Project: NIH | Enhancement of Quantitati... (1T36GM078000-01), NIH | Enhancement of Quantitati... (1T36GM078000-01)
In many real-life applications (e.g., in aircraft maintenance), we need to estimate the probability of failure of a complex system (such as an aircraft as a whole or one of its subsystems). Complex systems are usually built with redundancy allowing them to withstand the failure of a small number of components. In this paper, we assume that we know the structure of the system, and, as a result, for each possible set of failed components, we can tell whether this set will lead to a system failure. For each component A, we know the probability P(A) of its failure with some uncertainty: e.g., we know the lower and upper bounds P(A) and P(A) for this probability. Usually, it is assumed that failures of different components are independent events. Our objective is to use all this information to estimate the probability of failure of the entire the complex system. In this paper, we describe several methods for solving this problem, including a new efficient method for such estimation based on Cauchy deviates.
Publisher: Universidad Politecnica de Madrid - University Library
La ocupación efectiva del territorio austral chileno se produjo en la segunda mitad del siglo XIX. Para su ejecución fueron claves las medidas dictadas por el Estado a través del denominado “proyecto de colonización”, que favoreció la llegada de inmigrantes procedentes de Europa durante un periodo de grandes flujos migratorios hacia el continente americano. La ciudad de Valdivia fue el punto de partida de este proyecto. En 1845 desembarcan los pobladores procedentes de los territorios de la Confederación Alemana. En esta ciudad se producen los primeros intercambios culturales entre la población local y la extranjera, en un “laboratorio constructivo” que estableció las bases de la arquitectura de la colonización y determinó la formación de la vivienda tradicional del sur del país. Mediante un estudio histórico y constructivo hemos identificado los invariantes arquitectónicos generados en este periodo de la colonización. Hemos comprobado su permanencia en distintos ejemplos de viviendas tradicionales localizadas, entre las ciudades de Valdivia y Puerto Montt, a lo largo del territorio que fue ocupado entre 1845 y 1875 con esta población alemana.
Publisher: Educational and Instructional Center for Railway Transportation
The device of flexitanks, as well as technical and technological features of the transportation of goods with their use, are considered. The relevance of the topic is due to the fact that at present almost 80 % of international transit in the world takes place in containers, on the domestic markets of the largest countries of the world, goods flows also go mainly in containers. Flexitanks are studied as innovative tools for organizing the chains of delivery of goods and goods in containers, having all the necessary equipment for transporting various kinds of cargo.Analytical and marketing methods are applied, taking into account the principles of the theory of logistics, logic, as well as shared materials.A comparison of this type of packaging with other transportation means is presented. It was revealed that flexitara is more oriented to non-hazardous liquid cargo in terms of its characteristics. The use of flexitanks allows to reduce transportation costs, reduce labor, time and transportation costs, as well as to carry out multimodal transportation using various modes of transport.It is established that flexitanks can act as a full-fledged and multi-functional alternative to tanks, tank containers and other containers for transporting bulk materials that are non-hazardous cargoes. The use of technology for the transportation of goods in flexitanks will contribute to the further innovative development of multi-modal freight transportation and the growth of containerization of goods exchange in general.
Publisher: Springer Science and Business Media LLC
We propose an extension of the classical real-valued external penalty method to the multicriteria optimization setting. As its single objective counterpart, it also requires an external penalty function for the constraint set, as well as an exogenous divergent sequence of nonnegative real numbers, the so-called penalty parameters, but, differently from the scalar procedure, the vector-valued method uses an auxiliary function, which can be chosen among large classes of “monotonic” real-valued mappings. We analyze the properties of the auxiliary functions in those classes and exhibit some examples. The convergence results are similar to those of the scalar-valued method, and depending on the kind of auxiliary function used in the implementation, under standard assumptions, the generated infeasible sequences converge to weak Pareto or Pareto optimal points. We also propose an implementable local version of the external penalization method and study its convergence results.
This paper reports on some of the findings of a recent study on the employment impact of moving to a rural area. A case study approach is used to elucidate the choices/constraints/compromises encountered by women in in-migrant households to rural and semi-rural parts of the East Midlands, Great Britain. Rural labour markets are quantitatively and qualitatively different from urban labour markets and, while some of the surveyed in-migrant women managed to find jobs following their move, they often experienced downward occupational mobility; others withdrew from the labour market. A number of policy recommendations are also made to improve labour market access.
Nowadays, projects represent a significantinvestment for organizations, their intrinsic role asorganizational change mechanisms is being increasinglyrecognized. In this context, project portfolio management effortsare considered as a main efficiency and effectiveness mechanismto align the projects execution with the organization strategy. Thecomponents of a project portfolio management should bemeasured, ranked, and prioritized according to criteria preestablished. The main objective of the PhD research work is todevelop a new method for portfolio management of Informationand Technology projects, by taking into account the implicationsfrom Project Management Institute and Office of GovernmentCommerce project and program management reference models.
In this study, a capacitated lot sizing problem (CLSP) which suffers uncertainty by the equipment degradation is investigated. Condition-based maintenance (CBM) is considered with aperiodic inspection at the beginning of every batch. And a prognosis threshold is taken to decide the maintenance action. A predictive planning model is proposed to make the production and maintenance plan considering the uncertain degradation of the equipment. The objective is to minimize the expected total cost during a finite planning horizon, including production, maintenance and depreciation costs. A two-stage relaxation heuristic algorithm is designed and the results show that the method has a good quality.