Measure of Global Specialization and Spatial Clustering for the Identification of "Specialized" Agglomeration

The intensity of regional specialization in specific activities, and conversely, the level of industrial concentration in specific locations, has been used as a complementary evidence for the existence and significance of externalities. Additionally, economists have mainly focused the debate on disentangling the sources of specialization and concentration processes according to three vectors: natural advantages, internal, and external scale economies. The arbitrariness of partitions plays a key role in capturing these effects, while the selection of the partition would have to reflect the actual characteristics of the economy. Thus, the identification of spatial boundaries to measure specialization becomes critical, since most likely the model will be adapted to different scales of distance, and be influenced by different types of externalities or economies of agglomeration, which are based on the mechanisms of interaction with particular requirements of spatial proximity. This work is based on the analysis of the spatial aspect of economic specialization supported by the manufacturing industry case. The main objective is to propose, for discrete and continuous space: i) a measure of global specialization; ii) a local disaggregation of the global measure; and iii) a spatial clustering method for the identification of specialized agglomerations.

Peer and group relationships in preschoolers: the role of social and linguistic skills

Being able to positively interact and build relationships with playmates in preschool years is crucial to achieve positive adjustment. An update review and two studies on such topics were provided. Study 1 is observational; it investigates the type of social experience in groups (N = 443) of children (N = 120) at preschool age in child-led vs. teacher-led contexts. The results revealed that in child-led contexts children were more likely to be alone, in dyads, and in small peer groups; groups were mostly characterized by same-gender playmates who engaged in joint interactions, with few social interactions with teachers. In teacher-led contexts, on the other hand, children were more likely to be involved in small, medium and large groups; groups were mostly characterized by other-gender playmates, involved in parallel interactions, with teachers playing a more active role. The purpose of Study 2 was to describe the development of socio-emotional competence, temperamental traits and linguistic skill. It examined the role of children’s reciprocated nominations (=RNs) with peers, assessed via sociometric interview, in relation to socio-emotional competence, temperamental traits and linguistic skill. Finally, the similarity-homophily tendency was investigated. Socio-emotional competence and temperamental traits were assessed via teacher ratings, linguistic skill via test administration. Eighty-four preschool children (M age = 62.53) were recruited within 4 preschool settings. Those children were quite representative of preschool population. The results revealed that children with higher RNs showed higher social competence (tendency), social orientation, positive emotionality, motor activity and linguistic skill. They exhibited lower anxiety-withdrawal. The results also showed that children prefer playmates with similar features: social competence, anger-aggression (tendency), social orientation, positive emotionality, inhibition to innovation, attention, motor activity (tendency) and linguistic skill. Implications for future research were suggested.

Methods for Clearance Influence Analysis in Planar and Spatial Mechanisms

This doctoral dissertation presents a new method to asses the influence of clearancein the kinematic pairs on the configuration of planar and spatial mechanisms. The subject has been widely investigated in both past and present scientific literature, and is approached in different ways: a static/kinetostatic way, which looks for the clearance take-up due to the external loads on the mechanism; a probabilistic way, which expresses clearance-due displacements using probability density functions; a dynamic way, which evaluates dynamic effects like the actual forces in the pairs caused by impacts, or the consequent vibrations. This dissertation presents a new method to approach the problem of clearance. The problem is studied from a purely kinematic perspective. With reference to a given mechanism configuration, the pose (position and orientation) error of the mechanism link of interest is expressed as a vector function of the degrees of freedom introduced in each pair by clearance: the presence of clearance in a kinematic pair, in facts, causes the actual pair to have more degrees of freedom than the theoretical clearance-free one. The clearance-due degrees of freedom are bounded by the pair geometry. A proper modelling of clearance-affected pairs allows expressing such bounding through analytical functions. It is then possible to study the problem as a maximization problem, where a continuous function (the pose error of the link of interest) subject to some constraints (the analytical functions bounding clearance- due degrees of freedom) has to be maximize. Revolute, prismatic, cylindrical, and spherical clearance-affected pairs have been analytically modelled; with reference to mechanisms involving such pairs, the solution to the maximization problem has been obtained in a closed form.

