Enlargement and transition. Mobile scientists in the growing European Union

This article aims to analyse the impact of transitional periods on researchers’ mobility decisions in the enlarging Europe. A compilation of policy and law analyses, together with social research, is the adopted method for this study. Countries under research are Poland and Bulgaria, as sending countries, and Germany and the UK, representing the EU member states that opted for and against transitional periods, respectively. The political environment in Europe, in which researcher’s mobility is taking place, is presented along with the characteristics of scientific mobility as part of the international migratory flows. The question asked is, how the perception of enlargement influences mobility decisions of scientists. The results of qualitative research proved only to a certain extent the hypothesis, that countries with no transitional periods introduced were more attractive for scientists from new member states than the countries with such periods introduced. The analysis showed that although various administrative and legal barriers do represent impediments to scientific mobility, yet they were not usually decisive factors for mobility

Combating the illegal employment of foreigners in the enlargement EU: the case of Poland

"The specific objective of this project is to provide policy-makers and practitioners with a good understanding of the impact of irregular employment of foreigners on the labour markets of the selected EU countries as well its potential for infringement on migrants' rights and for their exploitation; the identification of best measures taken to bombat this phenomenon both by sending and receiving countries; and to contribute to administrative cooperation and information exchange among the participating countries on preventing irregular and promoting legal channals for employment. The current paper focuses on the case of Poland." (author's abstract

Einwanderungspolitik in einem Auswandererland

Nach den Massenumsiedlungen der Nachkriegszeit entwickelte sich Polen unter kommunistischer Herrschaft zu einem Land, in dem die Auswanderung von oben her beschränkt wurde und eine Einwanderung praktisch nicht stattfand. Aus politischen und wirtschaftlichen Gründen stand Polen vor 1989 abseits der Wege, die Asylsuchende einschlugen. Der Umbruch im Jahre 1989 und die anschließende politische und wirtschaftliche Transformation in Polen sowie in den übrigen Ländern Ostmittel- und Osteuropas führten zu einer wesentlichen Veränderung des Bildes der Wanderungsbewegungen in Polen. Zwar bleibt die Emigration um ein vielfaches höher als die Immigration, doch kommen nun Ausländer aus verschiedenen Ländern und mit unterschiedlichem Rechtsstatus nach Polen, legal und illegal. Polen ist für sie entweder Durchgangsland auf dem Weg nach Westen oder, immer öfter, Ziel ihrer Migration. Die Autorin stellt die unterschiedlichen Beweggründe für die Einwanderung nach Polen und die Lebenssituation der Immigranten dar und skizziert die aktuelle Ausländerpolitik

Distributed Evolutionary Design: Island-Model-based Optimization of Steel Skeleton Structures in Tall Buildings

This paper presents results of a study on distributed, or parallel, evolutionary computation in the topological design of steel structural systems in tall buildings. It describes results of extensive experimental research on various parallel evolutionary architectures applied to a complex structural design problem. The experiments were conducted using Inventor 2003, a networkbased evolutionary design support tool developed at George Mason University. First, a general introduction to evolutionary computation is provided with an emphasis on recent developments in parallel evolutionary architectures. Next, a discussion of conceptual design of steel structural systems in tall buildings is presented. Further, Inventor 2003 is briefly introduced as well as its design representation and evolutionary computation characteristics. Next, the results obtained from systematic design experiments conducted with Inventor 2003 are discussed. The objective of these experiments was to qualitatively and quantitatively investigate evolution of steel structural systems in tall buildings during a distributed evolutionary design process as well as to compare efficiency and effectiveness of various parallel evolutionary architectures with the traditional evolutionary design approaches. Two connectivity topologies (ring topology and fully-connected topology) have been investigated for four populations of structural designs evolving in parallel and using various migration strategies. Also, results of the initial sensitivity studies are reported in which two ways of initializing distributed evolutionary design processes were investigated, using either arbitrarily selected designs as initial parents or randomly generated ones. Finally, initial research conclusions are presented

The CareFirst Patient-Centered Medical Home Program: Cost and Utilization Effects in Its First Three Years

