A Dynamic Model Updating Method with Thermal Effects Based on Improved Support Vector Regression

The dynamic modeling of structures in a thermal environment has become a new research topic in structural dynamics. The amount of calculation caused by the complexity of the structure and the size of the FEM, which increase the difficulty in modeling the structural dynamic thermal effects are considered. In this study, model updating in thermal temperature environment is proposed based on the hierarchical method and improved SVR, and an iterative procedure is presented. First, the dynamic problem of structure under a thermal environment is classified into a thermal model and a structural dynamic model, and they are both constructed with the FE method. As a result, the model updating process is conducted for both the thermal model and structural dynamic model. Different from the variables in other model updating methods, the updating variables, which are composed of the mechanical characteristics and thermal parameters, in the proposed method are dominated by the temperature distribution of the structure. A surrogate model based on improved SVR is adopted in the hierarchical model updating approach to make the updating process more efficient. Finally, the improved SVR method is validated on a typical nonlinear function, and the proposed method is validated by updating the model of an elastic thin plate and a wing structure in a thermal environment.

Response Suppression of Multiple Hinged Floating Structures by Using Rubber Cushion

A brand-new rubber cushion is proposed in this paper, which is installed between hinged floating modules in order to reduce the relative motion of the pitch; meanwhile, the cushion can be used as a fender for anti-impact in the docking process. Using the linear wave potential method, the structural dynamic model is formulated where the equivalent stiffness matrix for the rubber cushion is obtained by an integrating method employing linear assumption in addition to considering the heterogeneity of rubber. A numerical analysis is presented for a two-module semisubmersible floating structure. The hydrodynamic responses and connector loads of the floating structures with a rubber cushion are analyzed by using the frequency domain approach in both regular and irregular waves. The topological design and stiffness parameter selection of the rubber cushion is studied. This work may provide a new idea for suppressing the pitch motion of multiple hinged floating structures.

Ruminative Thinking in Chronic Depression: Concept and Validity of Measures

Despite large amount of empirical evidence in support of rumination as a risk factor of depression onset and chronification, theoretical foundations of ruminative thinking are still being discussed. This includes the issue of so-called constructive, or reflec¬tive, ruminations. Objective: This study gives a theoretical review of different views on rumination, empirically tests the idea of constructive and non-constructive rumi¬native thinking, and tests the validity of the Ruminative Response Scale (RRS, Rus sian version) [38]. Study design: We conducted a factor analysis of adapted RRS, as well as an intercorrelational analysis of this scale, Symptom Checklist-90-Revised (SCL-90-r), and the COPE Inventory; hypotheses were tested in a general population group (n=476) and two clinical groups (patients with depressive disorders, n=53, and patients with different diagnoses with recent suicide attempts, n=41). Results: Our theoretical review examines ruminative thinking as a dysfunctional coping strategy (E. Watkins) from the perspective of the structural-dynamic model of thinking in the course of creative problem-solving (V. Zaretsky, A. Kholmogorova). Rumination is conceptualized as getting stuck «in a loop» at certain levels of organization of cognitive processes, which substitutes motivation focus on actual problem solving. The resulting four-factor structure of RRS has good psychometric properties and strong correla¬tions with different psychopathological symptoms and dysfunctional coping strategies (namely, psychological and behavioral avoidance and venting negative emotions); these correlations are found in all resulting factors but one, which implies that it may have a special status. Conclusion: The Russian version of RRS shows good preliminary psychometric characteristics and is viable for practical purposes. The idea of construc¬tive rumination discussed in literature has not been confirmed empirically. ¬

Structural model updating study in consideration of complex pre-stress distribution

In the present work, to improve the accuracy of the numerical model, the structural model updating problem is investigated in consideration of the influence of pre-stress. In order to eliminate the influence of complex pre-stress on the calculation scale and calculation precision for the continuous structures, the structural dynamic model updating is implemented by using the structural optimization strategy. The optimization function is established, in which the residual value of natural frequency parameter between the finite element model with/without complex pre-stress distribution is defined as objective function under certain constraints. Finally, the thin cylindrical shell structure with welding residual stress distribution, for example, the structural model updating is carried out, and the numerical results verify the feasibility and effectiveness of the proposed method.

The role of collective action for the emergence and consolidation of democracy

The role of citizens' collective action for the emergence and consolidation of democracy is generally analysed within bottom-up theories. However, top-down theories show that elites might impede or promote both democracy and collective action through a set of strategies which are often unobserved and vary over time. Democratic persistence and change require then to be assessed in a dynamic framework which considers both citizens and elites' strategies. For such reason, on a large sample of countries in the period 1971–2014, we jointly estimate the probability of collective action and democracy using a Structural Dynamic Model. This allows us to account for the dynamic nature of the two political phenomena under investigation by controlling for their persistence, for initial conditions and time-varying unobserved heterogeneity. We find that collective action matters for the emergence of democracy but not for its consolidation which seems to be related to more structural economic factors.

System of Value Orientations of Personality and Social Communities: Structural and Dynamic Model and its Application in Psychological Research and Psychological Practice

The present article is an extended version of the report delivered at the meeting of the Presidium of the Russian Academy of Education. The paper introduces an authentic structural and dynamic model of the system of value orientations of the individual and social communities. The model was tested in a series of psychological studies over the past 20 years. The research objective was to verify the authentic structural-dynamic model of value orientations in psychological research and psychological practice. The author used a wide range of psychodiagnostic techniques, focus group research, questionnaire survey, and authentic methodology for the study of the value structure of mass consciousness, etc. The experiments resulted in a set of data that characterize the features of the selected value types, i.e. adapting, socializing, and individualizing. These value types are characterized by a focus on different in their origin and level of development of the value system. They differ in such significant features as the level of meaningfulness of life, internality, and self-actualization. They also have a distinct specificity of the time perspective and life strategy of the individual, as well as the regulation of social behavior. The revealed psychological characteristics of value types open the possibility of forecasting social behavior, as well as the development of technologies for psychological and pedagogical support of the formation of a Pro-social hierarchy of values. The proposed structural-dynamic model is applicable to the characteristics of individual systems of value orientations and the value structure of mass consciousness of different communities. It can explain the patterns of social behavior of community members. The model can be used in psychological science and practice.

A Structural Approach to Assessing Retention Policies in Public Schools

One out of five entering public school teachers leave the field within the first 4 years. Despite that the presence of a newborn child is the single most important determinant of exits of female teachers, retention policy recommendations rely on models that take children as predetermined. This article formulates and estimates a structural dynamic model that explicitly addresses the interdependence between fertility and labor force participation choices. The model with unobserved heterogeneity in preferences for children fits the data and produces reasonable forecasts of labor force attachment to the teaching sector. Structural estimates of the model are used to predict the effects that wage increases and reductions in the cost of childcare would have on female teachers’ employment and fertility choices. The estimates unpack important features of the interdependence of fertility and labor supply and contradict previous studies that did not consider the endogeneity between these two choices.