51 research outputs found

    The Cultural Evolution of Democracy: Saltational Changes in A Political Regime Landscape

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    Transitions to democracy are most often considered the outcome of historical modernization processes. Socio-economic changes, such as increases in per capita GNP, education levels, urbanization and communication, have traditionally been found to be correlates or ‘requisites’ of democratic reform. However, transition times and the number of reform steps have not been studied comprehensively. Here we show that historically, transitions to democracy have mainly occurred through rapid leaps rather than slow and incremental transition steps, with a median time from autocracy to democracy of 2.4 years, and overnight in the reverse direction. Our results show that autocracy and democracy have acted as peaks in an evolutionary landscape of possible modes of institutional arrangements. Only scarcely have there been slow incremental transitions. We discuss our results in relation to the application of phylogenetic comparative methods in cultural evolution and point out that the evolving unit in this system is the institutional arrangement, not the individual country which is instead better regarded as the ‘host’ for the political system

    Effects of etizolam and ethyl loflazepate on the P300 event-related potential in healthy subjects

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    <p>Abstract</p> <p>Background</p> <p>Benzodiazepines carry the risk of inducing cognitive impairments, which may go unnoticed while profoundly disturbing social activity. Furthermore, these impairments are partly associated with the elimination half-life (EH) of the substance from the body. The object of the present study was to examine the effects of etizolam and ethyl loflazepate, with EHs of 6 h and 122 h, respectively, on information processing in healthy subjects.</p> <p>Methods</p> <p>Healthy people were administered etizolam and ethyl loflazepate acutely and subchronically (14 days). The auditory P300 event-related potential and the neuropsychological batteries described below were employed to assess the effects of drugs on cognition. The P300 event-related potential was recorded before and after drug treatments. The digit symbol test, trail making test, digit span test and verbal paired associates test were administered to examine mental slowing and memory functioning.</p> <p>Results</p> <p>Acute administration of drugs caused prolongation in P300 latency and reduction in P300 amplitude. Etizolam caused a statistically significant prolongation in P300 latency compared to ethyl loflazepate. Furthermore, subchronic administration of etizolam, but not ethyl loflazepate, still caused a weak prolongation in P300 latency. In contrast, neuropsychological tests showed no difference.</p> <p>Conclusions</p> <p>The results indicate that acute administration of ethyl loflazepate induces less effect on P300 latency than etizolam.</p

    A service-oriented reconfigurable process monitoring system - enabling cyber physical systems

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    Communication is an essential requirement for collaborative manufacturing systems. However the diversity of communication media and protocols in machine tools, automation equipment, and associated proprietary software, presents a challenge for enabling capable, extensible and re-configurable process monitoring systems. Additionally, as process control systems evolve from centralised hierarchical structures to decentralised heterarchical communities, enabling media and tools are required to provide interoperability between systems and subsystems. The focus of this research is to introduce a manufacturing decentralised process monitoring architecture that utilises a service-oriented architecture framework for network-wide dynamic data acquisition and distribution. The system design is created using a combination of service-oriented architecture topology and technical modelling. Service-oriented communication structure and capability is given particular focus, resulting in a comparative study of message structures and communication speeds. The resultant system is modular in structure, reconfigurable, network-distributable, interoperable, efficient, and meets real-time requirements

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    Data interoperability for reconfigurable manufacturing process monitoring systems

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    The ability for manufacturing organisation to be responsive to changing market conditions is imperative for sustainable market competitiveness, and enabling self preservation. Responsive behaviour requires the incorporation of not only robust sustainable manufacturing process chains, but the functional capacity to facilitate reconfiguration and adaption. Manufacturing process chains require process monitoring and condition based monitoring systems to achieve high accuracy manufacturing systems, sustainable production capability, and resource efficiency. The focus of this research is aimed at developing a novel data interoperability architecture to enable the creation of reconfigurable process monitoring systems. To achieve reconfigurable process monitoring capability an information communication paradigm known as agent based design is reviewed, and an emerging agent based standard known as MTConnect is also reviewed. Through this research a novel data interoperability system is developed and defined to enable dynamic data acquisition for reconfigurable process monitoring. A case study is carried out to demonstrate the validity of the architecture to achieve multi data stream unification. This case study demonstrates the ability to actively condition monitor a HURCO VM2 three axis CNC machine dynamically, through the measurement of machine energy requirements and vibration, which are examples of process variables associated with condition based machine monitoring

    The effects of process parameters on spindle power consumption in abrasive machining of CoCr alloy

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    The production environment requires seamless integration, efficiency and robustness of process monitoring solutions. This research investigates data acquisition on the machine tool through the monitoring of NC kernel data. This approach provides many advantages, particularly in an industrial setting where it may be impractical to install additional sensors for process monitoring. The process investigated is abrasive machining of Cobalt Chrome alloy. Cobalt Chrome alloys are extensively used in the biomedical industry as both femoral and tibial components of prosthetic joints. Abrasive machining or grinding is widely employed as the main method for material removal for these components. Understanding the influence of key variables in such a process is necessary before optimization can be achieved. Significant information can be obtained by utilizing power consumption during machining as a process metric. Power consumption of a spindle during an abrasive machining process of Cobalt Chrome alloy is monitored under various conditions through a machine-NC-based application. The effects of changes in feed rate, wheel speed, depth of cut and tool condition are investigated here through Taguchi experimental design. Experimental results are presented with significant machining variables identified
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