12 resultados para Astronautics and state

em Aston University Research Archive


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This article analyses the ambiguous and contradictory relationship between the Orthodox Church and the communist regime during the first two years of the Romanian People's Republic. The installation of communism and the process of Stalinisation led to an unprecedented control of the church. The church was actively employed in propaganda and the regime imposed its own people in the hierarchy. On the one hand, Romanian communists followed the Soviet model regarding the place of the church in the communist state while, on the other hand, the church hierarchy adapted to the new political system by creating a theory of 'social apostolate'. Lacking popular support, the communists used the church as an instrument through which they could acquire the political support of the masses. The church thus enjoyed a favoured position in society mainly because the communists employed it in their ideological expansionism and confrontation with the West.

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Nanotechnologies have been called the "Next Industrial Revolution." At the same time, scientists are raising concerns about the potential health and environmental risks related to the nano-sized materials used in nanotechnologies. Analyses suggest that current U.S. federal regulatory structures are not likely to adequately address these risks in a proactive manner. Given these trends, the premise of this paper is that state and local-level agencies will likely deal with many "end-of-pipe" issues as nanomaterials enter environmental media without prior toxicity testing, federal standards, or emissions controls. In this paper we (1) briefly describe potential environmental risks and benefits related to emerging nanotechnologies; (2) outline the capacities of the Toxic Substances Control Act, the Clean Air Act, the Clean Water Act, and the Resources Conservation and Recovery Act to address potential nanotechnology risks, and how risk data gaps challenge these regulations; (3) outline some of the key data gaps that challenge state-level regulatory capacities to address nanotechnologies' potential risks, using Wisconsin as a case study; and (4) discuss advantages and disadvantages of state versus federal approaches to nanotechnology risk regulation. In summary, we suggest some ways government agencies can be better prepared to address nanotechnology risk knowledge gaps and risk management.

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This article analyses the relationship between Orthodoxy and state from the unification of the Principalities of Moldavia and Wallachia in 1859 to the creation of Greater Romania in 1918. Examining the attitudes of political leaders towards the dominant religion, this article argues that during the reigns of Prince Cuza and King Carol I the Church became a state institution closely connected to the development of political regimes. It is suggested that by claiming doctrinal religious connections with Constantinople and independence from foreign intervention in the Church’s affairs, religious and political leaders from 1859 to 1918 amplified the construction of Romanian national mythology which contributed towards the political unity of the state.

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Liquid-liquid extraction has long been known as a unit operation that plays an important role in industry. This process is well known for its complexity and sensitivity to operation conditions. This thesis presents an attempt to explore the dynamics and control of this process using a systematic approach and state of the art control system design techniques. The process was studied first experimentally under carefully selected. operation conditions, which resembles the ranges employed practically under stable and efficient conditions. Data were collected at steady state conditions using adequate sampling techniques for the dispersed and continuous phases as well as during the transients of the column with the aid of a computer-based online data logging system and online concentration analysis. A stagewise single stage backflow model was improved to mimic the dynamic operation of the column. The developed model accounts for the variation in hydrodynamics, mass transfer, and physical properties throughout the length of the column. End effects were treated by addition of stages at the column entrances. Two parameters were incorporated in the model namely; mass transfer weight factor to correct for the assumption of no mass transfer in the. settling zones at each stage and the backmixing coefficients to handle the axial dispersion phenomena encountered in the course of column operation. The parameters were estimated by minimizing the differences between the experimental and the model predicted concentration profiles at steady state conditions using non-linear optimisation technique. The estimated values were then correlated as functions of operating parameters and were incorporated in·the model equations. The model equations comprise a stiff differential~algebraic system. This system was solved using the GEAR ODE solver. The calculated concentration profiles were compared to those experimentally measured. A very good agreement of the two profiles was achieved within a percent relative error of ±2.S%. The developed rigorous dynamic model of the extraction column was used to derive linear time-invariant reduced-order models that relate the input variables (agitator speed, solvent feed flowrate and concentration, feed concentration and flowrate) to the output variables (raffinate concentration and extract concentration) using the asymptotic method of system identification. The reduced-order models were shown to be accurate in capturing the dynamic behaviour of the process with a maximum modelling prediction error of I %. The simplicity and accuracy of the derived reduced-order models allow for control system design and analysis of such complicated processes. The extraction column is a typical multivariable process with agitator speed and solvent feed flowrate considered as manipulative variables; raffinate concentration and extract concentration as controlled variables and the feeds concentration and feed flowrate as disturbance variables. The control system design of the extraction process was tackled as multi-loop decentralised SISO (Single Input Single Output) as well as centralised MIMO (Multi-Input Multi-Output) system using both conventional and model-based control techniques such as IMC (Internal Model Control) and MPC (Model Predictive Control). Control performance of each control scheme was. studied in terms of stability, speed of response, sensitivity to modelling errors (robustness), setpoint tracking capabilities and load rejection. For decentralised control, multiple loops were assigned to pair.each manipulated variable with each controlled variable according to the interaction analysis and other pairing criteria such as relative gain array (RGA), singular value analysis (SVD). Loops namely Rotor speed-Raffinate concentration and Solvent flowrate Extract concentration showed weak interaction. Multivariable MPC has shown more effective performance compared to other conventional techniques since it accounts for loops interaction, time delays, and input-output variables constraints.

