Location of hubs in a competitive environment

We offer a formulation that locates hubs on a network in a competitiveenvironment; that is, customer capture is sought, which happenswhenever the location of a new hub results in a reduction of thecurrent cost (time, distance) needed by the traffic that goes from thespecified origin to the specified destination.The formulation presented here reduces the number of variables andconstraints as compared to existing covering models. This model issuited for both air passenger and cargo transportation.In this model, each origin-destination flow can go through either oneor two hubs, and each demand point can be assigned to more than a hub,depending on the different destinations of its traffic. Links(``spokes'' have no capacity limit. Computational experience is provided.

Calculation of the variance in surveys of the economic climate

Public opinion surveys have become progressively incorporated into systems of official statistics. Surveys of the economic climate are usually qualitative because they collect opinions of businesspeople and/or experts about the long-term indicators described by a number of variables. In such cases the responses are expressed in ordinal numbers, that is, the respondents verbally report, for example, whether during a given trimester the sales or the new orders have increased, decreased or remained the same as in the previous trimester. These data allow to calculate the percent of respondents in the total population (results are extrapolated), who select every one of the three options. Data are often presented in the form of an index calculated as the difference between the percent of those who claim that a given variable has improved in value and of those who claim that it has deteriorated. As in any survey conducted on a sample the question of the measurement of the sample error of the results has to be addressed, since the error influences both the reliability of the results and the calculation of the sample size adequate for a desired confidence interval. The results presented here are based on data from the Survey of the Business Climate (Encuesta de Clima Empresarial) developed through the collaboration of the Statistical Institute of Catalonia (Institut d’Estadística de Catalunya) with the Chambers of Commerce (Cámaras de Comercio) of Sabadell and Terrassa.

Anàlisi dels fluxos d'aigua, energia i mobilitat a cinc nuclis turístics de Menorca

Menorca és una illa del Mediterrani occidental i una important destinació turística. El turisme estival és un pilar de l’economia de l’illa i té implicacions en tots els aspectes d’aquesta. Una bona part dels turistes es concentren en nuclis turístics costaners dedicats a una única activitat (l’allotjament de turistes). En aquest projecte s’estudien els consums i els potencials de captació d’aigua i energia de cinc nuclis turístics menorquins i alguns dels seus establiments turístics i se n’avalua el potencial d’autosuficiència. També es fa un estudi de mobilitat dels turistes, a partir del qual es quantifica el cost energètic de la mobilitat i les emissions de CO2 que se’n deriven. Les eines utilitzades han estat enquestes i Sistemes d’Informació Geogràfica. Els resultats mostren que el consum hídric per persona és molt variable (de 98 a 466 litres diaris). El consum elèctric per persona és més homogeni que el d’aigua (entre 5 i 10 kWh·persona-1·dia-1 a nivell de nucli turístic) i presenta valors superiors en allotjaments del tipus hotel que del tipus apartaments. Els trajectes d’anada i tornada a l’illa amb avió o vaixell representen més del 80% del cost energètic total de les vacances a Menorca (aprox. 1 MWh per estada) i de les emissions de CO2 associades. Els turistes espanyols recorren un 180% més de distància en desplaçaments a l’interior de l’illa que els d’altres nacionalitats. L’aprofitament d’aigües pluvials podria cobrir menys del 25% de les necessitats hídriques de la majoria d’allotjaments turístics i entre el 28 i el 36% de les necessitats hídriques totals dels nuclis turístics, mantenint-se els nivells actuals de consum. La captació d’energia solar fotovoltaica in situ podria arribar a suplir entre el 50 i el 90% del consum d’energia elèctrica en els nuclis turístics i fins al 100% del mateix en alguns allotjaments turístics.

Quantitative analysis of image factors in a cultural heritage tourist destination

The tourism consumer’s purchase decision process is, to a great extent, conditioned by the image the tourist has of the different destinations that make up his or her choice set. In a highly competitive international tourist market, those responsible for destinations’ promotion and development policies seek differentiation strategies so that they may position the destinations in the most suitable market segments for their product in order to improve their attractiveness to visitors and increase or consolidate the economic benefits that tourism activity generates in their territory. To this end, the main objective we set ourselves in this paper is the empirical analysis of the factors that determine the image formation of Tarragona city as a cultural heritage destination. Without a doubt, UNESCO’s declaration of Tarragona’s artistic and monumental legacies as World Heritage site in the year 2000 meant important international recognition of the quality of the cultural and patrimonial elements offered by the city to the visitors who choose it as a tourist destination. It also represents a strategic opportunity to boost the city’s promotion of tourism and its consolidation as a unique destination given its cultural and patrimonial characteristics. Our work is based on the use of structured and unstructured techniques to identify the factors that determine Tarragona’s tourist destination image and that have a decisive influence on visitors’ process of choice of destination. In addition to being able to ascertain Tarragona’s global tourist image, we consider that the heterogeneity of its visitors requires a more detailed study that enables us to segment visitor typology. We consider that the information provided by these results may prove of great interest to those responsible for local tourism policy, both when designing products and when promoting the destination.

