994 resultados para Form Error Compensation


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In terrestrial television transmission multiple paths of various lengths can occur between the transmitter and the receiver. Such paths occur because of reflections from objects outside the direct transmission path. The multipath signals arriving at the receiver are all detected along with the intended signal causing time displaced replicas called 'ghosts' to appear on the television picture. With an increasing number of people living within built up areas, ghosting is becoming commonplace and therefore deghosting is becoming increasingly important. This thesis uses a deterministic time domain approach to deghosting, resulting in a simple solution to the problem of removing ghosts. A new video detector is presented which reduces the synchronous detector local oscillator phase error, caused by any practical size of ghost, to a lower level than has ever previously been achieved. From the new detector, dispersion of the video signal is minimised and a known closed-form time domain description of the individual ghost components within the detected video is subsequently obtained. Developed from mathematical descriptions of the detected video, a new specific deghoster filter structure is presented which is capable of removing both inphase (I) and also the phase quadrature (Q) induced ghost signals derived from the VSB operation. The new deghoster filter requires much less hardware than any previous deghoster which is capable of removing both I and Q ghost components. A new channel identification algorithm was also required and written which is based upon simple correlation techniques to find the delay and complex amplitude characteristics of individual ghosts. The result of the channel identification is then passed to the new I and Q deghoster filter for ghost cancellation. Generated from the research work performed for this thesis, five papers have been published. D

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Risk and uncertainty are, to say the least, poorly considered by most individuals involved in real estate analysis - in both development and investment appraisal. Surveyors continue to express 'uncertainty' about the value (risk) of using relatively objective methods of analysis to account for these factors. These methods attempt to identify the risk elements more explicitly. Conventionally this is done by deriving probability distributions for the uncontrolled variables in the system. A suggested 'new' way of "being able to express our uncertainty or slight vagueness about some of the qualitative judgements and not From its modern origins, associated with the urbanising effect of industrialisation, walking has remained a popular form of outdoor recreation. It has, furthermore, remained an important site of class struggle, with the 'landless' seeking to establish their moral 'citizen' right to roam over open country in contradistinction to the 'landed', who have successfully limited this right to legally-defined public rights of way. In the face of declining farm incomes, however, farmers and landowners have, apparently, modified their attitudes towards public access, but only in return for compensation and management payments under grant schemes such as Countryside Stewardship and the Countryside Premium Scheme. With the Ministry of Agriculture, Fisheries and Food now seeking to extend paid access arrangements to other grant schemes, as part of its response to the European Union's Agri-Environment Regulations, access 'rights' are assuming an increasingly commodified form, thereby questioning, if not undermining, the former citizen claims. For rather than being a benefit of citizenship, the existence of limited, often poorly maintained and inadequately signposted, public rights of way has tied inextricably the extension of legally-enforceable access to the needs of the landowners and farmers. At a time of falling prosperity in agriculture, therefore, they have now exercised their discretion by annexing the populism of consumer culture to reproduce the bourgeois liberal values of the market as a principal determinant of the extension of citizen rights of access to the countryside.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper examines the evolution of public rights of access to private land in England and Wales. Since the Eighteenth Century the administration and protection of these rights has been though a form of public/private partnership in which the judiciary, while maintaining the dominance of private property, have safeguarded de facto public access by refusing consistently to punish simple trespass. While this situation has been modified, principally by post-World War II legislation, to allow for some formalisation of access arrangements and consequent compensation to landowners in areas of high recreational pressure and low legal accessibility, recent policy initiatives suggest that the balance of the partnership has now shifted in favour of landowners. In particular, the new access payment schemes, developed by the UK Government in response to the European Commission's Agri-Environment Regulations, locate the landowner as the beneficiary of the partnership, financed by tax revenue and justified on the spurious basis of improved 'access provision'. As such the state, as the former upholder of citizen rights, now assumes the duplicitous position of underwriting private property ownership through the commodification of access, while proclaiming a significant improvement in citizens' access rights.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper examines the evolution of public rights of access to private land in England and Wales. Since the Eighteenth Century the administration and protection of these rights has been though a form of public/private partnership in which the judiciary, while maintaining the dominance of private property, have safeguarded de facto public access by refusing consistently to punish simple trespass. While this situation has been modified, principally by post-World War II legislation, to allow for some formalisation of access arrangements and consequent compensation to landowners in areas of high recreational pressure and low legal accessibility, recent policy initiatives suggest that the balance of the partnership has now shifted in favour of landowners. In particular, the new access payment schemes, developed by the UK Government in response to the European Commission's Agri-Environment Regulations, identify the landowner as the beneficiary of the partnership, financed by tax revenue and justified on the spurious basis of improved 'access provision'. As such the State, as the former upholder of citizen rights, now assumes the duplicitous position of underwriting private property ownership through the commodification of access, while proclaiming a significant improvement in citizens' access rights.