920 resultados para fidelity of implementation
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Federal Highway Administration, Office of Implementation, Washington, D.C.
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We demonstrate a quantum error correction scheme that protects against accidental measurement, using a parity encoding where the logical state of a single qubit is encoded into two physical qubits using a nondeterministic photonic controlled-NOT gate. For the single qubit input states vertical bar 0 >, vertical bar 1 >, vertical bar 0 > +/- vertical bar 1 >, and vertical bar 0 > +/- i vertical bar 1 > our encoder produces the appropriate two-qubit encoded state with an average fidelity of 0.88 +/- 0.03 and the single qubit decoded states have an average fidelity of 0.93 +/- 0.05 with the original state. We are able to decode the two-qubit state (up to a bit flip) by performing a measurement on one of the qubits in the logical basis; we find that the 64 one-qubit decoded states arising from 16 real and imaginary single-qubit superposition inputs have an average fidelity of 0.96 +/- 0.03.
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Cyclin-dependent kinase 4 (CDK4)/cyclin D has a key role in regulating progression through late G(1) into S phase of the cell cycle. CDK4-cyclin D complexes then persist through the latter phases of the cell cycle, although little is known about their potential roles. We have developed small molecule inhibitors that are highly selective for CDK4 and have used these to define a role for CDK4-cyclin D in G(2) phase. The addition of the CDK4 inhibitor or small interfering RNA knockdown of cyclin D3, the cyclin D partner, delayed progression through G(2) phase and mitosis. The G(2) phase delay was independent of ATM/ATR and p38 MAPK but associated with elevated Wee1. The mitotic delay was because of failure of chromosomes to migrate to the metaphase plate. However, cells eventually exited mitosis, with a resultant increase in cells with multiple or micronuclei. Inhibiting CDK4 delayed the expression of the chromosomal passenger proteins survivin and borealin, although this was unlikely to account for the mitotic phenotype. These data provide evidence for a novel function for CDK4-cyclin D3 activity in S and G(2) phase that is critical for G(2)/M progression and the fidelity of mitosis.
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Public policy becomes managerial practice through a process of implementation. There is an established literature within Implementation Studies which explains the variables and some of the processes involved in implementation, but less attention has been focused upon how public service managers convert new policy initiatives into practice. The research proposes that managers and their organisations have to go through a process of learning in order to achieve the implementation of public policy. Data was collected over a five year period from four case studies of capital investment appraisal in the British National Health Service. Further data was collected from taped interviews by key actors within the case studies. The findings suggest that managers do learn to implement policy and four factors are important in this learning process. These are; (i) the nature of bureaucratic responsibility; (ii) the motivation of actors towards learning; (iii) the passage of time which allows for the development of competence and (iv) the use of project team structures. The research has demonstrated that the conversion of policy into practice occurs through the operationalisation of solutions to policy problems via job tasks. As such it suggests that in understanding how policy is implemented, technical learning is more important than cultural learning, in this context. In conclusion, a "Model of Learned Implementation" is presented, together with a discussion of some of the implications of the research. These are the possible use of more pilot projects for new policy initiatives and the more systematic diffusion of knowledge about implementation solutions.
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The growth and advances made in computer technology have led to the present interest in picture processing techniques. When considering image data compression the tendency is towards trans-form source coding of the image data. This method of source coding has reached a stage where very high reductions in the number of bits representing the data can be made while still preserving image fidelity. The point has thus been reached where channel errors need to be considered, as these will be inherent in any image comnunication system. The thesis first describes general source coding of images with the emphasis almost totally on transform coding. The transform technique adopted is the Discrete Cosine Transform (DCT) which becomes common to both transform coders. Hereafter the techniques of source coding differ substantially i.e. one technique involves zonal coding, the other involves threshold coding. Having outlined the theory and methods of implementation of the two source coders, their performances are then assessed first in the absence, and then in the presence, of channel errors. These tests provide a foundation on which to base methods of protection against channel errors. Six different protection schemes are then proposed. Results obtained, from each particular, combined, source and channel error protection scheme, which are described in full are then presented. Comparisons are made between each scheme and indicate the best one to use given a particular channel error rate.
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The research investigates the processes of adoption and implementation, by organisations, of computer aided production management systems (CAPM). It is organised around two different theoretical perspectives. The first part is informed by the Rogers model of the diffusion, adoption and implementation of innovations, and the second part by a social constructionist approach to technology. Rogers' work is critically evaluated and a model of adoption and implementation is distilled from it and applied to a set of empirical case studies. In the light of the case study data, strengths and weaknesses of the model are identified. It is argued that the model is too rational and linear to provide an adequate explanation of adoption processes. It is useful for understanding processes of implementation but requires further development. The model is not able to adequately encompass complex computer based technologies. However, the idea of 'reinvention' is identified as Roger's key concept but it needs to be conceptually extended. Both Roger's model and definition of CAPM found in the literature from production engineering tend to treat CAPM in objectivist terms. The problems with this view are addressed through a review of the literature on the sociology of technology, and it is argued that a social constructionist approach offers a more useful framework for understanding CAPM, its nature, adoption, implementation, and use. CAPM it is argued, must be understood on terms of the ways in which it is constituted in discourse, as part of a 'struggle for meaning' on the part of academics, professional engineers, suppliers, and users.