Effect of mixing, particle interaction, and spatial dimension on the glass transition

In this thesis, the influence of composition changes on the glass transition behavior of binary liquids in two and three spatial dimensions (2D/3D) is studied in the framework of mode-coupling theory (MCT).The well-established MCT equations are generalized to isotropic and homogeneous multicomponent liquids in arbitrary spatial dimensions. Furthermore, a new method is introduced which allows a fast and precise determination of special properties of glass transition lines. The new equations are then applied to the following model systems: binary mixtures of hard disks/spheres in 2D/3D, binary mixtures of dipolar point particles in 2D, and binary mixtures of dipolar hard disks in 2D. Some general features of the glass transition lines are also discussed. The direct comparison of the binary hard disk/sphere models in 2D/3D shows similar qualitative behavior. Particularly, for binary mixtures of hard disks in 2D the same four so-called mixing effects are identified as have been found before by Götze and Voigtmann for binary hard spheres in 3D [Phys. Rev. E 67, 021502 (2003)]. For instance, depending on the size disparity, adding a second component to a one-component liquid may lead to a stabilization of either the liquid or the glassy state. The MCT results for the 2D system are on a qualitative level in agreement with available computer simulation data. Furthermore, the glass transition diagram found for binary hard disks in 2D strongly resembles the corresponding random close packing diagram. Concerning dipolar systems, it is demonstrated that the experimental system of König et al. [Eur. Phys. J. E 18, 287 (2005)] is well described by binary point dipoles in 2D through a comparison between the experimental partial structure factors and those from computer simulations. For such mixtures of point particles it is demonstrated that MCT predicts always a plasticization effect, i.e. a stabilization of the liquid state due to mixing, in contrast to binary hard disks in 2D or binary hard spheres in 3D. It is demonstrated that the predicted plasticization effect is in qualitative agreement with experimental results. Finally, a glass transition diagram for binary mixtures of dipolar hard disks in 2D is calculated. These results demonstrate that at higher packing fractions there is a competition between the mixing effects occurring for binary hard disks in 2D and those for binary point dipoles in 2D.

Design and Characterization of Curved and Spherical Flexure Hinges for Planar and Spatial Compliant Mechanisms

A flexure hinge is a flexible connector that can provide a limited rotational motion between two rigid parts by means of material deformation. These connectors can be used to substitute traditional kinematic pairs (like bearing couplings) in rigid-body mechanisms. When compared to their rigid-body counterpart, flexure hinges are characterized by reduced weight, absence of backlash and friction, part-count reduction, but restricted range of motion. There are several types of flexure hinges in the literature that have been studied and characterized for different applications. In our study, we have introduced new types of flexures with curved structures i.e. circularly curved-beam flexures and spherical flexures. These flexures have been utilized for both planar applications (e.g. articulated robotic fingers) and spatial applications (e.g. spherical compliant mechanisms). We have derived closed-form compliance equations for both circularly curved-beam flexures and spherical flexures. Each element of the spatial compliance matrix is analytically computed as a function of hinge dimensions and employed material. The theoretical model is then validated by comparing analytical data with the results obtained through Finite Element Analysis. A case study is also presented for each class of flexures, concerning the potential applications in the optimal design of planar and spatial compliant mechanisms. Each case study is followed by comparing the performance of these novel flexures with the performance of commonly used geometries in terms of principle compliance factors, parasitic motions and maximum stress demands. Furthermore, we have extended our study to the design and analysis of serial and parallel compliant mechanisms, where the proposed flexures have been employed to achieve spatial motions e.g. compliant spherical joints.

