Grounded Theory: A guide for a new generation of researchers

Aim/Purpose Grounded Theory (GT) has grown and developed into several strands making its application all the more problematic, argumentative and remaining potentially as a research methodology to avoid when it comes to doctoral research, early-career research. Thus, the purpose of this paper is to revisit GT as a general approach and present an evolved and more considered step-by-step guide to conduct research using this methodology. A leadership development context is applied in this paper to examine how this methodology could work for a new generation of researchers, i.e., new to doctoral research or an early career researcher. Background Since its academic inception in the seminal text in 1967 (Glaser & Strauss, 1967), GT has emerged and developed to become a popular choice for researchers contemplating qualitative data approaches amongst a variety of subject backgrounds. However, the divergent development and criticized approaches within GT families can lead researchers to avoid such a research methodology. This can especially be the case within doctoral research or other early-career research. Indeed, a specific/explicit GT guideline or framework to assist doctoral students in conducting GT research does not currently exist. Methodology There is a general review of GT approaches followed by theoretical development of a framework and an applied doctoral example. Contribution The three evolved methods in GT research and the developed supporting author-designed three-phase research framework will contribute to two aspects. Firstly, the step-by-step guideline can reduce the sense of confusion within an area where criticisms and conflicting approaches exist. This will hopefully assist the next generation of GT researchers in conducting their research through detailed processes and applications. Secondly, there is arguably a need for more GT applications and evolvements to further enrich the body of knowledge that exists in this area and further support a diversity of subject research. Findings The authors outline numerous differences and similarities within divergent GT practices. By integrating Glaser’s four core principles and three evolved methods, the authors design a three-phase research framework that presents a transparent step-by-step guide. This framework attempts to mitigate criticisms within GT approaches whilst maintaining clarity, flexibility, depth, and rigour within a study. Recommendations for Practitioners Three GT evolvements (the two-step literature review method, two-step open-coding method, and two-step theory-constitute method) provides greater clarity within a rigorous author-designed three-phase research framework that demonstrates a transparent step-by-step guide. These techniques can encourage a new generation of GT researcher through confident and structured analytical techniques. Recommendation for Researchers We hope the presented framework and concise view of GT in action will inspire other doctoral students and new GT researchers to conduct GT research following an evolved GT framework. Impact on Society The debates and innovations around GT, like in this paper, are needed within a methodological society to keep the area contemporary and constantly evolving. Future Research The framework presented will need further testing beyond the parameters set out here. We hope future research can adopt the evolved GT techniques and procedures to enforce research quality overall and inspire further GT methodological developments

Self-consistent model of unipolar transport in organic semiconductor diodes: accounting for a realistic density-of-states distribution

A self-consistent, mean-field model of charge-carrier injection and unipolar transport in an organic semiconductor diode is developed utilizing the effective transport energy concept and taking into account a realistic density-of-states distribution as well as the presence of trap states in an organic material. The consequences resulting from the model are discussed exemplarily on the basis of an indium tin oxide/organic semiconductor/metallic conductor structure. A comparison of the theory to experimental data of a unipolar indium tin oxide/poly-3-hexyl-thiophene/Al device is presented.Comment: 6 pages, 2 figures; to be published in Journal of Applied Physic

Metal-Free Nitrogen-Doped Carbon Foam Electrocatalysts for the Oxygen Reduction Reaction in Acid Solution

Metal-free, nitrogen-doped carbon foam is utilized as a model non-precious electrocatalyst system to investigate the role of nitrogen in the oxygen reduction reaction (ORR) in the absence of iron contamination. This graphene-like foam displays relatively high activity for the ORR in acid, despite being proven free from transition-metal impurities. The onset potential is 0.85 VRHE, the mass activity is 2.8 A/g at 0.6 VRHE, and the current density is −4.0 mA/cm2. The maximum electron transfer number is calculated to be 3.6, revealing that a 4-electron pathway is possible in nitrogen-doped carbon, even in the absence of transition-metal coordination sites. The excellent electrochemical activity is attributed to the large surface area (700 m2/g), improved conductivity after graphitization, and the relatively high proportion of tertiary (graphite-like) nitrogen

Study of one class boundary method classifiers for application in a video-based fall detection system

In this paper, we introduce a video-based robust fall detection system for monitoring an elderly person in a smart room environment. Video features, namely the centroid and orientation of a voxel person, are extracted. The boundary method, which is an example one class classification technique, is then used to determine whether the incoming features lie in the ‘fall region’ of the feature space, and thereby effectively distinguishing a fall from other activities, such as walking, sitting, standing, crouching or lying. Four different types of boundary methods, k-center, k-th nearest neighbor, one class support vector machine and single class minimax probability machine are assessed on representative test datasets. The comparison is made on the following three aspects: 1). True positive rate, false positive rate and geometric means in detection 2). Robustness to noise in the training dataset 3). The computational time for the test phase. From the comparison results, we show that the single class minimax probability machine achieves the best overall performance. By applying one class classification techniques with 3-d features, we can obtain a more efficient fall detection system with acceptable performance, as shown in the experimental part; besides, it can avoid the drawbacks of other traditional fall detection methods