Localitzador gràfic d'adreces IP

Tracta la realització de l'estudi sobre el sistema d'adreçament IP a Internet, a fi d'obtenir una aplicació que ens mostri gràficament sobre un mapa mundial el recorregut des de l'origen fins la destinació. També subministra informació parcial obtinguda al procés de consultes.

Bottled natural mineral water in catalonia: origin and geographical evolution of its consumption and production

During the second half of the nineteenth century a major mineral water bottling industry appeared in Catalonia which vigorously lasted until the first third of the 20th century. The fact that the industry appeared in Catalonia and in other parts of Europe and the United States almost at the same time and had not existed before can be explained by a series of factors which coincided in time. This situation encouraged producers to pack, transport and sell bottled water from their respective sources. Among these factors there is the rise of hygienism, very influential in Catalonia, the declining water quality due to industrialization, the increase in population density, the improvement in transport, the emergence of thermal tourism or the invention of better containers used to store water. This project aims to explain thoroughly all the mentioned factors, and to give some light to why, when and how the Catalan bottled water industry appeared.

Classification of sags according to their origin based on the waveform similarity

A statistical method for classification of sags their origin downstream or upstream from the recording point is proposed in this work. The goal is to obtain a statistical model using the sag waveforms useful to characterise one type of sags and to discriminate them from the other type. This model is built on the basis of multi-way principal component analysis an later used to project the available registers in a new space with lower dimension. Thus, a case base of diagnosed sags is built in the projection space. Finally classification is done by comparing new sags against the existing in the case base. Similarity is defined in the projection space using a combination of distances to recover the nearest neighbours to the new sag. Finally the method assigns the origin of the new sag according to the origin of their neighbours

Discovering similarities in the time use patterns of the Spanish Autonomous Communities by Fuzzy techniques

In 2000 the European Statistical Office published the guidelines for developing theHarmonized European Time Use Surveys system. Under such a unified framework,the first Time Use Survey of national scope was conducted in Spain during 2002–03. The aim of these surveys is to understand human behavior and the lifestyle ofpeople. Time allocation data are of compositional nature in origin, that is, they aresubject to non-negativity and constant-sum constraints. Thus, standard multivariatetechniques cannot be directly applied to analyze them. The goal of this work is toidentify homogeneous Spanish Autonomous Communities with regard to the typicalactivity pattern of their respective populations. To this end, fuzzy clustering approachis followed. Rather than the hard partitioning of classical clustering, where objects areallocated to only a single group, fuzzy method identify overlapping groups of objectsby allowing them to belong to more than one group. Concretely, the probabilistic fuzzyc-means algorithm is conveniently adapted to deal with the Spanish Time Use Surveymicrodata. As a result, a map distinguishing Autonomous Communities with similaractivity pattern is drawn.Key words: Time use data, Fuzzy clustering; FCM; simplex space; Aitchison distance

On the origin and scope of the second language speech production disadvatage

Los hablantes bilingües tienen un acceso al léxico más lento y menos robusto que los monolingües, incluso cuando hablan en su lengua materna y dominante. Este fenómeno, comúnmente llamado “la desventaja bilingüe” también se observa en hablantes de una segunda lengua en comparación con hablantes de una primera lengua. Una causa que posiblemente contribuya a estas desventajas es el uso de control inhibitorio durante la producción del lenguaje: la inhibición de palabras coactivadas de la lengua actualmente no en uso puede prevenir intrusiones de dicha lengua, pero al mismo tiempo ralentizar la producción del lenguaje. El primer objetivo de los estudios descritos en este informe era testear esta hipótesis mediante diferentes predicciones generadas por teorías de control inhibitorio del lenguaje. Un segundo objetivo era investigar la extensión de la desventaja bilingüe dentro y fuera de la producción de palabras aisladas, así como avanzar en el conocimiento de las variables que la modulan. En lo atingente al primer objetivo, la evidencia obtenida es incompatible con un control inhibitorio global, desafiando la idea de mecanismos específicos en el hablante bilingüe utilizados para la selección léxica. Esto implica que una explicación común para el control de lenguaje y la desventaja bilingüe en el acceso al léxico es poco plausible. En cuanto al segundo objetivo, los resultados muestran que (a) la desventaja bilingüe no tiene un impacto al acceso a la memoria; (b) la desventaja bilingüe extiende a la producción del habla conectada; y (c) similitudes entre lenguas a diferentes niveles de representación así como la frecuencia de uso son factores que modulan la desventaja bilingüe.   