Mortality from road traffic accidents in Switzerland: longitudinal and spatial analyses

Road traffic accidents (RTA) are an important cause of premature death. We examined socio-demographic and geographical determinants of RTA mortality in Switzerland by linking 2000 census data to RTA mortality records 2000-2005 (ICD-10 codes V00-V99). Data from 5.5 million residents aged 18-94 years, 1744 study areas, and 1620 RTA deaths were analyzed, including 978 deaths (60.4%) in motor vehicle occupants, 254 (15.7%) in motorcyclists, 107 (6.6%) in cyclists, and 259 (16.0%) in pedestrians. Weibull survival models and Bayesian methods were used to calculate hazard ratios (HR), and standardized mortality ratios (SMR) across study areas. Adjusted HR comparing women with men ranged from 0.04 (95% CI 0.02-0.07) in motorcyclists to 0.43 (95% CI 0.32-0.56) in pedestrians. There was a u-shaped relationship with age in motor vehicle occupants and motorcyclists. In cyclists and pedestrians, mortality increased after age 55 years. Mortality was higher in individuals with primary education (HR 1.53; 95% CI 1.29-1.81), and higher in single (HR 1.24; 95% CI 1.05-1.46), widowed (HR 1.31; 95% CI 1.05-1.65) and divorced individuals (HR 1.62; 95% CI 1.33-1.97), compared to persons with tertiary education or married persons. The association with education was particularly strong for pedestrians (HR 1.87; 95% CI 1.20-2.91). RTA mortality increased with decreasing population density of study areas for motor vehicle occupants (test for trend p<0.0001) and motorcyclists (p=0.0021) but not for cyclists (p=0.39) or pedestrians (p=0.29). SMR standardized for socio-demographic and geographical variables ranged from 82 to 190. Prevention efforts should aim to reduce inequities across socio-demographic and educational groups, and across geographical areas, with interventions targeted at high-risk groups and areas, and different traffic users, including pedestrians.

Money is not enough: exploring the impact of social and cultural resources on youth health

Findings on socioeconomic health differentials in youth remain fragmented with the role of cumulative and interaction effects of different forms of health resources not well understood.

AN EXAMINATION OF THE STARS-PAC ANXIETY INTERVENTION PROGRAM AND ITS EFFECTS ON DECREASING SOCIAL AND TEST ANXIETY

The current case study examined the effects of the STARS-PAC anxiety reduction program on the social and test anxiety levels of a middle school student. The literature supporting the effectiveness of cognitive behavioral therapy programs which incorporate methods such as those used in the STARS-PAC program were reviewed. The findings of this case study indicated decreased levels of overall anxiety during the intervention phase; however, the student’s test anxiety level displayed little improvement. Implications of the findings and for future research are discussed.

Aggressive Behaviour of Different Social and Demographic Groups in Post-Totalitarian Society

