A Gray Code for the Shelling Types of the Boundary of a Hypercube

We consider two shellings of the boundary of the hypercube equivalent if one can be transformed into the other by an isometry of the cube. We observe that a class of indecomposable permutations, bijectively equivalent to standard double occurrence words, may be used to encode one representative from each equivalence class of the shellings of the boundary of the hypercube. These permutations thus encode the shelling types of the boundary of the hypercube. We construct an adjacent transposition Gray code for this class of permutations. Our result is a signed variant of King's result showing that there is a transposition Gray code for indecomposable permutations

Quasi-specular reflection from particulate media

Specular reflection is known to play an important role in many fields of scattering applications, e.g., in remote sensing, computer graphics, optimization of visual appearance of industrial products. Usually it can be assumed that the object has a solid surface and that the properties of the surface will dictate the behavior of the specular component. In this study I will show that media consisting of wavelength-sized particles can also have a quasi-specular reflection in cases where there is ordered structure in the media. I will also show that the quasi-specular reflection in particulate media is more than just a surface effect, and planar particle arrangement below the very surface can give arise to quasi-specular reflection. This study shows that the quasi-specular reflection may contribute in some cases in the backscattering direction, together with coherent backscattering and shadow-hiding effects

Postmortem iris recognition and its application in human identification

Iris recognition is a validated and non-invasive human identification technology currently implemented for the purposes of surveillance and security (i.e. border control, schools, military). Similar to deoxyribonucleic acid (DNA), irises are a highly individualizing component of the human body. Based on a lack of genetic penetrance, irises are unique between an individual’s left and right iris and between identical twins, proving to be more individualizing than DNA. At this time, little to no research has been conducted on the use of postmortem iris scanning as a biometric measurement of identification. The purpose of this pilot study is to explore the use of iris recognition as a tool for postmortem identification. Objectives of the study include determining whether current iris recognition technology can locate and detect iris codes in postmortem globes, and if iris scans collected at different postmortem time intervals can be identified as the same iris initially enrolled. Data from 43 decedents involving 148 subsequent iris scans demonstrated a subsequent match rate of approximately 80%, supporting the theory that iris recognition technology is capable of detecting and identifying an individual’s iris code in a postmortem setting. A chi-square test of independence showed no significant difference between match outcomes and the globe scanned (left vs. right), and gender had no bearing on the match outcome. There was a significant relationship between iris color and match outcome, with blue/gray eyes yielding a lower match rate (59%) compared to brown (82%) or green/hazel eyes (88%), however, the sample size of blue/gray eyes in this study was not large enough to draw a meaningful conclusion. An isolated case involving an antemortem initial scan collected from an individual on life support yielded an accurate identification (match) with a subsequent scan captured at approximately 10 hours postmortem. Falsely rejected subsequent iris scans or "no match" results occurred in about 20% of scans; they were observed at each PMI range and varied from 19-30%. The false reject rate is too high to reliably establish non-identity when used alone and ideally would be significantly lower prior to implementation in a forensic setting; however, a "no match" could be confirmed using another method. Importantly, the data showed a false match rate or false accept rate (FAR) of zero, a result consistent with previous iris recognition studies in living individuals. The preliminary results of this pilot study demonstrate a plausible role for iris recognition in postmortem human identification. Implementation of a universal iris recognition database would benefit the medicolegal death investigation and forensic pathology communities, and has potential applications to other situations such as missing persons and human trafficking cases

General BER Expression for One-Dimensional Constellations

A novel general ready-to-use bit-error rate (BER) expression for one-dimensional constellations is developed. The BER analysis is performed for bit patterns that form a labeling. The number of patterns for equally spaced M-PAM constellations with different BER is analyzed.Comment: To appear in the Proceedings of the IEEE Global Communications Conference (GLOBECOM) 2012. Remark 3 modifie

Reflexive Learning and Performative Failure

In this paper we emphasize the importance of context for student learning. Based on reflective logs and interview data, we explore how students learn outside of the classroom as they undertake an experiential dissertation project. We identify three different forms of reflexive learning and critique, all triggered by some form of performative failure; scholarly critique, engaged critique and engaged action. Drawing on Butler’s theory of performativity we illustrate how reflexivity is not purely the action of any individual student, rather it is a practice that is co-created within a certain context. As such, we contest individualistic understandings of reflexivity and encourage a careful consideration of the places students and managers are encouraged to be reflexive