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Amongst all the objectives in the study of time series, uncovering the dynamic law of its generation is probably the most important. When the underlying dynamics are not available, time series modelling consists of developing a model which best explains a sequence of observations. In this thesis, we consider hidden space models for analysing and describing time series. We first provide an introduction to the principal concepts of hidden state models and draw an analogy between hidden Markov models and state space models. Central ideas such as hidden state inference or parameter estimation are reviewed in detail. A key part of multivariate time series analysis is identifying the delay between different variables. We present a novel approach for time delay estimating in a non-stationary environment. The technique makes use of hidden Markov models and we demonstrate its application for estimating a crucial parameter in the oil industry. We then focus on hybrid models that we call dynamical local models. These models combine and generalise hidden Markov models and state space models. Probabilistic inference is unfortunately computationally intractable and we show how to make use of variational techniques for approximating the posterior distribution over the hidden state variables. Experimental simulations on synthetic and real-world data demonstrate the application of dynamical local models for segmenting a time series into regimes and providing predictive distributions.

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This thesis examines the predictive value of a conceptual distinction between status-seeking associations and status-maintaining associations for enhancing understanding of ten selected professional associations and of the attitudes, values, behaviour and policies of their governing organs. Thirty four specific hypotheses have been tested by such research methods as questionnaires administered to individuals and associations, participant observation and an examination of association minutes and publications. Certain hypotheses have been found to be valid for particular matched pairs and/or groups of associations. The findings of the study suggest that the present conceptualisation of profession, the individual professional, professionalism, professionalisation, professional status and that relating to the role of the professions in society needs to be refined and modified in varying degrees in application to accounting associations, business graduate associations and management associations. The concept of the `ideal type' profession is shown to be of limited value in understanding certain aspects of the activities of business graduate and management associations. The findings of the study suggest that in future the professional associations examined may attach less importance to their qualifying role and lay more stress upon their representational role. The professional association faces a managerial challenge to adjust and adapt to a range of `external' pressures and `internal' demands from members and may increasingly need to be regarded as an organisation that possesses certain combinations or sets of characteristics rather than as a type of organisation that possesses a particular or relatively exclusive set. With a blurring of the distinction between the professional and state sector vocational education, and a growing customer/market orientation associated with the changing nature of work, membership of a professional association may, in future, come to be associated rather more with securing access to a relevant range of services and less with qualification for a particular career.

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To ensure state synchronization of signalling operations, many signaling protocol designs choose to establish “soft” state that expires if it is not refreshed. The approaches of refreshing state in multi-hop signaling system can be classified as either end-to-end (E2E) or hop-by-hop (HbH). Although both state refresh approaches have been widely used in practical signaling protocols, the design tradeoffs between state synchronization and signaling cost have not yet been fully investigated. In this paper, we investigate this issue from the perspectives of state refresh and state removal. We propose simple but effective Markov chain models for both approaches and obtain closed-form solutions which depict the state refresh performance in terms of state consistency and refresh message rate, as well as the state removal performance in terms of state removal delay. Simulations verify the analytical models. It is observed that the HbH approach yields much better state synchronization at the cost of higher signaling cost than the E2E approach. While the state refresh performance can be improved by increasing the values of state refresh and timeout timers, the state removal delay increases largely for both E2E and HbH approaches. The analysis here shed lights on the design of signaling protocols and the configuration of the timers to adapt to changing network conditions.

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Past studies resulted in conflicting definitions of consumer motivation. Motivations are seen either as the consumer? s characteristics that shape her general behavior (motivational trait), or as contextual variables representing the reason why the individual is behaving specific to today?s context (motivational state). The objective of this research is to understand the impact of each on consumer behavior. Applied to shopping motivations, our study shows a strong interaction between motivational trait and state: motivational traits influence behavior only when associated with a recreational motivational state. In a functional motivational state, individuals prevent their personal characteristics from being fully expressed.

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According to the textbook approach, the developmental states of the Far East have been considered as strong and autonomous entities. Although their bureaucratic elites have remained isolated from direct pressures stemming from society, the state capacity has also been utilised in order to allocate resources in the interest of the whole society. Yet, society – by and large –has remained weak and subordinated to the state elite. On the other hand, the general perception of Sub-Saharan Africa (SSA) has been just the opposite. The violent and permanent conflict amongst rent-seeking groups for influence and authority over resources has culminated in a situation where states have become extremely weak and fragmented, while society – depending on the capacity of competing groups for mobilising resources to organise themselves mostly on a regional or local level (resulting in local petty kingdoms) – has never had the chance to evolve as a strong player. State failure in the literature, therefore, – in the context of SSA – refers not just to a weak and captured state but also to a non-functioning, and sometimes even non-existent society, too. Recently, however, the driving forces of globalisation might have triggered serious changes in the above described status quo. Accordingly, our hypothesis is the following: globalisation, especially the dynamic changes of technology, capital and communication have made the simplistic “strong state–weak society” (in Asia) and “weak state–weak society” (in Africa) categorisation somewhat obsolete. While our comparative study has a strong emphasis on the empirical scrutiny of trying to uncover the dynamics of changes in state–society relations in the two chosen regions both qualitatively and quantitatively, it also aims at complementing the meaning and essence of the concepts and methodology of stateness, state capacity and state-society relations, the well-known building blocks of the seminal works of Evans (1995), Leftwich (1995), Migdal (1988) or Myrdal (1968).

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Based on extensive quantitative and qualitative analyses of a corpus of American presidential speeches that includes all inaugural addresses and State of the Union messages from 1789 to 2008, as well as major foreign and security policy speeches after 1945, this research monograph analyzes the various forms and functions of intertextual references found in the discourse of American presidents. Working within an original, interdisciplinary theoretical framework established by theories of intertextuality, discourse analysis, and presidential studies, the book discusses five different types of presidential intertextuality, all of which contribute jointly to creating a set of carefully manipulated and politically powerful images of both the American nation and the American presidency. The book is intended for scholars and students in political and presidential studies, communications, American cultural studies, and linguistics, as well as anyone interested in the American presidency in general.