Netnography: A Method Specifically Designed to Study Cultures and Communities Online

With many people now using online communities such as newsgroups, blogs, forums, social networking sites, podcasting, videocasting, photosharing communities, and virtual worlds, the internet is now an important site for research. Kozinets\u27 (2010) new text explores netnography, or the conduct of ethnography over the internet - a method specifically designed to study cultures and communities online. Guidelines for the accurate and ethical conduct of ethnographic research online are set out, with detailed, step-by-step guidance to thoroughly introduce, explain, and illustrate the method to students and researchers. Kozinets surveys the latest research on online cultures and communities, focusing on the methods used to study them, with examples focusing on the blogosphere (blogging), microblogging, videocasting, podcasting, social networking sites, virtual worlds, and more. The book is essential reading for researchers and students in social sciences

Forty Years in the Making: Harry Wolcott Shares his Expertise in Writing Up Qualitative Research

Harry Wolcott’s major focus in the third edition of Writing Up Qualitative Research is on writing what has come to be known as qualitative or descriptive or naturalistic research. To this end Wolcott draws upon the experiences from his life in the field of qualitative inquiry from over the past 40 years to offer suggestions on every aspect of the writing process from the beginning to end of a qualitative research project. Wolcott discusses how to jump start the writing process by providing guidance ranging from when and how to begin, how to keep the writing process going, what to do by way of tightening up a manuscript, and how to prepare an article or book for publication

Benchmark Problems in Eddy-Current NDE

Inversion of eddy-current data and the reconstruction of flaws is the preeminent problem in electromagnetic nondestructive evaluation (NDE). This places a premium on developing good forward models for computing field-flaw interactions, because all inversion algorithms must, of necessity, rely on such calculations. There has evolved in recent years several sophisticated computational models for the forward problem [1–4], but these models differ significantly in their theoretical and numerical approaches. For example, [1-3] use a volume-integral approach that incorporates fast Fourier transforms with conjugate gradients to solve the resulting linear system of equations, whereas [4] uses finite-elements

Pulsed Eddy-Current Measurements for the Characterization of Thin Layers and Surface Treatments

By using a transient excitation, eddy-current probes exhibit a diffuse pulse-echo response in the presence of stratified conductors. The response has been investigated in order to evaluate pulsed eddy-current signals due to a single conducting layer over a uniform substrate of dissimilar conductivity. The aim of the investigation is to assess the feasibility of measuring the thickness and quality of surface treatments including the diffusion of aluminum into nickel parts and the case hardening of steel components

Low Frequency, Pulsed Eddy Currents for Deep Penetration

Using eddy-currents to detect flaws buried deeply in a conducting material has always been a difficult problem. This is due in part to the fact that deep penetration requires low frequencies so that the skin depth is large enough for the eddy-currents to penetrate into the material the depth of the flaw. Also, low frequency eddy-current methods are beset with difficulties in probe design. In order to achieve the large inductance needed to operate at frequencies below 1 kHz, a large number of turns is needed, adding to the resistance of the coil and reducing the energy available to couple into the test piece. One solution is to use pulsed eddy-current methods, which operate efficiently and effectively with low inductance coils.</p

Eddy Current Corner Crack Inspection

The purpose of this paper is to report on the development of an eddy current (EC) measurement model applicable to corner crack inspections. Naturally, corner cracks are more difficult to detect than those on flat surfaces, because the specimen edge itself gives a large response to the EC probe. The flaw signal, if any, tends to be obscured by the large edge signal. Thus, probe impedance should be determined more accurately than usual in order to extract flaw signals out of the background. Experimentally, this requires high-accuracy impedance measurements with rigid control over probe motion. In modeling point of view, this means that predictions should be made from an exact model, or at least from a model which can achieve the required level of accuracy [1–3]

Delayed self-recognition in children with autism spectrum disorder.

This study aimed to investigate temporally extended self-awareness (awareness of one’s place in and continued existence through time) in autism spectrum disorder (ASD), using the delayed self-recognition (DSR) paradigm (Povinelli et al., Child Development 67:1540–1554, 1996). Relative to age and verbal ability matched comparison children, children with ASD showed unattenuated performance on the DSR task, despite showing significant impairments in theory-of-mind task performance, and a reduced propensity to use personal pronouns to refer to themselves. The results may indicate intact temporally extended self-awareness in ASD. However, it may be that the DSR task is not an unambiguous measure of temporally extended self-awareness and it can be passed through strategies which do not require the possession of a temporally extended self-concept

Equivalence between free quantum particles and those in harmonic potentials and its application to instantaneous changes

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedIn quantum physics the free particle and the harmonically trapped particle are arguably the most important systems a physicist needs to know about. It is little known that, mathematically, they are one and the same. This knowledge helps us to understand either from the viewpoint of the other. Here we show that all general time-dependent solutions of the free-particle Schrodinger equation can be mapped to solutions of the Schrodinger equation for harmonic potentials, both the trapping oscillator and the inverted `oscillator'. This map is fully invertible and therefore induces an isomorphism between both types of system, they are equivalent. A composition of the map and its inverse allows us to map from one harmonic oscillator to another with a different spring constant and different center position. The map is independent of the state of the system, consisting only of a coordinate transformation and multiplication by a form factor, and can be chosen such that the state is identical in both systems at one point in time. This transition point in time can be chosen freely, the wave function of the particle evolving in time in one system before the transition point can therefore be linked up smoothly with the wave function for the other system and its future evolution after the transition point. Such a cut-and-paste procedure allows us to describe the instantaneous changes of the environment a particle finds itself in. Transitions from free to trapped systems, between harmonic traps of different spring constants or center positions, or, from harmonic binding to repulsive harmonic potentials are straightforwardly modelled. This includes some time dependent harmonic potentials. The mappings introduced here are computationally more efficient than either state-projection or harmonic oscillator propagator techniques conventionally employed when describing instantaneous (non-adiabatic) changes of a quantum particle's environmentPeer reviewe

Eddy-Current Detection Methods for Surface-Breaking Tight Cracks

The eddy-current (EC) NDE method has been in use for quite some time, and efforts have been made to make it a fully quantitative method. To evaluate impedance signals for a given EC inspection system, one has to characterize the system as a whole, including both probes and specimens. In particular, until probes are characterized, the electromagnetic fields cannot be calculated. Naturally, the amount of numerical computation becomes a serious issue during the course of development. It is necessary to choose probes carefully so as to maximize the flaw-characterization capability, while keeping numerical tasks within a reasonable size. Probes that are suitable for quantitative assessment are presumably different in nature from those with maximum detection capability. Among all kinds of existing probes, the simplest characterizable probe is the uniform-field-eddy-current (UFEC) probe. In fact, a series of studies, both theoretical and experimental, were devoted to demonstrating potential capabilities of UFEC probes [1–9]. The present theoretical work is another entry in this series. The numerical procedure developed in this work is limited to the case where cracks are tightly closed. The procedure is nevertheless capable, in principle, of dealing with an arbitrary range of frequencies