Practical stability of approximating discrete-time filters with respect to model mismatch using relative entropy concepts

This paper establishes practical stability results for an important range of approximate discrete-time filtering problems involving mismatch between the true system and the approximating filter model. Using local consistency assumption, the practical stability established is in the sense of an asymptotic bound on the amount of bias introduced by the model approximation. Significantly, these practical stability results do not require the approximating model to be of the same model type as the true system. Our analysis applies to a wide range of estimation problems and justifies the common practice of approximating intractable infinite dimensional nonlinear filters by simpler computationally tractable filters.

Fat and thin adaptive HMM filters for vision based detection of moving targets

Computer vision is an attractive solution for uninhabited aerial vehicle (UAV) collision avoidance, due to the low weight, size and power requirements of hardware. A two-stage paradigm has emerged in the literature for detection and tracking of dim targets in images, comprising of spatial preprocessing, followed by temporal filtering. In this paper, we investigate a hidden Markov model (HMM) based temporal filtering approach. Specifically, we propose an adaptive HMM filter, in which the variance of model parameters is refined as the quality of the target estimate improves. Filters with high variance (fat filters) are used for target acquisition, and filters with low variance (thin filters) are used for target tracking. The adaptive filter is tested in simulation and with real data (video of a collision-course aircraft). Our test results demonstrate that our adaptive filtering approach has improved tracking performance, and provides an estimate of target heading not present in previous HMM filtering approaches.

Driving speed is altered by monocular Neutral Density filters : the Enright phenomenon

Introduction: An observer, looking sideways from a moving vehicle, while wearing a neutral density filter over one eye, can have a distorted perception of speed, known as the Enright phenomenon. The purpose of this study was to determine how the Enright phenomenon influences driving behaviour. Methods: A geometric model of the Enright phenomenon was developed. Ten young, visually normal, participants (mean age = 25.4 years) were tested on a straight section of a closed driving circuit and instructed to look out of the right side of the vehicle and drive at either 40 Km/h or 60 Km/h under the following binocular viewing conditions: with a 0.9 ND filter over the left eye (leading eye); 0.9 ND filter over the right eye (trailing eye); 0.9 ND filters over both eyes, and with no filters over either eye. The order of filter conditions was randomised and the speed driven recorded for each condition. Results: Speed judgments did not differ significantly between the two baseline conditions (no filters and both eyes filtered) for either speed tested. For the baseline conditions, when subjects were asked to drive at 60 Km/h they matched this speed well (61 ± 10.2 Km/h) but drove significantly faster than requested (51.6 ± 9.4 Km/h) when asked to drive at 40 Km/h. Subjects significantly exceeded baseline speeds by 8.7± 5.0 Km/h, when the trailing eye was filtered and travelled slower than baseline speeds by 3.7± 4.6 Km/h when the leading eye was filtered. Conclusions: This is the first quantitative study demonstrating how the Enright effect can influence perceptions of driving speed, and demonstrates that monocular filtering of an eye can significantly impact driving speeds, albeit to a lesser extent than predicted by geometric models of the phenomenon.

Taxation of multinational banks : using formulary apportionment to reflect economic reality (Part 1)

Formulary apportionment does not attempt to undertake a transactional division of a highly integrated multinational entity. Rather, it allocates income to the jurisdictions based on an economically justifiable formula. Opposition to formulary apportionment is generally based on the argument that it is not a theoretically superior (or optimal) model because of the implementation difficulties. The conclusion that the unitary taxation model may be theoretically superior to the current arm's-length model that applies to multinational banks, despite significant implementation, compliance, and enforcement issues, is based on the unitary taxation model providing greater alignment with the unique features of these banks. The formulary apportionment model looks to the economic substance of the multinational entity and, in this sense, adopts a substance-over- form approach. Formulary apportionment further recognizes the impossibility of using arm's-length pricing for economically interdependent multinational entities. A final advantage to formulary apportionment, which is also a consequence of this model achieving greater inter-nation equity, is the elimination of double taxation.

The taxation of multinational banks : alternative apportionment through a unitary taxation regime aligning with economic reality