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper proposes hybrid capital securities as a significant part of senior bank executive incentive compensation in light of Basel III, a new global regulatory standard on bank capital adequacy and liquidity agreed by the members of the Basel Committee on Banking Supervision. The committee developed Basel III in a response to the deficiencies in financial regulation brought about by the global financial crisis. Basel III strengthens bank capital requirements and introduces new regulatory requirements on bank liquidity and bank leverage. The hybrid bank capital securities we propose for bank executives’ compensation are preferred shares and subordinated debt that the June 2004 Basel II regulatory framework recognised as other admissible forms of capital. The past two decades have witnessed dramatic increase in performance-related pay in the banking industry. Stakeholders such as shareholders, debtholders and regulators criticise traditional cash and equity-based compensation for encouraging bank executives’ excessive risk taking and short-termism, which has resulted in the failure of risk management in high profile banks during the global financial crisis. Paying compensation in the form of hybrid bank capital securities may align the interests of executives with those of stakeholders and help banks regain their reputation for prudence after years of aggressive risk-taking. Additionally, banks are desperately seeking to raise capital in order to bolster balance sheets damaged by the ongoing credit crisis. Tapping their own senior employees with large incentive compensation packages may be a viable additional source of capital that is politically acceptable in times of large-scale bailouts of the financial sector and economically wise as it aligns the interests of the executives with the need for a stable financial system.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An active pharmaceutical ingredient (API) was found to dissociate from the highly crystalline hydrochloride form to the amorphous free base form, with consequent alterations to tablet properties. Here, a wet granulation manufacturing process has been investigated using in situ Fourier transform (FT)-Raman spectroscopic analyses of granules and tablets prepared with different granulating fluids and under different manufacturing conditions. Dosage form stability under a range of storage stresses was also investigated. Despite the spectral similarities between the two drug forms, low levels of API dissociation could be quantified in the tablets; the technique allowed discrimination of around 4% of the API content as the amorphous free base (i.e. less than 1% of the tablet compression weight). API dissociation was shown to be promoted by extended exposure to moisture. Aqueous granulating fluids and manufacturing delays between granulation and drying stages and storage of the tablets in open conditions at 40◦C/75% relative humidity (RH) led to dissociation. In contrast, non-aqueous granulating fluids, with no delay in processing and storage of the tablets in either sealed containers or at lower temperature/humidity prevented detectable dissociation. It is concluded that appropriate manufacturing process and storage conditions for the finished product involved minimising exposure to moisture of the API. Analysis of the drug using FT-Raman spectroscopy allowed rapid optimisation of the process whilst offering quantitative molecular information concerning the dissociation of the drug salt to the amorphous free base form.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Assimilation of temperature observations into an ocean model near the equator often results in a dynamically unbalanced state with unrealistic overturning circulations. The way in which these circulations arise from systematic errors in the model or its forcing is discussed. A scheme is proposed, based on the theory of state augmentation, which uses the departures of the model state from the observations to update slowly evolving bias fields. Results are summarized from an experiment applying this bias correction scheme to an ocean general circulation model. They show that the method produces more balanced analyses and a better fit to the temperature observations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Data assimilation aims to incorporate measured observations into a dynamical system model in order to produce accurate estimates of all the current (and future) state variables of the system. The optimal estimates minimize a variational principle and can be found using adjoint methods. The model equations are treated as strong constraints on the problem. In reality, the model does not represent the system behaviour exactly and errors arise due to lack of resolution and inaccuracies in physical parameters, boundary conditions and forcing terms. A technique for estimating systematic and time-correlated errors as part of the variational assimilation procedure is described here. The modified method determines a correction term that compensates for model error and leads to improved predictions of the system states. The technique is illustrated in two test cases. Applications to the 1-D nonlinear shallow water equations demonstrate the effectiveness of the new procedure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We consider the two-point boundary value problem for stiff systems of ordinary differential equations. For systems that can be transformed to essentially diagonally dominant form with appropriate smoothness conditions, a priori estimates are obtained. Problems with turning points can be treated with this theory, and we discuss this in detail. We give robust difference approximations and present error estimates for these schemes. In particular we give a detailed description of how to transform a general system to essentially diagonally dominant form and then stretch the independent variable so that the system will satisfy the correct smoothness conditions. Numerical examples are presented for both linear and nonlinear problems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents novel observer-based techniques for the estimation of flow demands in gas networks, from sparse pressure telemetry. A completely observable model is explored, constructed by incorporating difference equations that assume the flow demands are steady. Since the flow demands usually vary slowly with time, this is a reasonable approximation. Two techniques for constructing robust observers are employed: robust eigenstructure assignment and singular value assignment. These techniques help to reduce the effects of the system approximation. Modelling error may be further reduced by making use of known profiles for the flow demands. The theory is extended to deal successfully with the problem of measurement bias. The pressure measurements available are subject to constant biases which degrade the flow demand estimates, and such biases need to be estimated. This is achieved by constructing a further model variation that incorporates the biases into an augmented state vector, but now includes information about the flow demand profiles in a new form.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The problem of calculating the probability of error in a DS/SSMA system has been extensively studied for more than two decades. When random sequences are employed some conditioning must be done before the application of the central limit theorem is attempted, leading to a Gaussian distribution. The authors seek to characterise the multiple access interference as a random-walk with a random number of steps, for random and deterministic sequences. Using results from random-walk theory, they model the interference as a K-distributed random variable and use it to calculate the probability of error in the form of a series, for a DS/SSMA system with a coherent correlation receiver and BPSK modulation under Gaussian noise. The asymptotic properties of the proposed distribution agree with other analyses. This is, to the best of the authors' knowledge, the first attempt to propose a non-Gaussian distribution for the interference. The modelling can be extended to consider multipath fading and general modulation