Background Enhanced primary care models have diffused slowly and shown uneven results. Because their structural features are costly and challenging for small practices to implement, they offer modest rewards for improved performance, and improvement takes time. Objective To test whether a patient-centered medical home (PCMH) model that significantly rewarded cost savings and accommodated small primary care practices was associated with lower spending, fewer hospital admissions, and fewer emergency room visits. Design We compared medical care expenditures and utilization among adults who participated in the PCMH program to adults who did not participate. We computed difference-in-difference estimates using two-part multivariate generalized linear models for expenditures and negative binomial models for utilization. Control variables included patient demographics, county, chronic condition indicators, and illness severity. Participants A total of 1,433,297 adults aged 18–64 years, residing in Maryland, Virginia, and the District of Columbia, and insured by CareFirst for at least 3 consecutive months between 2010 and 2013. Intervention CareFirst implemented enhanced fee-for-service payments to the practices, offered a large retrospective bonus if annual cost and quality targets were exceeded, and provided information and care coordination support. Measures Outcomes were quarterly claims expenditures per member for all covered services, inpatient care, emergency care, and prescription drugs, and quarterly inpatient admissions and emergency room visits. Results By the third intervention year, annual adjusted total claims payments were $109 per participating member (95$192, −$27), or 2.8 % lower than before the program and compared to those who did not participate. Forty-two percent of the overall decline in spending was explained by lower inpatient care, emergency care, and prescription drug spending. Much of the reduction in inpatient and emergency spending was explained by lower utilization of services. Conclusions A PCMH model that does not require practices to make infrastructure investments and that rewards cost savings can reduce spending and utilization

Design of prestressed concrete precast road bridges with hybrid simulated annealing

This paper describes one approach to the analysis and design of prestressed concrete precast road bridges, with double U-shaped cross-section and isostatic spans. The procedure used to solve the combinatorial problem is a variant of simulated annealing with a neighborhood move based on the mutation operator from the genetic algorithms (SAMO). This algorithm is applied to the economic cost of these structures at different stages of manufacturing, transportation and construction. The problem involved 59 discrete design variables for the geometry of the beam and the slab, materials in the two elements, as well as active and passive reinforcement. The parametric study showed a good orrelation for the cost, geometric and reinforcement characteristics with the span length, which can be useful for the day-to-day design of PC precast bridges. A cost sensitivity analysis first indicates that a maximum 20% rise in steel costs leads to an 11.82% increase in the cost, while a 20% rise in concrete costs increases the cost up to 4.20%, namely 2.8 times less. The analysis also indicated that the characteristics of the cost-optimized bridges are somewhat influenced by different economic scenarios for steel and concrete costs. Finally, there is a growth in the volume of concrete when the steel cost rises; surprisingly, the variation in the volume of concrete is almost insensitive to its rising price.This work was supported by the Universitat Politecnica de Valencia (Research Project PAID-06-09) and the Spanish Ministry of Science and Innovation (Research Project BIA2011-23602). The authors are grateful to the anonymous reviewers for their constructive comments and useful suggestions. The authors are also grateful to Dr. Debra Westall for her thorough revision of the manuscript.Martí Albiñana, JV.; González Vidosa, F.; Yepes Piqueras, V.; Alcalá González, J. (2013). Design of prestressed concrete precast road bridges with hybrid simulated annealing. Engineering Structures. 48:342-352. https://doi.org/10.1016/j.engstruct.2012.09.014S3423524

Heuristic optimization of RC bridge piers with rectangular hollow sections

This paper deals with the economic optimization of reinforced concrete (RC) bridge piers with hollow rectangular sections and describes the efficiency of three heuristic algorithms: two new variants of the ant colony optimization (ACO) algorithm, the genetic algorithm (GA) and the threshold acceptance (TA) algorithm. The GA and TA are used for comparison with the new ACO algorithms. The total number of variables is 95. All variables are discrete in this analysis. The calibration of the new ACO algorithm recommended a 250-member ant population and 100 stages. The best solution costs 69,467 euros, which means savings of about 33% as compared to experience-based design. Finally, results indicate that the new ACO algorithms are potentially useful for optimizing the costs of real RC structures.This study was funded by the Spanish Ministry of Education (Research Project BIA2006-01444). The authors are grateful for the thorough revision of the manuscript by Dr. Debra Westall.Martínez Martín, FJ.; González Vidosa, F.; Hospitaler Pérez, A.; Yepes Piqueras, V. (2010). Heuristic optimization of RC bridge piers with rectangular hollow sections. Computers and Structures. 88:375-386. https://doi.org/10.1016/j.compstruc.2009.11.009S3753868