Using Markov Models and Statistics to Learn, Extract, Fuse, and Detect Patterns in Raw Data

Many systems are partially stochastic in nature. We have derived data driven approaches for extracting stochastic state machines (Markov models) directly from observed data. This chapter provides an overview of our approach with numerous practical applications. We have used this approach for inferring shipping patterns, exploiting computer system side-channel information, and detecting botnet activities. For contrast, we include a related data-driven statistical inferencing approach that detects and localizes radiation sources.Comment: Accepted by 2017 International Symposium on Sensor Networks, Systems and Securit

Radiative corrections to neutrino mass matrix in the Standard Model and beyond

We study the effect of radiative corrections on the structure of neutrino mass matrix. We analyze the renormalization of the matrix from the electroweak scale $m_Z$ to the scale $m_0$ at which the effective operator that gives masses to neutrinos is generated. Apart from Standard Model and MSSM, non-standard extensions of SM are considered at a scale $m_X$ intermediate between $m_Z$ and $m_0$. We find that the dominant structure of the neutrino mass matrix does not change. SM and MSSM corrections produce small (few percents) independent renormalization of each matrix element. Non-standard (flavor changing) corrections can modify strongly small (sub-dominant) matrix elements, which are important for the low energy phenomenology. In particular, we show that all sub-dominant elements can have purely radiative origin, being zero at $m_0$. The set of non-zero elements at $m_0$ can be formed by (i) diagonal elements (unit matrix); (ii) $M_{ee}$ and $M_{\mu\tau}$; (iii)$M_{ee}$ and $\mu\tau$-block elements; (iv) $\mu\tau$-block elements. In the case of unit matrix, both atmospheric and solar mixing angles and mass squared differences are generated radiatively.Comment: 22 pages, 5 eps figures, JHEP3.cls, some clarifications and one reference adde

Targeting lentiviral vectors to antigen-specific immunoglobulins

Gene transfer into B cells by lentivectors can provide an alternative approach to managing B lymphocyte malignancies and autoreactive B cell-mediated autoimmune diseases. These pathogenic B cell Populations can be distinguished by their surface expression of monospecific immunoglobulin. Development of a novel vector system to deliver genes to these specific B cells could improve the safety and efficacy of gene therapy. We have developed an efficient rnethod to target lentivectors to monospecific immunoglobulin-expressing cells in vitro and hi vivo. We were able to incorporate a model antigen CD20 and a fusogenic protein derived from the Sindbis virus as two distinct molecules into the lentiviral Surface. This engineered vector could specifically bind to cells expressing Surface immunoglobulin recognizing CD20 (αCD20), resulting in efficient transduction of target cells in a cognate antigen-dependent manner in vitro, and in vivo in a xenografted tumor model. Tumor suppression was observed in vivo, using the engineered lentivector to deliver a suicide gene to a xenografted tumor expressing αCD20. These results show the feasibility of engineering lentivectors to target immunoglobulin-specific cells to deliver a therapeutic effect. Such targeting lentivectors also Could potentially be used to genetically mark antigen-specific B cells in vivo to study their B cell biology

Data Locality Aware Strategy for Two-Phase Collective I/O

Abstract. This paper presents Locality-Aware Two-Phase (LATP) I/O, an opti-mization of the Two-Phase collective I/O technique from ROMIO, the most pop-ular MPI-IO implementation. In order to increase the locality of the file accesses, LATP employs the Linear Assignment Problem (LAP) for finding an optimal dis-tribution of data to processes, an aspect that is not considered in the original tech-nique. This assignment is based on the local data that each process stores and has as main purpose the reduction of the number of communication involved in the I/O collective operation and, therefore, the improvement of the global execution time. Compared with Two-Phase I/O, LATP I/O obtains important improvements in most of the considered scenarios.

Equations for filling factor estimation in opal matrix

We consider two equations for the filling factor estimation of infiltrated zinc oxide (ZnO) in silica (SiO_2) opal and gallium nitride in ZnO opal. The first equation is based on the effective medium approximation, while the second one - on Maxwell-Garnett approximation. The comparison between two filling factors shows that both equations can be equally used for the estimation of the quantity of infiltrated nanocrystals inside opal matrix.Comment: 14 pages, 7 figures, 1 table. Addendum to the article: http://arxiv.org/abs/physics/050815

Splitting of Landau levels of a 2D electron due to electron-phonon interactions

We show that in a very strong magnetic field $B$ electron-phonon interaction gives rise to a splitting of Landau levels of a 2D electron into a series of infinitely degenerate sublevels. We provide both qualitative and quantitative description of this phenomenon. The cases of interaction with acoustic and polar optical phonons are considered. The energy distance between nearest sublevels in both cases tends to zero as $B^{-1/2}$ at large $B$.Comment: 4 pages, LaTe