Spatio-Temporal Event Model for Cyber-Physical Systems

The emerging Cyber-Physical Systems (CPSs) are envisioned to integrate computation, communication and control with the physical world. Therefore, CPS requires close interactions between the cyber and physical worlds both in time and space. These interactions are usually governed by events, which occur in the physical world and should autonomously be reflected in the cyber-world, and actions, which are taken by the CPS as a result of detection of events and certain decision mechanisms. Both event detection and action decision operations should be performed accurately and timely to guarantee temporal and spatial correctness. This calls for a flexible architecture and task representation framework to analyze CP operations. In this paper, we explore the temporal and spatial properties of events, define a novel CPS architecture, and develop a layered spatiotemporal event model for CPS. The event is represented as a function of attribute-based, temporal, and spatial event conditions. Moreover, logical operators are used to combine different types of event conditions to capture composite events. To the best of our knowledge, this is the first event model that captures the heterogeneous characteristics of CPS for formal temporal and spatial analysis.

Structure property relations in complex copolymer systems

A thorough investigation was made of the structure-property relation of well-defined statistical, gradient and block copolymers of various compositions. Among the copolymers studied were those which were synthesized using isobornyl acrylate (IBA) and n-butyl acrylate (nBA) monomer units. The copolymers exhibited several unique properties that make them suitable materials for a range of applications. The thermomechanical properties of these new materials were compared to acrylate homopolymers. By the proper choice of the IBA/nBA monomer ratio, it was possible to tune the glass transition temperature of the statistical P(IBA-co-nBA) copolymers. The measured Tg’s of the copolymers with different IBA/nBA monomer ratios followed a trend that fitted well with the Fox equation prediction. While statistical copolymers showed a single glass transition (Tg between -50 and 90 ºC depending on composition), DSC block copolymers showed two Tg’s and the gradient copolymer showed a single, but very broad, glass transition. PMBL-PBA-PMBL triblock copolymers of different composition ratios were also studied and revealed a microphase separated morphology of mostly cylindrical PMBL domains hexagonally arranged in the PBA matrix. DMA studies confirmed the phase separated morphology of the copolymers. Tensile studies showed the linear PMBL-PBA-PMBL triblock copolymers having a relatively low elongation at break that was increased by replacing the PMBL hard blocks with the less brittle random PMBL-r-PMMA blocks. The 10- and 20-arm PBA-PMBL copolymers which were studied revealed even more unique properties. SAXS results showed a mixture of cylindrical PMBL domains hexagonally arranged in the PBA matrix, as well as lamellar. Despite PMBL’s brittleness, the triblock and multi-arm PBA-PMBL copolymers could become suitable materials for high temperature applications due to PMBL’s high glass transition temperature and high thermal stability. The structure-property relation of multi-arm star PBA-PMMA block copolymers was also investigated. Small-angle X-ray scattering revealed a phase separated morphology of cylindrical PMMA domains hexagonally arranged in the PBA matrix. DMA studies found that these materials possess typical elastomeric behavior in a broad range of service temperatures up to at least 250°C. The ultimate tensile strength and the elastic modulus of the 10- and 20-arm star PBA-PMMA block copolymers are significantly higher than those of their 3-arm or linear ABA type counterparts with similar composition, indicating a strong effect of the number of arms on the tensile properties. Siloxane-based copolymers were also studied and one of the main objectives here was to examine the possibility to synthesize trifluoropropyl-containing siloxane copolymers of gradient distribution of trifluoropropyl groups along the chain. DMA results of the PDMS-PMTFPS siloxane copolymers synthesized via simultaneous copolymerization showed that due to the large difference in reactivity rates of 2,4,6-tris(3,3,3-trifluoropropyl)-2,4,6-trimethylcyclotrisiloxane (F) and hexamethylcyclotrisiloxane (D), a copolymer of almost block structure containing only a narrow intermediate fragment with gradient distribution of the component units was obtained. A more dispersed distribution of the trifluoropropyl groups was obtained by the semi-batch copolymerization process, as the DMA results revealed more ‘‘pure gradient type’’ features for the siloxane copolymers which were synthesized by adding F at a controlled rate to the polymerization of the less reactive D. As with trifluoropropyl-containing siloxane copolymers, vinyl-containing polysiloxanes may be converted to a variety of useful polysiloxane materials by chemical modification. But much like the trifluoropropyl-containing siloxane copolymers, as a result of so much difference in the reactivities between the component units 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane (V) and hexamethylcyclotrisiloxane (D), thermal and mechanical properties of the PDMS-PMVS copolymers obtained by simultaneous copolymerization was similar to those of block copolymers. Only the copolymers obtained by semi-batch method showed properties typical for gradient copolymers.

Stability threshold approach for complex dynamical systems

Acknowledgments This paper was developed within the scope of the IRTG 1740/TRP 2011/50151-0, funded by the DFG/FAPESP, and supported by the Government of the Russian Federation (Agreement No. 14.Z50.31.0033 with the Institute of Applied Physics RAS). The first author thanks Dr Roman Ovsyannikov for valuable discussions regarding estimation of the mistake probability.