The taxation of multinational banks currently is governed by the general principles of international tax. However, it is arguable that there are characteristics exclusive to multinational banks that may warrant the consideration of a separate taxing regime. This article argues that because of the unique nature of multinational banks, the traditional international tax rules governing jurisdiction to tax and allocation of income do not produce a result which is optimal, as it does not reflect economic reality. That is, the current system does not produce a result that accurately reflects the economic source of the income or the location of the economic activity. The suggested alternative is unitary taxation using global formulary apportionment. Formulary apportionment is considered as an alternative that reflects economic reality by recognising the unique nature of multinational banks and allocating the income to the location of the economic activity. The unique nature of multinational banking is recognised in the fact that formulary apportionment does not attempt to undertake a transactional division of a highly integrated multinational entity. Rather, it allocates income to the jurisdictions based on an economically justifiable formula. Starting from this recognition, the purpose of this article is to demonstrate that formulary apportionment is a theoretically superior (or optimal) model for the taxation of multinational banks. An optimal regime, for the purposes of this article, is considered to be one that distributes the taxing rights in an equitable manner between the relevant jurisdictions, while, simultaneously allowing decisions of the international banks to be tax neutral. In this sense, neutrality is viewed as an economic concept and equity is regarded as a legal concept. A neutral tax system is one in which tax rules do not affect economic choices about commercial activities. Neutrality will ideally be across jurisdictions as well as across traditional and non-traditional industries. The primary focus of this article is jurisdictional neutrality. A system that distributes taxing rights in an equitable manner between the relevant jurisdictions ensures that each country receives its fair share of tax revenue. Given the increase in multinational banking, jurisdictions should be concerned that they are receiving their fair share. Inter-nation equity is concerned with re-determining the proper division of the tax base among countries. Richard and Peggy Musgrave argue that sharing of the tax base by countries of source should be seen as a matter of inter-nation equity requiring international cooperation. The rights of the jurisdiction of residency will also be at issue. To this extent, while it is agreed that inter-nation equity is an essential attribute to an international tax regime, there is no universal agreement as to how to achieve it. The current system attempts to achieve such equity through a combined residency and source regime, with the transfer pricing rules used to apportion income between the relevant jurisdictions. However, this article suggests, that as an alternative to the current regime, equity would be achieved through formulary apportionment. Opposition to formulary apportionment is generally based on the argument that it is not a theoretically superior (or optimal) model because of the implementation difficulties. Yet these are two separate issues. As such, this article is divided into two core parts. The first part examines the theoretical soundness of the formulary apportionment model concluding that it is theoretically superior to the arm’s length pricing requirement of the traditional transfer pricing regime. The second part examines the practical implications of accepting formulary apportionment as an optimal model with a view to disclosing the issues that arise when a formulary apportionment regime is adopted. Prior to an analysis of the theoretical and practical application of formulary apportionment to multinational banks, the unique nature of these banks is considered. The article concludes that, while there are significant implementation, compliance, and enforcement issues to overcome, the unitary taxation model may be theoretically superior to the current arm’s length model which applies to multinational banks. This conclusion is based on the unitary taxation model providing greater alignment with the unique features of these banks.

Taxation of multinational banks : using formulary apportionment to reflect economic reality (Part 2)

As stated in Part 1 of this article, formulary appointment does not attempt to undertake a transactional division of a highly integrated multinational entity; rather, it allocates income to the jurisdictions based on economically justifiable formula. This article argues that the unitary taxation model is superior to the current arms-lenght model for the taxation of multinational banks despite significant implementation, complicance and enforcement issues. Part one of the article gave some background on the taxation of multinational banks, followed by a discussion of their uniqueness, and the theoretical benefits of the unitary tax model for multinational banking. Part 2 below covers the practical implications of accepting formulary apportionment as an 'optimal' regime for taxing multinational banks.

Relative entropy rate based model selection for linear hybrid system filters of uncertain nonlinear systems

Hybrid system representations have been exploited in a number of challenging modelling situations, including situations where the original nonlinear dynamics are too complex (or too imprecisely known) to be directly filtered. Unfortunately, the question of how to best design suitable hybrid system models has not yet been fully addressed, particularly in the situations involving model uncertainty. This paper proposes a novel joint state-measurement relative entropy rate based approach for design of hybrid system filters in the presence of (parameterised) model uncertainty. We also present a design approach suitable for suboptimal hybrid system filters. The benefits of our proposed approaches are illustrated through design examples and simulation studies.

Taxation of multinational banks : using formulary apportionment to reflect economic reality

The taxation of multinational banks is currently governed by general principles of international tax. However, there are characteristics exclusive to multinational banks that may warrant consideration of a separate taxing regime, as the current system does not produce a result that accurately reflects the economic source of the income or the location of the economic activity. The suggested alternative is unitary taxation using global formulary apportionment.

More food banks than MacDonalds : the future of civil society?

The title of this paper came out of a conversation I had on a recent trip to Canada. I had gone there because I wanted to spend a bit of time seeing how non-government organisations in Canada were faring in this age of re inventing government. Osborne and Gaebler (1992) I wanted to try and understand whether there were any lessons in the Canadian experience, that might be relevant for Australia. As I hope to demonstrate while there are both similarities and differences, the questions facing both nations have a remarkable correspondence.

Practical stability of approximating discrete-time filters with respect to model mismatch

This paper establishes practical stability results for an important range of approximate discrete-time filtering problems involving mismatch between the true system and the approximating filter model. Practical stability is established in the sense of an asymptotic bound on the amount of bias introduced by the model approximation. Our analysis applies to a wide range of estimation problems and justifies the common practice of approximating intractable infinite dimensional nonlinear filters by simpler computationally tractable filters.

Alternatives to the World Bank’s strategies for education and development

Over the past several decades, policy has become increasingly global. In economics, for example, policy has followed the so-called Washington Consensus of privatization, liberalization, and deregulation. In education, global policy has included the proliferation of strategies including standardized testing, paraprofessional teachers, user fees, and privatization. There are many problems with these neoliberal policies. Foremost among them, is the havoc they wreak on the lives of so many children and adults. Poverty, inequality, and myriad associated problems have reached new heights in this neoliberal era. Moreover, these policies have been adopted uncritically and alternative policies have been ignored, which leads to our focus here.

Efficient articulated trajectory reconstruction using dynamic programming and filters

This paper considers the problem of reconstructing the motion of a 3D articulated tree from 2D point correspondences subject to some temporal prior. Hitherto, smooth motion has been encouraged using a trajectory basis, yielding a hard combinatorial problem with time complexity growing exponentially in the number of frames. Branch and bound strategies have previously attempted to curb this complexity whilst maintaining global optimality. However, they provide no guarantee of being more efficient than exhaustive search. Inspired by recent work which reconstructs general trajectories using compact high-pass filters, we develop a dynamic programming approach which scales linearly in the number of frames, leveraging the intrinsically local nature of filter interactions. Extension to affine projection enables reconstruction without estimating cameras.