In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Forecasting, Structural Time Series Models and the Kalman Filter

An overview of the self-organizing map algorithm, on which the papers in this issue are based, is presented in this article.

The Self-Organizing Map

One of the most important design problems for multi-UAV (Unmanned Air Vehicle) systems is the communication which is crucial for cooperation and collaboration between the UAVs. If all UAVs are directly connected to an infrastructure, such as a ground base or a satellite, the communication between UAVs can be realized through the in-frastructure. However, this infrastructure based communication architecture restricts the capabilities of the multi-UAV systems. Ad-hoc networking between UAVs can solve the problems arising from a fully infrastructure based UAV networks. In this paper, Flying Ad-Hoc Networks (FANETs) are surveyed which is an ad hoc network connecting the UAVs. The differences between FANETs, MANETs (Mobile Ad-hoc Networks) and VANETs (Vehicle Ad-Hoc Networks) are clarified first, and then the main FANET design challenges are introduced. Along with the existing FANET protocols, open research issues are also discussed.

Flying Ad-Hoc Networks (FANETs)

A number of contributed solutions to the problem of laminar natural convection in a square cavity have been compared with what is regarded as a solution of high accuracy. The purposes of this exercise have been to confirm the accuracy of the bench mark solution and to provide a basis for the assessment of the various methods and computer codes used to obtain the contributed solutions.

Natural convection in a square cavity: A comparison exercise

Laminar and turbulent natural convection in an enclosed cavity

The Phillips Curve in Australia

A theoretical model for ice growth due to droplets of supercooled fluid impacting on a subzero substrate is presented. In cold conditions rime (dry) ice forms and the problem reduces to solving a simple mass balance. In milder conditions glaze (wet) ice forms. The problem is then governed by coupled mass and energy balances, which determine the ice height and water layer thickness. The model is valid for “thin” water layers, such that lubrication theory may be applied and the Peclet number is small; it is applicable to ice accretion on stationary and moving structures. A number of analytical solutions are presented. Two- and three-dimensional numerical schemes are also presented, to solve the water flow equation, these employ a flux-limiting scheme to accurately model the capillary ridge at the leading edge of the flow. The method is then extended to incorporate ice accretion. Numerical results are presented for ice growth and water flow driven by gravity, surface tension, and a constant air shear.

Slowly accreting ice due to supercooled water impacting on a cold surface

This paper presents a small model of the Australian macroeconomy. The model is empirically based, aggregate in nature and consists of five estimated equations – for non-farm output, the real exchange rate, import prices, unit labour costs and consumer prices. The stylised facts underlying each equation are discussed and estimation results are presented. The model’s primary use is to examine macroeconomic developments over the short to medium term, although it also has a well-defined steady state in the longer run with appropriate theoretical properties. Dynamic responses of the model to monetary policy changes and selected shocks are illustrated in the paper.

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A Small Model of the Australian Macroeconomy

In this paper we discuss the development of Phillips curves in Australia over the forty years since Phillips first estimated one using Australian data. We examine the central issues faced by researchers estimating Australian Phillips curves. These include the distinction between the short and long-run trade-offs between inflation and unemployment, and the changing level of the non-accelerating inflation rate of unemployment (NAIRU), particularly in the 1970s. We estimate Phillips curves for prices and unit labour costs in Australia over the past three decades. These Phillips curves allow the NAIRU to change through time, and include a role for import prices and ‘speed-limit’ effects. The paper concludes by presenting an extended discussion of the changing role of the Phillips curve in the intellectual framework used to analyse inflation within the Reserve Bank of Australia over the past three decades.

Obstacle detection and classification in a complex urban area are highly demanding, but desirable for pedestrian protection, stop & go, and enhanced parking aids. The most difficult task for the system is to segment objects from varied and complicated background. In this paper, a novel position-based object segmentation method has been proposed to solve this problem. According to the method proposed, object segmentation is performed in two steps: in depth map (X-Z plane) and in layered images (X-Y planes). The stereovision technique is used to reconstruct image points and generate the depth map. Objects are detected in the depth map. Afterwards, the original edge image is separated into different layers based on the distance of detected objects. Segmentation performed in these layered images can be easier and more reliable. It has been proved that the proposed method offers robust detection of potential obstacles and accurate measurement of their location and size.

/pdf/stereovision-based-object-segmentation-for-automotive-9k6k1g7hj9.pdf

Christopher Thompson

Papers

The Phillips Curve in Australia

Slowly accreting ice due to supercooled water impacting on a cold surface

A Small Model of the Australian Macroeconomy

The Phillips Curve in Australia

Stereovision-based object segmentation for automotive applications