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Objective - To evaluate behavioural components and strategies associated with increased uptake and effectiveness of screening for coronary heart disease and diabetes with an implementation science focus. Design - Realist review. Data sources - PubMed, Web of Knowledge, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register and reference chaining. Searches limited to English language studies published since 1990. Eligibility criteria - Eligible studies evaluated interventions designed to increase the uptake of cardiovascular disease (CVD) and diabetes screening and examined behavioural and/or strategic designs. Studies were excluded if they evaluated changes in risk factors or cost-effectiveness only. Results - In 12 eligible studies, several different intervention designs and evidence-based strategies were evaluated. Salient themes were effects of feedback on behaviour change or benefits of health dialogues over simple feedback. Studies provide mixed evidence about the benefits of these intervention constituents, which are suggested to be situation and design specific, broadly supporting their use, but highlighting concerns about the fidelity of intervention delivery, raising implementation science issues. Three studies examined the effects of informed choice or loss versus gain frame invitations, finding no effect on screening uptake but highlighting opportunistic screening as being more successful for recruiting higher CVD and diabetes risk patients than an invitation letter, with no differences in outcomes once recruited. Two studies examined differences between attenders and non-attenders, finding higher risk factors among non-attenders and higher diagnosed CVD and diabetes among those who later dropped out of longitudinal studies. Conclusions - If the risk and prevalence of these diseases are to be reduced, interventions must take into account what we know about effective health behaviour change mechanisms, monitor delivery by trained professionals and examine the possibility of tailoring programmes according to contexts such as risk level to reach those most in need. Further research is needed to determine the best strategies for lifelong approaches to screening.
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The purpose of this inquiry was to investigate the impact of a large, urban school district's experience in implementing a mandated school improvement plan and to examine how that plan was perceived, interpreted, and executed by those charged with the task. The research addressed the following questions: First, by whom was the district implementation plan designed, and what factors were considered in its construction? Second, what impact did the district implementation plan have on those charged with its implementation? Third, what impact did the district plan have on the teaching and learning practices of a particular school? Fourth, what aspects of the implemention plan were perceived as most and least helpful by school personnel in achieving stated goals? Last, what were the intended and unintended consequences of an externally mandated and directed plan for improving student achievement? The implementation process was measured against Fullan's model as expounded upon in The Meaning of Educational Change (1982) and The New Meaning of Educational Change (1990). The Banya implementation model (1993), because it added a dimension not adequately addressed by Fullan, was also considered.^ A case study was used as the methodological framework of this qualitative study. Sources of data used in this inquiry included document analysis, participant observations in situ, follow-up interviews, the "long" interview, and triangulation. The study was conducted over a twelve-month period. Findings were obtained from the content analysis of interview transcripts of multiple participants. Results were described and interpreted using the Fullan and Banya models as the descriptive framework. A cross-case comparison of the multiple perspectives of the same phenomena by various participants was constructed.^ The study concluded that the school district's implementation plan to improve student achievement was closely aligned to Fullan's model, although not intentionally. The research also showed that where there was common understanding at all levels of the organization as to the expectations for teachers, level of support to be provided, and availability of resources, successful implementation occured. The areas where successful implementation did not occur were those where the complexity of the changes were underestimated and processes for dealing with unintended consequences were not considered or adequately addressed. The unique perspectives of the various participants, from the superintendent to the classroom teacher, are described. Finally, recommendations for enhancement of implementation are offered and possible topics for further research studies are postulated. ^
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Policy/program implementation, e.g., the process of fulfilling policy/program directives, is fundamentally tied to change. Implementation studies have examined the process, identifying many critical organizational variables although individuals perform the activities.^ Many of the studies are predicated on the rational, goal oriented model of organizations and examine implementation, presenting only the goal-oriented view. Organizational change and its resistance, however, are not fully explained by the rational model of organizations. There are other schools of thought providing different views of organizations from which explanation may emerge. Bolman and Deal (1984, 1991a, 1994) provide a different perspective for examining organizations Bolman and Deal argue organizations should be viewed through four different frames or lenses. Framing and reframing organizational action captures the complexity of action and provides better understanding of organizational processes. Understanding of implementation of policies/programs also will benefit from the use of the four-frame approach.^ The goal of this research is to provide a better understanding of the implementation process by examining individual attitudes toward change, the dependent variable of this research, and studying the relationship between the dependent variable and frame. The research was conducted in two phases. In Phase One, a survey was sent to 306 school administrators and teachers in magnet programs in Dade County, Florida. The survey instrument was composed of 55 questions including six from Bolman and Deal's Leadership Orientation Survey (1988) and 38 questions about organizational change. In Phase Two, more in-depth analysis of four school was conducted, to further explore the relationship between frame and attitude toward change.^ The results revealed that frame was a factor in explaining differences in personal Attitude Toward Change and Comfort Level with Change. Individuals using the symbolic frame had more positive attitudes toward change and were also more comfortable with change. The results of Phase Two of the research partially supported this finding in that the most fully implemented program was the product of an administrator who had chosen the symbolic frame. ^