Búsqueda exhaustiva por entornos aplicada al diseño económico de bóvedas de hormigón armado

[EN] This paper presents two gradient algorithms applied to the economic optimization of reinforced concrete vaults, typically used in the construction of underpasses. The algorithms are gradient multi start neighbourhood exhaustive search procedures. The vault is defined by 45 design variables and the objective function is an economic one. Both methods have been applied to a vault of 12.40 m of diameter and 3.00 m of lateral walls. Design variables have been coded in base 2 for algorithms GB1 and in Gray coding for GB2. The neighbourhood is defined by the set of solutions that differ in one bit. The Gray coding solves the lack of proximity between two solutions typical of the ordinary binary coding. The positive effect of the Gray coding is proven in the present paper, where the average cost of 3,000 runs of GB2 improves by 3.81% a similar run by algorithm GB1. In addition, GB2 attains the best cost solution. The paper includes a stop criterion for the algorithm based on the stability of the statistics of the multi start results. The algorithms are simple and can be applied to other structural problems. The structure of best cost has a high slenderness and a span to depth ratio of 40. The study reports savings of 6% when compared to a design by an experienced practitioner office. © 2010 CIMNE (UPC). Published by Elsevier España, S.L. All rights reserved.[ES] El artículo presenta dos algoritmos multiarranque de búsqueda exhaustiva por entornos de máximo gradiente aplicados a la optimización económica de una bóveda de hormigón armado empleada en la construcción de pasos inferiores. La bóveda se define mediante 45 variables discretas, siendo la función objetivo el coste. Los métodos se han aplicado a una bóveda de 12,40 m de diámetro interior y 3,00 m de altura de hastiales, con un relleno de tierras de 1,00 m sobre clave. Las variables se han codificado en base 2 para el algoritmo GB1 y en codificación Gray para el algoritmo GB2. El entorno queda definido por el conjunto de soluciones que difieren de la solución actual en un solo dígito. La codificación Gray soluciona la falta de adyacencia entre soluciones próximas que conlleva la codificación binaria ordinaria. Su efecto positivo se comprueba en el artículo, donde el coste medio de 3.000 ejecuciones de GB2 es un 3,81% menor a 3.000 ejecuciones de GB1; además, ha permitido alcanzar la solución de coste mínimo. El artículo plantea un criterio de parada de un algoritmo multiarranque basado en la estabilidad de los estadísticos de la muestra de óptimos locales obtenidos hasta el momento. El algoritmo presentado es sencillo y generalizable a cualquier estructura. La estructura de coste mínimo presenta una esbeltez importante en la bóveda, con una relación canto/luz inferior a 1/40. Se han encontrado ahorros cercanos al 6% respecto a una bóveda real disenada siguiendo los procedimientos habituales de cálculo de una oficina de proyectos experimentada. © 2010 CIMNE (UPC). Publicado por Elsevier España, S.L. Todos los derechos reservados.Carbonell Lombardero, A.; Yepes Piqueras, V.; González Vidosa, F. (2011). Búsqueda exhaustiva por entornos aplicada al diseño económico de bóvedas de hormigón armado. Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería. 27(3):227-235. doi:10.1016/j.rimni.2011.07.003S22723527

Population and labour force projections for 27 European countries, 2002-052: impact of international migration on population ageing: Projections de population et de population active pour 27 pays européens 2002-052: impact de la migration internationale sur le vieillissement de la population

Population and labour force projections are made for 27 selected European countries for 2002-052, focussing on the impact of international migration on population and labour force dynamics. Starting from single scenarios for fertility, mortality and economic activity, three sets of assumptions are explored regarding migration flows, taking into account probable policy developments in Europe following the enlargement of the EU. In addition to age structures, various support ratio indicators are analysed. The results indicate that plausible immigration cannot offset the negative effects of population and labour force ageing