Assimilació, integració laboral, domini de l'idioma i segregació residencial

La literatura econòmica sobre immigració i mercat de treball ha analitzat dos grans temes. Un és l’efecte que genera la immigració sobre les condicions laborals (ocupació i salaris) dels nadius. L’altre és l’assimilació dels immigrants en el país d’acollida. Aquest projecte s'emmarca en aquesta segona línia de recerca. L’assimilació s’entén com un procés complex en el que un immigrant s’integra completament en el seu país d’acollida en diferents aspectes interrelacionats: l’estatus socioeconòmic, el progrés salarial, el domini de l’idioma o la segregació residencial, entre d'altres. El nostre projecte es centra en l’anàlisi de l’assimilació dels immigrants que han arribat recentment al nostre mercat de treball. Des d'aquesta perspectiva, s'ha analitzat si com a conseqüència de la transferibilitat limitada del capital humà entre països, es produeix o no una degradació ocupacional inicial que porti associada una quantiosa diferència salarial amb els nadius de similars característiques. De fet, com menys transferible sigui el capital humà d'origen, major serà la degradació ocupacional i la consegüent bretxa salarial inicial. També s'ha analitzat de manera més directa quin paper juga la portabilitat del capital humà a l'hora d'explicar el progrés econòmic dels immigrants. L’evidència obtinguda permet concloure que, a mesura que s'amplia el temps de residència al país de destinació, el capital humà es va adaptant als requeriments del mercat laboral del país hoste, especialment a través de l'experiència en el lloc de treball, però també per aprenentatge del nou idioma o fins i tot realització d'estudis. El capital humà així acumulat permet millorar posicions en l'escala ocupacional i augmentar en paral•lel els ingressos, assimilant-los amb el temps als dels nadius d'iguals característiques. Per últim, l’anàlisi del paper de les xarxes socials dels immigrants mostra un efecte positiu sobre la probabilitat de trobar feina però un pitjor emparellament en el mercat de treball.

L’elecció del centre en famílies d’origen immigrat a la ciutat de Barcelona

El projecte ha assolit la majoria d’objectius, ajustats a la reducció d'una quarta part de l'import concedit: 1) caracteritzar la transformació del paisatge agro-forestal i urbà a dos municipis de la vall del Congost, La Garriga i Figaró-Montmany, reconstruint amb SIG els mapes d'ús del sòl de 1854, 1949, 1956 i 2005, obtenint per intersecció de cobertes les matrius dels canvis d'ús; i 2) avaluar amb l’índex de connectivitat ecològica l'impacte ambiental d'aquells canvis des del punt de vista de la biodiversitat i la resiliència del paisatges, amb un especial èmfasi en la reforestació induïda per l'abandonament rural i la pèrdua de paisatges en mosaic, en un àmbit més gran pel període 1956-1993-2005. Aquests resultats han permès preparar varis articles per publicar en co-autoría a revistes com Landscape History, Environment and History o Landscape and Urban Planning. Ja és a punt de poder-se lliurar el primer amb el títol de "Looking backwards into a Mediterranean edge environment: Landscape changes and ecological connectivity in El Congost Valley (province of Barcelona, Catalonia) 1850-2005", incloent dos objectius esmentats a la memòria: identificar les principals forces motores d'aquells canvis en el paisatge relacionant els usos del sòl amb les formes d'ordenació del territori, caracteritzar-ne les forces rectores econòmico-socials i el paper jugat per la protecció del Parc Natural del Montseny i els Cingles de Bertí. Els resultats també permetran abordar en el futur altres aspectes, com per exemple estimar el potencial energètic de la biomassa local tot cercant que el seu aprofitament generi sinèrgies territorials positives per a l'ecologia del paisatge amb la recuperació d’una ramaderia extensiva i una agricultura ecològica que facin possible la restauració dels paisatges en mosaic. L'estudi ha pogut incorporar un aspecte inicialment no previst, el cens d'orquídies mediterrànies a Figaró-Montmany elaborat pel naturalista Paul Wilcox.