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Prevention scientists have called for more research on the factors affecting the implementation of substance use prevention programs. Given the lack of literature in this area, coupled with evidence that children as early as elementary school engage in substance use, the purpose of this study was to identify the factors that influence the implementation of substance use prevention programs in elementary schools. This study involved a mixed methods approach comprised of a survey and in-person interviews. Sixty-five guidance counselors and teachers completed the survey, and 9 guidance counselors who completed the survey were interviewed individually. Correlation analyses and hierarchical multiple regression were conducted. Quantitative findings revealed ease of implementation most frequently influenced program implementation, followed by beliefs about the program's effectiveness. Qualitative findings showed curriculum modification as an important theme, as well as difficulty of program implementation. The in-person interviews also shed light on three interrelated themes influencing program implementation – The Wheel, time, and scheduling. Results indicate the majority of program providers modified the curriculum in some way. Implications for research, policy, and practice are discussed, and areas for future research are suggested.^
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[EN] Sea turtles exhibit a strong natal homing associated with a high nesting site philopatry. Mark-recapture and genetic studies confirm these patterns suggesting differences among and within species. In the present study, we have analysed the degree of nest site fidelity of a loggerhead population nesting on the islands of Cape Verde and have evaluated the existence of intrapopulational variability in this trait. The loggerhead is the only sea turtle species that nests in Cape Verde, and 15,000–25,000 nests per season have been estimated for the whole archipelago.
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Prevention scientists have called for more research on the factors affecting the implementation of substance use prevention programs. Given the lack of literature in this area, coupled with evidence that children as early as elementary school engage in substance use, the purpose of this study was to identify the factors that influence the implementation of substance use prevention programs in elementary schools. This study involved a mixed methods approach comprised of a survey and in-person interviews. Sixty-five guidance counselors and teachers completed the survey, and 9 guidance counselors who completed the survey were interviewed individually. Correlation analyses and hierarchical multiple regression were conducted. Quantitative findings revealed ease of implementation most frequently influenced program implementation, followed by beliefs about the program’s effectiveness. Qualitative findings showed curriculum modification as an important theme, as well as difficulty of program implementation. The in-person interviews also shed light on three interrelated themes influencing program implementation – The Wheel, time, and scheduling. Results indicate the majority of program providers modified the curriculum in some way. Implications for research, policy, and practice are discussed, and areas for future research are suggested.
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We present a scheme for quasiperfect transfer of polariton states from a sender to a spatially separated receiver, both composed of high-quality cavities filled by atomic samples. The sender and the receiver are connected by a nonideal transmission channel -the data bus- modelled by a network of lossy empty cavities. In particular, we analyze the influence of a large class of data-bus topologies on the fidelity and transfer time of the polariton state. Moreover, we also assume dispersive couplings between the polariton fields and the data-bus normal modes in order to achieve a tunneling-like state transfer. Such a tunneling-transfer mechanism, by which the excitation energy of the polariton effectively does not populate the data-bus cavities, is capable of attenuating appreciably the dissipative effects of the data-bus cavities. After deriving a Hamiltonian for the effective coupling between the sender and the receiver, we show that the decay rate of the fidelity is proportional to a cooperativity parameter that weighs the cost of the dissipation rate against the benefit of the effective coupling strength. The increase of the fidelity of the transfer process can be achieved at the expense of longer transfer times. We also show that the dependence of both the fidelity and the transfer time on the network topology is analyzed in detail for distinct regimes of parameters. It follows that the data-bus topology can be explored to control the time of the state-transfer process.
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In this paper we detail some results advanced in a recent letter [Prado et al., Phys. Rev. Lett. 102, 073008 (2009).] showing how to engineer reservoirs for two-level systems at absolute zero by means of a time-dependent master equation leading to a nonstationary superposition equilibrium state. We also present a general recipe showing how to build nonadiabatic coherent evolutions of a fermionic system interacting with a bosonic mode and investigate the influence of thermal reservoirs at finite temperature on the fidelity of the protected superposition state. Our analytical results are supported by numerical analysis of the full Hamiltonian model.
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We analyze the dynamical behavior of a quantum system under the actions of two counteracting baths: the inevitable energy draining reservoir and, in opposition, exciting the system, an engineered Glauber's amplifier. We follow the system dynamics towards equilibrium to map its distinctive behavior arising from the interplay of attenuation and amplification. Such a mapping, with the corresponding parameter regimes, is achieved by calculating the evolution of both the excitation and the Glauber-Sudarshan P function. Techniques to compute the decoherence and the fidelity of quantum states under the action of both counteracting baths, based on the Wigner function rather than the density matrix, are also presented. They enable us to analyze the similarity of the evolved state vector of the system with respect to the original one, for all regimes of parameters. Applications of this attenuation-amplification interplay are discussed.