The project looked at aggressiveness in different age and social groups of modern post-totalitarian society, beginning with the hypotheses that the greatest risk groups are teenagers and the unemployed, and that there is a link between aggression and the level of meaningfulness of life. The groups studied comprised about 200 persons from urban areas of eastern Ukraine, including schoolchildren, students, white collar workers, self-employed persons, the unemployed and pensioners. Workers in industry were not included as this group has virtually disappeared in Ukraine at present since most enterprises have ceased to work and most workers have moved into the groups of the unemployed or self-employed. Participants were divided into age groups of 13-14, 16-17, 18-22, 24-45, 46-60 and over 60, with each group including approximately equal number of men and women. Research methods included Buss-Darky techniques, the "hand test" (E. Wagner), the "non-existent animal" technique, a Rozenzweig picture frustration study, purpose-in-life tests and an interview. The Buss-Darky test showed that schoolchildren have the highest level of aggression, followed by students. These groups have high indexes in virtually all types of aggression, including its open form. The self-employed have relatively lower indexes, although they are more likely to manifest it openly, while such open manifestations are less likely among white-collar workers, pensioners and the unemployed. The least aggressive were the unemployed and pensioners, although the latter had a relatively high level of hostility. In terms of age, aggression was shown to decrease with age, which Ms. Ivanova attributes to the still imperfect control mechanisms of teenagers and their less mature personalities. Among the younger groups girls showed a slightly higher level of aggression, although this situation was reversed among older people. The risk groups inclined to manifest open forms of aggressiveness can therefore be seen to be teenagers and students. Other tests used show aggressiveness as a feature of the current state, rather than as an inherent feature and the results obtained were somewhat different. In the interviews, all adults referred to the increased aggressiveness in society and most stated that they themselves had become more aggressive and bad-tempered. The ability of individuals to adapt to their social environment was also investigated and schoolchildren turned out to have the lowest adaptation index and the unemployed the highest. MS. Ivanova attributes that latter, rather surprising, result to the fact that the constant frustrations facing the unemployed force them to actively seek ways and means of adapting in order to survive. The final aspect considered was the possible connection between human aggressiveness and the meaningfulness of life. Here the groups with the most meaningful lives were the self-employed and pensioners. The latter result, again rather surprising, was attributed to the desire of people who have already lived the greater part of their lives to place more weight on what they have already done, in order to prove to themselves that they have not lived in vain. The hypothesis that aggressiveness is conversely related to the meaningfulness of life was only partially confirmed. In the two extreme cases (schoolchildren and pensioners) this was indeed the case, but the remaining groups did not show any such connection. From the data obtained, Ms. Ivanova concluded that life in modern post-totalitarian society does indeed foster a rise in people's aggressiveness, and this was supported by the fact that indexes of aggressiveness proved to be higher than the norm. Her original hypothesis as to the groups in society most at risk from open aggression confirmed in the case of teenagers but not of the unemployed, who had relatively low aggressiveness indexes and the highest degree of adaptation.

The Influence of the Social and Cultural Environment on a Child's Playing in the First Three Years of Life

The research focused on children's behaviour in playing with objects both independently and in interaction with adults. It was based on studies of 40 Slovene children in 4 age groups (6,12,18 and 24 months) and of 23 Croatian children in 2 age groups (18 and 24 months). All the children were sampled proportionally by their gender and the educational level of their parents (middle and higher). Several coding check lists with satisfactory internal consistency were constructed during the study and used to analyse the video-recorded playing sessions with each child. The basic conclusion reached was that even in early childhood playing behaviour differs significantly between the infants from the two Central European countries. The difference lies not so much in the structure or the content of the playing actions, but in the way in which the infants deal playfully with the objects. This difference appears regardless of the type of object the infants are playing with and even regardless of the playing condition. It can best be described as the difference between the first significant discriminant function activity versus passivity. The Slovene infants were found to be on the active pole and the Croatians on the passive one. Social and gender differences were much less significant than cultural ones in determining the structure, the content and the way of playing. Significant age differences appeared in all three aspects, which was consistent with general trends in infants' psychological development. The group define the Slovene interactive playing style as object oriented, while the Croatian one was largely communicated oriented. Within the experimenter-infant dyads, children of both cultures played at a developmentally more advanced level than they did with their mothers, showing that the mothers were not as successful at reaching the ZPD as were the trained experimenters. In addition, the children of mothers who attributed more cognitive benefit to play played on a more advanced level than those whose mothers attributed more emotional benefit to play. The quality of the object the children were playing with was also significantly related to the structure, content and partly the way of dealing with the objects. Highly-structured objects stimulated complex play and low-structured ones stimulated simple play, regardless of playing conditions. The group concluded that both culture and the quality of the available object have an important impact on young children's play. Through the playing interaction, the infants internalise culturally specific patterns of behaviour and culturally specific meanings. These internalisations become apparent very early in their lives, even in non-social situations. On the other hand, the objects themselves have an impact on the level of infants' play. When they do not provide sufficient perceptive and functional support for a representational action, the infants' play will lag behind their actual developmental capacities.