The Non-linear Dynamics of Meaning-Processing in Social Systems

Social order cannot be considered as a stable phenomenon because it contains an order of reproduced expectations. When the expectations operate upon one another, they generate a non-linear dynamics that processes meaning. Specific meaning can be stabilized, for example, in social institutions, but all meaning arises from a horizon of possible meanings. Using Luhmann's (1984) social systems theory and Rosen's (1985) theory of anticipatory systems, I submit equations for modeling the processing of meaning in inter-human communication. First, a self-referential system can use a model of itself for the anticipation. Under the condition of functional differentiation, the social system can be expected to entertain a set of models; each model can also contain a model of the other models. Two anticipatory mechanisms are then possible: one transversal between the models, and a longitudinal one providing the modeled systems with meaning from the perspective of hindsight. A system containing two anticipatory mechanisms can become hyper-incursive. Without making decisions, however, a hyper-incursive system would be overloaded with uncertainty. Under this pressure, informed decisions tend to replace the "natural preferences" of agents and an order of cultural expectations can increasingly be shaped

Efficient prediction of the forced response statistics of mistuned bladed discs

This paper presents two efficient reduced-order modelling techniques for predicting the forced response statistics of bladed disc assemblies. First, the formulation presented in (1) is extended to the forced response problem. Component modes for a blade-disc sector are used as basis vectors, leading to a reduced model of the same size as the number of sectors and allowing for pass-band calculations. For each realization of the random system parameters, a reduced system of equations is solved to compute the displacement vector for each frequency band of interest. Statistics of responses at each frequency point can be therefore estimated by performing Monte Carlo Simulations of cost comparable to single degree-of-freedom mass-spring systems. Second, a stochastic reduced basis approach is applied to the mistuning analysis problem. Here, the system response in the frequency domain is represented using a linear combination of complex stochastic basis vectors which span the preconditioned stochastic Krylov Subspace (2,3). Orthogonal stochastic projection schemes are employed for computing the undetermined coefficients in the stochastic reduced basis representation. These schemes lead to explicit expressions for the response to be obtained, thereby allowing the efficient computation of the response statistics

In vitro evaluation of tetrazoles as a novel class of Antimycobacterium tuberculosis agents

Purpose: We report here the antimycobacterial activity of some already synthesized tetrazole derivatives containing tetrazole against Mycobacterium tuberculosis strain H37Rv. Methods: In vitro evaluation of the antitubercular activity was carried out within the Tuberculosis Antimicrobial Acquisition & Coordinating Facility (TAACF) screening program for the discovery of novel drugs for the treatment of tuberculosis. Under the direction of the US National Institute of Allergy and Infectious Diseases (NIAID), Southern Research Institute that coordinates the overall program. The method of TAACF was followed for evaluation of activity. Results: This new structural class of compounds showed high activity against the bacilli. The activity depends on the substituent’s present in azatidinone core. Compounds having a 4-MeOC6H4 4-N(CH3)2C6H4 group as the substituent on β-lactam ring were active. The highest activity was registered for compounds having 4-MeOC6H4 as substituent. Conclusion: The new compounds showed high potency and promising antitubercular activity and should be regarded as new hits for further development as a novel class of Antimycobacterium tuberculosis agents

Forced response statistics of mistuned bladed disks: a stochastic reduced basis approach

This paper presents a stochastic reduced basis approach for predicting the forced response statistics of mistuned bladed-disk assemblies. In this approach, the system response in the frequency domain is represented using a linear combination of complex stochastic basis vectors with undermined coefficients. The terms of the preconditioned stochastic Krylov subspace are used here as basis vectors. Two variants of the stochastic Bubnov–Galerkin scheme are employed for computing the undetermined terms in the reduced basis representation, which arise from how the condition for orthogonality between two random vectors is interpreted. Explicit expressions for the response quantities can then be derived in terms of the random system parameters, which allow for the possibility of efficiently computing the response statistics in the post-processing stage. Numerical studies are presented for mistuned cyclic assemblies of mono-coupled single-mode components. It is demonstrated that the accuracy of the response statistical moments computed using stochastic reduced basis methods can be orders of magnitude better than classical perturbation methods. <br/

Neutron and gamma radiation effects on MEMS structures

MEMS technology is expected to play a significant role in future space missions provided the effects of radiation on the reliability of MEMS devices is well understood [1]. Radiation induced dielectric charging has been identified as a mechanism which can potentially limit the reliability of electrostatically actuated MEMS devices [2]. The response of piezoresistive and PZT actuated MEMS was also found to change after exposure to different types of radiation [3]. It is however necessary to further investigate the effect of radiation and especially neutrons on the electromechanical properties of various materials that are used in microfabrication [4]. In this work we present results from mechanical and electrical tests on different materials before and after exposure to neutrons radiation

Modelling the risks of extreme weather events for Australasian hospital infrastructure using rich picture diagrams

This is a Submitted Manuscript of an article published by Taylor & Francis in 'Construction Management and Economics' on 05/10/2012, available online: http://dx.doi.org/10.1080/01446193.2012.725941.Anticipated increases in the frequency of extreme weather events in the future are likely to expose hospital infrastructure to new risks which are poorly understood. Traditional approaches to risk identification and analysis produce linear, narrow and static risk profiles which fail to consider complex sub-system interdependencies that may assist or hinder healthcare delivery during an extreme weather event. The ability to create resilient hospitals depends on new risk management methodologies which provide an understanding of these complex relationships. Focus groups with key stakeholders in three hospitals in Australia are used to construct rich picture diagrams (RPDs) of hospital infrastructure interdependencies under different extreme weather event scenarios. They show that the risks posed to hospitals by extreme weather events cannot be considered in isolation from the surrounding infrastructure, emergency management systems, health systems and communities in which they are imbedded. The new insights provided have major governance and policy implications for agencies responsible for ensuring that hospital infrastructure can continue to support the delivery of effective health services during extreme weather events