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91.
Verena D. Schmittmann Angélique O.J. CramerLourens J. Waldorp Sacha EpskampRogier A. Kievit Denny Borsboom 《New Ideas in Psychology》2013
In psychological measurement, two interpretations of measurement systems have been developed: the reflective interpretation, in which the measured attribute is conceptualized as the common cause of the observables, and the formative interpretation, in which the measured attribute is seen as the common effect of the observables. We advocate a third interpretation, in which attributes are conceptualized as systems of causally coupled (observable) variables. In such a view, a construct like ’depression’ is not seen as a latent variable that underlies symptoms like ’lack of sleep’ or ’fatigue’, and neither as a composite constructed out of these symptoms, but as a system of causal relations between the symptoms themselves (e.g., lack of sleep → fatigue, etc.). We discuss methodological strategies to investigate such systems as well as theoretical consequences that bear on the question in which sense such a construct could be interpreted as real. 相似文献
92.
This study examines the dynamic regulation process responding to an external stimulus. The damped oscillator model has been used to describe this process. However, the model does not allow a nonzero steady state, even though the oscillations may continue and do not necessarily damp toward zero. This study introduces the driven damped oscillator model which has an additional parameter to identify different patterns of the steady state. Three methods, generalized local linear approximation, continuous time structural equation modeling, and analytic solutions of differential equations are provided to estimate model parameters. A simulation study indicates that parameters in the driven damped oscillator model are well recovered. The model is then illustrated using a data set on the daily reports of sales after a sale promotion. Potential applications and possible expansions of this model are also discussed. 相似文献
93.
David Weissman 《Metaphilosophy》2013,44(5):589-603
Traditional moral theory usually has either of two emphases: virtuous moral character or principles for distributing duties or goods. “Zone morality” introduces a third: families and businesses are systems created by the causal reciprocities of their members. These relations embody the duties and permissions of a system's moral code. Core systems satisfy basic interests and needs; we move easily among them, hardly noticing that moral demands vary from system to system. Moral conflicts arise because of discord within or among systems but also because morality has three competing sites: personal attitudes and practices (benevolence or hostility), the moral codes of systems, and regulative principles that enhance social cohesion. A strong church or central government reduces conflict by imposing its rules. A democracy responds by encouraging persons and systems to participate in forums where claims are made; it promises fairness by requiring that all satisfy its legal procedures. 相似文献
94.
95.
Human participants and recurrent (“connectionist”) neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular (“strong”) classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the Elsewhere Condition (Kiparsky, 1973). Previous connectionist accounts of related phenomena have often been vague about the nature of the networks’ encoding systems. We analyzed our network using dynamical systems theory, revealing topological and geometric properties that can be directly compared with the mechanisms of non‐connectionist, rule‐based accounts. The results reveal that the networks “contain” structures related to mechanisms posited by rule‐based models, partly vindicating the insights of these models. On the other hand, they support the one mechanism (OM), as opposed to the more than one mechanism (MOM), view of symbolic abstraction by showing how the appearance of MOM behavior can arise emergently from one underlying set of principles. The key new contribution of this study is to show that dynamical systems theory can allow us to explicitly characterize the relationship between the two perspectives in implemented models. 相似文献
96.
High-pressure X-ray diffraction studies on gadolinium sesquioxide (Gd2O3) have been carried out up to a pressure of ~25 GPa in a diamond-anvil cell at room temperature. Gadolinium oxide, which has a cubic or bixbyite structure under ambient conditions, undergoes an irreversible structural phase at around 12 GPa. The high-pressure phase has been identified as a hexagonal La2O3-type structure. The bulk modulus and its pressure derivative of this phase have been calculated. 相似文献
97.
In a study of radiation effects in SnO we have found that electron-beam damage is observable from changes in a high-resolution electron microscopy image or electron diffraction pattern. The early stage of the damage is not accompanied by a change in composition or a loss of crystallinity. The dose required for this damage (about 600 C cm?2) is approximately independent of electron energy (between 100 and 400 keV) and specimen temperature (between 100 and 300 K). The damage is believed to start with displacement of oxygen atoms from their lattice position through a radiolytic mechanism with an efficiency of approximately 10?4. 相似文献
98.
It is shown that initially sharp interface in AB diffusion couple, above the ordering temperature, can shift with anomalous kinetics, i.e. deviations from the parabolic growth kinetics are possible. The initial slopes of the shift versus time functions can be even unity for large diffusion asymmetry (the ratio of diffusion coefficients of the parent materials in orders of magnitude) and gradually decrease to 0.5 at larger distances (longer times). This is in accordance with earlier results obtained in phase separating systems. It is shown that from the results of simulations the crossover thickness, X*, between the linear and parabolic regimes can also be calculated, and the applicability of the linear–parabolic law is confirmed. Furthermore, it is illustrated that the crossover thickness depends exponentially on the diffusion asymmetry parameter, with the exponent close to the value obtained from analytical estimations. 相似文献
99.
Denis Edwards 《Theology & Science》2013,11(2):245-247
AbstractThe article examines the notion of self-organization and explores the reality of biological processes from an epistemological point of view. First, I briefly analyze what is currently regarded as one of the most important discoveries not only in physics, but also in biology—namely, complex systems and deterministic chaos; secondly, I offer some reflections on the new frontiers of contemporary biology— namely, functional genomics and systems biology. The central part of the article focuses on the epistemological transition from genetic determinism to the new conception of “meaning” as emergence. 相似文献
100.
Joshua B. Johnson 《Journal of aggression, maltreatment & trauma》2013,22(1):45-66
To prevent youth violence, the GREAT Families program was implemented with a selective sample of 1,196 families of sixth-grade children from low-income schools in 4 cities making the transition to adolescence. To assess intervention effects, we used pre- and posttest data to estimate a structural model to test the hypothesis that random assignment to the intervention would predict changes in parenting practices, which in turn would predict changes in exposure to violence (i.e., a mediational model). We found that participation in GREAT was significantly related to changes in parenting practices and these changes significantly predicted changes in violence exposure. Furthermore, adolescents who reported greater increases in exposure to violence also tended to experience greater decreases in parental monitoring, discipline, and involvement. Implications for future research and prevention efforts are discussed. 相似文献