Asymptotically Optimal Quantum Circuits for d-level Systems

As a qubit is a two-level quantum system whose state space is spanned by |0>, |1>, so a qudit is a d-level quantum system whose state space is spanned by |0>,...,|d-1>. Quantum computation has stimulated much recent interest in algorithms factoring unitary evolutions of an n-qubit state space into component two-particle unitary evolutions. In the absence of symmetry, Shende, Markov and Bullock use Sard's theorem to prove that at least C 4^n two-qubit unitary evolutions are required, while Vartiainen, Moettoenen, and Salomaa (VMS) use the QR matrix factorization and Gray codes in an optimal order construction involving two-particle evolutions. In this work, we note that Sard's theorem demands C d^{2n} two-qudit unitary evolutions to construct a generic (symmetry-less) n-qudit evolution. However, the VMS result applied to virtual-qubits only recovers optimal order in the case that d is a power of two. We further construct a QR decomposition for d-multi-level quantum logics, proving a sharp asymptotic of Theta(d^{2n}) two-qudit gates and thus closing the complexity question for all d-level systems (d finite.) Gray codes are not required, and the optimal Theta(d^{2n}) asymptotic also applies to gate libraries where two-qudit interactions are restricted by a choice of certain architectures.Comment: 18 pages, 5 figures (very detailed.) MatLab files for factoring qudit unitary into gates in MATLAB directory of source arxiv format. v2: minor change

Art and the Human Condition: Incorporating Visual Analysis of Artworks into a Undergraduate Pre-Medicine Curriculum

This thesis project presents a sample class session for the course, The Human Condition: An Arts Perpective (ARTH 361), which will be a part of the optional Medical Humanities minor for the pre-medicine students at Virginia Commonwealth University (VCU). Dr. Margaret Lindauer, Associate Professor of Art History at VCU has directed the development of this course. She oversaw the creation of the preliminary syllabus, which includes readings and assignments relevant to the course. The Tour presented in this thesis project provides a model for planning other class sessions, some of which will be developed by Museum Studies graduate students, some of whom might not have previous experience facilitating gallery tours. I assert that tours such as the one proposed in this project provide pre-medicine students with the opportunity to practice observational skills outside of the clinical setting. In looking at art, pre-medicine students approach the act of observation from a different angle and discussion about art objects often have valuable insight about the medical profession they are entering into. This thesis report accordingly offers brief summaries of research studies that were consulted while the aforementioned tour was developed. It also includes the author\u27s experiences working with a group of pre-nursing undergraduate student at VCU, and it includes a summary of the devloped tour as well as feedback provided by a VMFA Education Department staff member

Corporate Social Responsibility in Supply Chains of Global Brands: A Boundaryless Responsibility? Clarifications, exceptions and implications

Corporate social responsibility (CSR) is increasingly becoming a popular business concept in developed economies. As typical of other business concepts, it is on its way to globalization through practices and structures of the globalized capitalist world order, typified in Multinational Corporations (MNCs). However, CSR often sits uncomfortably in this capitalist world order, as MNCs are often challenged by the global reach of their supply chains and the possible irresponsible practices inherent along these chains. The possibility of irresponsible practices puts global firms under pressure to protect their brands even if it means assuming responsibilities for the practices of their suppliers. Pressure groups understand this burden on firms and try to take advantage of the situation. This paper seeks to challenge the often taken-for-granted-assumption that firms should be accountable for the practices of their suppliers by espousing the moral (and sometimes legal) underpinnings of the concept of responsibility. Except where corporate control and or corporate grouping exist, it identifies the use of power as a critical factor to be considered in allocating responsibility in firm-supplier relationship; and suggests that the more powerful in this relationship has a responsibility to exert some moral influence on the weaker party. The paper highlights the use of code of conducts, corporate culture, anti-pressure group campaigns, personnel training and value reorientation as possible sources of wielding positive moral influence along supply chains

Using shared online blogs to structure and support informal coach learning. Part 2: The participants’ view and implications for coach education

In part one of this paper, Stoszkowski and Collins (2015) showed that shared online blogs were a useful tool to structure and support the informal learning of a cohort of final year undergraduate sports coaching students. The aim of the present study was to offer insight into student coaches’ perceptions of their use and experiences of structured group blogging for reflection and learning. Twenty-three student coaches (5 females, 18 males), purposely sampled from the original study, took part in four semi-structured focus group interviews. Interview data were inductively analysed. Student coaches were generally very positive about their learning experiences and the pedagogical approach employed. This was especially apparent in terms of perceived increases in levels of reflection, knowledge acquisition and improvements in coaching practice; changes corroborated by the data presented in part one. A range of reasons emerged for these outcomes, alongside several potential limiters of engagement in shared group blogging as a learning endeavour. Whilst these findings support recent, and growing proposals to systematically incorporate Web 2.0 technologies such as blogs into coach education pedagogy, several key considerations for the process of using such tools are outlined. Finally, the implications for coach educators are discussed