Topological structures of complex belief systems

The concepts of substantive beliefs and derived beliefs are defined, a set of substantive beliefs S like open set and the neighborhood of an element substantive belief. A semantic operation of conjunction is defined with a structure of an Abelian group. Mathematical structures exist such as poset beliefs and join-semilattttice beliefs. A metric space of beliefs and the distance of belief depending on the believer are defined. The concepts of closed and opened ball are defined. S′ is defined as subgroup of the metric space of beliefs Σ and S′ is a totally limited set. The term s is defined (substantive belief) in terms of closing of S′. It is deduced that Σ is paracompact due to Stone's Theorem. The pseudometric space of beliefs is defined to show how the metric of the nonbelieving subject has a topological space like a nonmaterial abstract ideal space formed in the mind of the believing subject, fulfilling the conditions of Kuratowski axioms of closure. To establish patterns of materialization of beliefs we are going to consider that these have defined mathematical structures. This will allow us to understand better cultural processes of text, architecture, norms, and education that are forms or the materialization of an ideology. This materialization is the conversion by means of certain mathematical correspondences, of an abstract set whose elements are beliefs or ideas, in an impure set whose elements are material or energetic. Text is a materialization of ideology.

Topological structures of complex belief systems (II): Textual materialization

Mythical and religious belief systems in a social context can be regarded as a conglomeration of sacrosanct rites, which revolve around substantive values that involve an element of faith. Moreover, we can conclude that ideologies, myths and beliefs can all be analyzed in terms of systems within a cultural context. The significance of being able to define ideologies, myths and beliefs as systems is that they can figure in cultural explanations. This, in turn, means that such systems can figure in logic-mathematical analyses.

The prediction and representation of phase equilibria and physicochemical properties in complex slag systems

The development of new experimental techniques for the determination of phase equilibria in complex slag systems, chemical thermodynamic, and viscosity models is reported. The new experimental data, and new thermodynamic and viscosity models, have been combined in a custom-designed computer software package to produce limiting operability diagrams for slag systems. These diagrams are used to describe phase equilibria and physicochemical properties in complex slag systems. The approach is illustrated with calculations on the system FeO-Fe2O3-CaO-SiO-Al2O3 at metallic iron saturation, slags produced in coal slagging gasifiers, and in the reprocessing of nonferrous smelting slags. This article was presented at the Mills Symposium Molten Metals, Slags and Glasses-Characterisation of Properties and Phenomena held in London in August 2000.

Examining the strategy development process through the lens of complex adaptive systems theory

The development of strategy remains a debate for academics and a concern for practitioners. Published research has focused on producing models for strategy development and on studying how strategy is developed in organisations. The Operational Research literature has highlighted the importance of considering complexity within strategic decision making; but little has been done to link strategy development with complexity theories, despite organisations and organisational environments becoming increasingly more complex. We review the dominant streams of strategy development and complexity theories. Our theoretical investigation results in the first conceptual framework which links an established Strategic Operational Research model, the Strategy Development Process model, with complexity via Complex Adaptive Systems theory. We present preliminary findings from the use of this conceptual framework applied to a longitudinal, in-depth case study, to demonstrate the advantages of using this integrated conceptual model. Our research shows that the conceptual model proposed provides rich data and allows for a more holistic examination of the strategy development process. © 2012 Operational Research Society Ltd. All rights reserved.

Strategic development process and complex adaptive systems

The two areas of theory upon which this research was based were „strategy development process?(SDP) and „complex adaptive systems? (CAS), as part of complexity theory, focused on human social organisations. The literature reviewed showed that there is a paucity of empirical work and theory in the overlap of the two areas, providing an opportunity for contributions to knowledge in each area of theory, and for practitioners. An inductive approach was adopted for this research, in an effort to discover new insights to the focus area of study. It was undertaken from within an interpretivist paradigm, and based on a novel conceptual framework. The organisationally intimate nature of the research topic, and the researcher?s circumstances required a research design that was both in-depth and long term. The result was a single, exploratory, case study, which included use of data from 44 in-depth, semi-structured interviews, from 36 people, involving all the top management team members and significant other staff members; observations, rumour and grapevine (ORG) data; and archive data, over a 5½ year period (2005 – 2010). Findings confirm the validity of the conceptual framework, and that complex adaptive systems theory has potential to extend strategy development process theory. It has shown how and why the strategy process developed in the case study organisation by providing deeper insights to the behaviour of the people, their backgrounds, and interactions. Broad predictions of the „latent strategy development? process and some elements of the strategy content are also possible. Based on this research, it is possible to extend the utility of the SDP model by including peoples? behavioural characteristics within the organisation, via complex adaptive systems theory. Further research is recommended to test limits of the application of the conceptual framework and improve its efficacy with more organisations across a variety of sectors.