Anomaly detection is an important problem that has been researched within diverse research areas and application domains. Many anomaly detection techniques have been specifically developed for certain application domains, while others are more generic. This survey tries to provide a structured and comprehensive overview of the research on anomaly detection. We have grouped existing techniques into different categories based on the underlying approach adopted by each technique. For each category we have identified key assumptions, which are used by the techniques to differentiate between normal and anomalous behavior. When applying a given technique to a particular domain, these assumptions can be used as guidelines to assess the effectiveness of the technique in that domain. For each category, we provide a basic anomaly detection technique, and then show how the different existing techniques in that category are variants of the basic technique. This template provides an easier and more succinct understanding of the techniques belonging to each category. Further, for each category, we identify the advantages and disadvantages of the techniques in that category. We also provide a discussion on the computational complexity of the techniques since it is an important issue in real application domains. We hope that this survey will provide a better understanding of the different directions in which research has been done on this topic, and how techniques developed in one area can be applied in domains for which they were not intended to begin with.

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Anomaly detection: A survey

A review of shape memory alloy research, applications and opportunities

Numerical Initial Value Problems in Ordinary Differential Equations

Novelty detection: a review—part 1: statistical approaches

With the increasing advances in hardware technology for data collection, and advances in software technology (databases) for data organization, computer scientists have increasingly participated in the latest advancements of the outlier analysis field. Computer scientists, specifically, approach this field based on their practical experiences in managing large amounts of data, and with far fewer assumptions the data can be of any type, structured or unstructured, and may be extremely large. Outlier Analysisis a comprehensive exposition, as understood by data mining experts, statisticians and computer scientists. The book has been organized carefully, and emphasis was placed on simplifying the content, so that students and practitioners can also benefit. Chapters will typically cover one of three areas: methods and techniques commonly used in outlier analysis, such as linear methods, proximity-based methods, subspace methods, and supervised methods; data domains, such as, text, categorical, mixed-attribute, time-series, streaming, discrete sequence, spatial and network data; and key applications of these methods as applied to diverse domains such as credit card fraud detection, intrusion detection, medical diagnosis, earth science, web log analytics, and social network analysis are covered.

Outlier Analysis

A novel approach involving the use of the force appro priation testing for flight flutter testing using PZT patches is described. It is shown how the traditional flight flutter test procedure can be improved through the use of multi -excitation force appropriation resulting in superior estimates of frequenci es, damping ratios and mode shapes. This improved identification procedure enables better estimates of critical flutter boundaries to be achieved compared to traditional phase separation methods. The approach is demonstrated upon simulated rectangular an d swept wings. A procedure for determining the optimal positioning of the PZT patches is also described.

Force appropriation for flight flutter testing using smart devices

Prediction of maximum loads due to turbulent gusts using nonlinear system identification

This paper numerically and experimentally investigates the relationship between the nonlinear normal modes and the forced response of a clamped-clamped cross beam structure. The system possesses closely-spaced linear modes such that the applied force distribution across the structure plays a central role in the appropriation of the nonlinear normal modes. Numerical simulations show that the quadrature conditions of the forced response does not necessarily match the peak response nor the nonlinear normal modes of the underlying conservative system, but instead are dependent upon the applied excitation. Experimental investigations performed with a single-point excitation and control based continuation further demonstrate the necessity for appropriate forcing in order to extract the NNMs of such systems.

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Connecting nonlinear normal modes to the forced response of a geometric nonlinear structure with closely spaced modes

Aeroelastic performance controls wing shape in flight and its behaviour under manoeuvre and gust loads. Controlling the wing’s aeroelastic performance can therefore offer weight and fuel savings. In this paper, the rib orientation and the crenellated skin concept are used to control wing deformation under aerodynamic load. The impact of varying the rib/crenellation orientation, the crenellation width and thickness on the tip twist, tip displacement, natural frequencies, flutter speed and gust response are investigated. Various wind-off and wind-on loads are considered through Finite Element modelling and experiments, using wings manufactured through polyamide laser sintering. It is shown that it is possible to influence the aeroelastic behaviour using the rib and crenellation orientation, e.g. flutter speed increased by up to 14.2% and gust loads alleviated by up to 6.4%. A reasonable comparison between numerical and experimental results was found.

Aeroelastic tailoring using crenelated skins - Modelling and experiment

/pdf/optimization-of-aerospace-structures-under-uncertainty-using-2wup38uhsu.pdf

Jonathan E. Cooper

Papers

Force appropriation for flight flutter testing using smart devices

Prediction of maximum loads due to turbulent gusts using nonlinear system identification

Connecting nonlinear normal modes to the forced response of a geometric nonlinear structure with closely spaced modes

Aeroelastic tailoring using crenelated skins - Modelling and experiment

Optimization of Aerospace Structures Under Uncertainty Using an Iterative Distribution Evolutionary Algorithm