow them have a better interest and knowledge in the English Learning. That is the reason why this investigation has as a purpose to design a workshop based on American Culture….El presente trabajo investigativo estuvo enfocado en mejorar el proceso de enseñanza-aprendizaje en los estudiantes de los Octavos años de Educación básica en el "Ramón Páez" Unidad de Educación en la ciudad de Latacunga. El principal objetivo de esta investigación fue diseñar talleres con actividades interesantes en base a la cultura estadounidense con el fin de mejorar el nivel de Inglés del estudiante. El problema principal era que los alumnos no estaban aprendiendo un idioma a través de la cultura americana e hizo que ellos no estaban interesados en el aprendizaje de Inglés. De hecho, la falta de atención de los estudiantes es porque no tienen la oportunidad de adquirir un lenguaje extranjero a través de interesantes actividades que les permita tener un mejor interés y conocimiento en el aprendizaje del Inglés. Esa es la razón por la que esta investigación tiene como objetivo el diseño de un taller basado en la cultura Americana…

Penalty-based heuristic direct method for constrained global optimization

This paper is concerned with an extension of the heuristic DIRECT method, presented in[8], to solve nonlinear constrained global optimization (CGO) problems. Using a penalty strategy based on a penalty auxiliary function, the CGO problem is transformed into a bound constrained problem. We have analyzed the performance of the proposed algorithm using fixed values of the penalty parameter, and we may conclude that the algorithm competes favourably with other DIRECT-type algorithms in the literature.The authors wish to thank two anonymous referees for their comments and suggestions to improve the paper. This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020, UIDB/00013/2020 and UIDP/00013/2020 of CMAT-UM

The Performance Assessment of Energy Companies

Abstract In the last two decades, in Europe and in Italy, the energy sector undergone a process of liberalization and opening up to competition that involved markets, institutions, companies and consumers. Liberalization has increased the environmental complexity of energy companies, shifting the priority of the management towards the formulation of strategies to gain market share and, at the same time, keep the old customers. The implemented strategies have been different depending on some company characteristics. In Italy, the geographical position has always influenced the company performances. Our paper aims to assess the economic and financial performances of companies, following the beginning of the liberalization process, focusing in particular on how geographical position have influenced the results

Traffic Management of Video on Demand: An Analysis of Investments for Improving the End User's Quality of Experience:

The current escalation in user demand for web contents, particularly Video on Demand (VoD), is causing a continu‐ ing increase in both the types of web traffic and the volumes of data transmitted. The greater demand arises from the new means of communication employed by individuals and companies, as well as the development of readily usable applications distributed by 'app stores'. In this paper, we suggest that the stakeholders of a VoD frame‐ work, the Content Providers (CPs) and the Internet Service Providers (telcos/ISPs), should guarantee a solid Quality of Experience (QoE) to the end user through two potential investments: either in ultra-broadband (UBB) or in the technologies for the acceleration of web content, known as the Content Delivery Network (CDN) and Transparent Internet Caching (TIC). The aim of the paper is to analyse these investments in terms of providers' profits. The base hypothesis is that the investments are subsidized by the CPs, which, in recent years, have indeed been directing a large part of their revenues towards investments in network infrastructure

The Link between the Compliance with Environmental Legislation on Separate Collection and the Municipal Solid Waste Costs

Promoting Agenda 2030 through Circular Economy transition requires improving waste system management and increasing separate collection. In Italy, municipal solid waste management is entrusted to the municipalities, most of which have not yet reached the minimum threshold of 65% for the separate collection imposed by the Environmental Code in 2012. This research aims to investigate the effect of compliance with environmental legislation by Italian municipalities on the total cost of municipal solid waste management, filling a shortage of literature studies on this issue. It also investigates the other significant factors affecting municipal solid waste costs, analysing a large dataset of 1914 municipalities. The study uses regression analysis on aggregate and regional samples and population-based subsamples to verify the existence of economies of scale or density. The results show that environmental compliance determines cost reduction in the northern regions, thanks to more efficient separate collection management and recycling activities in the downstream phases of the process. Instead, environmental compliance produces a cost increase in central regions due to the lack of waste recycling and composting infrastructure. Finally, in the conclusions, policy implications are drawn for the Italian case

A two-objective optimization of ship itineraries for a cruise company

This paper deals with the problem of cruise itinerary planning which plays a central role in worldwide cruise ship tourism. In particular, the Day-by-day Cruise Itinerary Optimization (DCIO) problem is considered. Assuming that a cruise has been planned in terms of homeports and journey duration, the DCIO problem consists in determining the daily schedule of each itinerary so that some Key Performance Indicators are optimized. The schedule of an itinerary, i.e. the sequence of visited ports, the arrival and departure time at each port, greatly affect cruise operative costs and attractiveness. We propose a Mixed Integer Linear Programming (MILP) formulation of the problem with the objective of minimizing the itinerary cost due to fuel and port costs, while maximizing an itinerary attractiveness index. This latter is strongly related to the ports visited as well as to the overall schedule of the itinerary. Therefore the problem turns out to be a bi-objective optimization problem. We provide its solution in terms of Pareto optimal solution points. Each single objective MILP problem which arises is solved by using an exact algorithm,i mplemented in a commercial solver. We consider the day-by-day itineraries of a major luxury cruise company in many geographical areas all over the world. Here we report, as illustrative examples, the results obtained on some of these real instances

Geometric approach to Fletcher's ideal penalty function

Original article can be found at: www.springerlink.com Copyright Springer. [Originally produced as UH Technical Report 280, 1993]In this note, we derive a geometric formulation of an ideal penalty function for equality constrained problems. This differentiable penalty function requires no parameter estimation or adjustment, has numerical conditioning similar to that of the target function from which it is constructed, and also has the desirable property that the strict second-order constrained minima of the target function are precisely those strict second-order unconstrained minima of the penalty function which satisfy the constraints. Such a penalty function can be used to establish termination properties for algorithms which avoid ill-conditioned steps. Numerical values for the penalty function and its derivatives can be calculated efficiently using automatic differentiation techniques.Peer reviewe

Understanding how the strategic similarities between energy companies influence the post-mergers and acquisitions performances

The energy sector has experienced rapid evolution in recent years, following the liberalization of the electricity and natural gas markets, driven by the European Union. These developments have led to a certain level of dynamism in Italy, particularly as concerns mergers and acquisitions (M&As) within the sector. This article examines the influence of strategic similarities between the target and bidder companies on their post-M&A performances. The model used involves a hierarchical regression relating the indexes of similarity between the merging companies, regarding their economic-financial management. The results reveal the influence of the strategic similarities and differences on the post-M&A performances of the companies, showing how the positive or negative effect depends on certain characteristics, such as their structure of share capital, business segments and size. The study evidences the strategic variables that should be considered in choosing the optimal target companies