Origin and genetic differentiation of Three Mexican Native Groups (Purépechas, Triquis and Mayas): contribution of CODIS-STRs to the history of human populations of Mesoamerica

BACKGROUND: CODIS-STRs in Native Mexican groups have rarely been analysed for human identification and anthropological purposes. AIM:To analyse the genetic relationships and population structure among three Native Mexican groups from Mesoamerica.SUBJECTS AND METHODS: 531 unrelated Native individuals from Mexico were PCR-typed for 15 and 9 autosomal STRs (Identifiler™ and Profiler™ kits, respectively), including five population samples: Purépechas (Mountain, Valley and Lake), Triquis and Yucatec Mayas. Previously published STR data were included in the analyses. RESULTS:Allele frequencies and statistical parameters of forensic importance were estimated by population. The majority of Native groups were not differentiated pairwise, excepting Triquis and Purépechas, which was attributable to their relative geographic and cultural isolation. Although Mayas, Triquis and Purépechas-Mountain presented the highest number of private alleles, suggesting recurrent gene flow, the elevated differentiation of Triquis indicates a different origin of this gene flow. Interestingly, Huastecos and Mayas were not differentiated, which is in agreement with the archaeological hypothesis that Huastecos represent an ancestral Maya group. Interpopulation variability was greater in Natives than in Mestizos, both significant.CONCLUSION: Although results suggest that European admixture has increased the similarity between Native Mexican groups, the differentiation and inconsistent clustering by language or geography stresses the importance of serial founder effect and/or genetic drift in showing their present genetic relationships.

Genetic origin, admixture, and asymmetry in maternal and paternal human lineages in Cuba

Background: Before the arrival of Europeans to Cuba, the island was inhabited by two Native American groups, the Tainos and the Ciboneys. Most of the present archaeological, linguistic and ancient DNA evidence indicates a South American origin for these populations. In colonial times, Cuban Native American people were replaced by European settlers and slaves from Africa. It is still unknown however, to what extent their genetic pool intermingled with and was 'diluted' by the arrival of newcomers. In order to investigate the demographic processes that gave rise to the current Cuban population, we analyzed the hypervariable region I (HVS-I) and five single nucleotide polymorphisms (SNPs) in the mitochondrial DNA (mtDNA) coding region in 245 individuals, and 40 Y-chromosome SNPs in 132 male individuals. Results: The Native American contribution to present-day Cubans accounted for 33% of the maternal lineages, whereas Africa and Eurasia contributed 45% and 22% of the lineages, respectively. This Native American substrate in Cuba cannot be traced back to a single origin within the American continent, as previously suggested by ancient DNA analyses. Strikingly, no Native American lineages were found for the Y-chromosome, for which the Eurasian and African contributions were around 80% and 20%, respectively. Conclusion: While the ancestral Native American substrate is still appreciable in the maternal lineages, the extensive process of population admixture in Cuba has left no trace of the paternal Native American lineages, mirroring the strong sexual bias in the admixture processes taking place during colonial times.

Methods and representativeness of European surveys in children and adolescents: the KIDSCREEN study

Background: The objective of the present study was to compare three different sampling and questionnaire administration methods used in the international KIDSCREEN study in terms of participation, response rates, and external validity. Methods: Children and adolescents aged 8–18 years were surveyed in 13 European countries using either telephone sampling and mail administration, random sampling of school listings followed by classroom or mail administration, or multistage random sampling of communities and households with self-administration of the survey materials at home. Cooperation, completion, and response rates were compared across countries and survey methods. Data on non-respondents was collected in 8 countries. The population fraction (PF, respondents in each sex-age, or educational level category, divided by the population in the same category from Eurostat census data) and population fraction ratio (PFR, ratio of PF) and their corresponding 95% confidence intervals were used to analyze differences by country between the KIDSCREEN samples and a reference Eurostat population. Results: Response rates by country ranged from 18.9% to 91.2%. Response rates were highest in the school-based surveys (69.0%–91.2%). Sample proportions by age and gender were similar to the reference Eurostat population in most countries, although boys and adolescents were slightly underrepresented (PFR <1). Parents in lower educational categories were less likely to participate (PFR <1 in 5 countries). Parents in higher educational categories were overrepresented when the school and household sampling strategies were used (PFR = 1.78–2.97). Conclusion: School-based sampling achieved the highest overall response rates but also produced slightly more biased samples than the other methods. The results suggest that the samples were sufficiently representative to provide reference population values for the KIDSCREEN instrument.

A reassessment of family reunification in Europe. The case of Senegalese couples

Contemporary policy makers in most European destination countriesexpress a great concern about reunification of migrants’ families. Newrestrictions multiply in almost all countries, on the grounds thatmigrants would take advantage of a too lax system and that it wouldfoster an influx of non-desirable migrants. So far, quantitative evidenceis scarce on migrants’ practices in matter of family reunification.Taking advantage of a unique longitudinal dataset that includesSenegalese individuals surveyed both at origin (in Senegal) and inEurope (France, Italy and Spain), we perform event-history analyses toshow three things. First, couple separation is very often a long lastingsituation. Second, when separated because of international migration,wives and husbands do not only reunify in Europe but quite commonlyin Senegal. And third, those who reunify in Europe are those who arethe most adapted or adaptable to the European culture and economy.