Failure of intuition in elementary rigid body dynamics

Suppose a projectile collides perpendicularly with a stationary rigid rod on a smooth horizontal table. We show that, contrary to what one naturally expects, it is not always the case that the rod acquires maximum angular velocity when struck at an extremity. The treatment is intended for first year university students of Physics or Engineering, and could form the basis of a tutorial discussion of conservation laws in rigid body dynamics.Comment: Four pages; to appear in European Journal of Physic

Marketing in SMEs: a '4Ps' self-branding model

Purpose – The purpose of this paper is to explore the extent to which traditional marketing theory and practice can be applied in small- and medium-sized enterprises (SMEs) and consider how owner-managers perceive their own role in marketing within a small business setting. Design/methodology/approach – A qualitative exploratory approach using semi-structured in-depth interviews amongst owner-managers of SMEs in the UK. Findings – SME marketing is effective in that it embraces some relevant concepts of traditional marketing, tailors activities to match its customers and adds its own unique attribute of self-branding as bestowed by the SME owner-manager. Research limitations/implications – The study was limited to the UK and to a small sample of SMEs and as such the findings are not necessarily generalisable. Originality/value – A “4Ps” model for SME self-branding is proposed, which encompasses the attributes of personal branding, (co)production, perseverance and practice

Learning Design: reflections on a snapshot of the current landscape

The mounting wealth of open and readily available information and the swift evolution of social, mobile and creative technologies warrant a re-conceptualisation of the role of educators: from providers of knowledge to designers of learning. This need is being addressed by a growing trend of research in Learning Design. Responding to this trend, the Art and Science of Learning Design workshop brought together leading voices in the field and provided a forum for discussing its key issues. It focused on three thematic axes: practices and methods, tools and resources, and theoretical frameworks. This paper reviews some definitions of Learning Design and then summarises the main contributions to the workshop. Drawing upon these, we identify three key challenges for Learning Design that suggest directions for future research

Path integrals and wavepacket evolution for damped mechanical systems

Damped mechanical systems with various forms of damping are quantized using the path integral formalism. In particular, we obtain the path integral kernel for the linearly damped harmonic oscillator and a particle in a uniform gravitational field with linearly or quadratically damped motion. In each case, we study the evolution of Gaussian wavepackets and discuss the characteristic features that help us distinguish between different types of damping. For quadratic damping, we show that the action and equation of motion of such a system has a connection with the zero dimensional version of a currently popular scalar field theory. Furthermore we demonstrate that the equation of motion (for quadratic damping) can be identified as a geodesic equation in a fictitious two-dimensional space.Comment: 15 pages, 6 figure

Method and Apparatus for Controlling Acoustic Signal Bandwidth in an Ultrasonic Diagnostic Imaging System

An ultrasonic imaging system includes a receive beam former that generates analog receive signals and a scan converter. A receive signal processing path interconnects the receive beamformer and the scan converter, and this processing path includes both an A/D converter characterized by a selectable sampling rate and at least one filter characterized by at least one filter parameter. The filter parameter is selected as a function of the sampling rate to provide enhanced image quality

Yearly update : exascale projections for 2013.

The HPC architectures of today are significantly different for a decade ago, with high odds that further changes will occur on the road to Exascale. This paper discusses the %E2%80%9Cperfect storm%E2%80%9D in technology that produced this change, the classes of architectures we are dealing with, and probable trends in how they will evolve. These properties and trends are then evaluated in terms of what it likely means to future Exascale systems and applications.

Utilization of CT scanning associated with complex spine surgery.

BackgroundDue to the risk associated with exposure to ionizing radiation, there is an urgent need to identify areas of CT scanning overutilization. While increased use of diagnostic spinal imaging has been documented, no previous research has estimated the magnitude of follow-up imaging used to evaluate the postoperative spine.MethodsThis retrospective cohort study quantifies the association between spinal surgery and CT utilization. An insurance database (Humana, Inc.) with ≈ 19 million enrollees was employed, representing 8 consecutive years (2007-2014). Surgical and imaging procedures were captured by anatomic-specific CPT codes. Complex surgeries included all cervical, thoracic and lumbar instrumented spine fusions. Simple surgeries included discectomy and laminectomy. Imaging was restricted to CT and MRI. Postoperative imaging frequency extended to 5-years post-surgery.ResultsThere were 140,660 complex spinal procedures and 39,943 discectomies and 49,889 laminectomies. MRI was the predominate preoperative imaging modality for all surgical procedures (median: 80%; range: 73-82%). Postoperatively, CT prevalence following complex procedures increased more than two-fold from 6 months (18%) to 5 years (≥40%), and patients having a postoperative CT averaged two scans. For simple procedures, the prevalence of postoperative CT scanning never exceeded 30%.ConclusionsCT scanning is used frequently for follow-up imaging evaluation following complex spine surgery. There is emerging evidence of an increased cancer risk due to ionizing radiation exposure with CT. In the setting of complex spine surgery, actions to mitigate this risk should be considered and include reducing nonessential scans, using the lowest possible radiation dose protocols, exerting greater selectivity in monitoring the developing fusion construct, and adopting non-ferromagnetic implant biomaterials that facilitate MRI postoperatively

RAFCON: a Graphical Tool for Task Programming and Mission Control

There are many application fields for robotic systems including service robotics, search and rescue missions, industry and space robotics. As the scenarios in these areas grow more and more complex, there is a high demand for powerful tools to efficiently program heterogeneous robotic systems. Therefore, we created RAFCON, a graphical tool to develop robotic tasks and to be used for mission control by remotely monitoring the execution of the tasks. To define the tasks, we use state machines which support hierarchies and concurrency. Together with a library concept, even complex scenarios can be handled gracefully. RAFCON supports sophisticated debugging functionality and tightly integrates error handling and recovery mechanisms. A GUI with a powerful state machine editor makes intuitive, visual programming and fast prototyping possible. We demonstrated the capabilities of our tool in the SpaceBotCamp national robotic competition, in which our mobile robot solved all exploration and assembly challenges fully autonomously. It is therefore also a promising tool for various RoboCup leagues.Comment: 8 pages, 5 figure

Moments of inertia for solids of revolution and variational methods

We present some formulae for the moments of inertia of homogeneous solids of revolution in terms of the functions that generate the solids. The development of these expressions exploits the cylindrical symmetry of these objects, and avoids the explicit use of multiple integration, providing an easy and pedagogical approach. The explicit use of the functions that generate the solid gives the possibility of writing the moment of inertia as a functional, which in turn allows us to utilize the calculus of variations to obtain a new insight into some properties of this fundamental quantity. In particular, minimization of moments of inertia under certain restrictions is possible by using variational methods.Comment: 6 pages, 6 figures, LaTeX2e. Two paragraphs added. Minor typos corrected. Version to appear in European Journal of Physic

Educating graduates for marketing in SMEs: an update for the traditional marketing curriculum

Purpose – Despite rising graduate unemployment in the UK, there are insufficient numbers of graduates employed in small and medium sized enterprises (SMEs). The literature suggests that a teaching emphasis on large organisational business models in Higher Education Institutions (HEI), particularly in the teaching of marketing theory, renders the SME sector unattractive to graduate employment and conversely, it is perceived that graduates lack additional ‘soft skills’ vital for SME development and growth. The aim of this study is to provide an analysis of how SMEs define marketing and to compare student perspective on marketing within a SME context. This paper also examines the need to improve the conventional marketing curriculum with additional teaching solutions that consider the reality of UK SME ownership and student employment prospects. Design/methodology/approach – A qualitative research approach was adopted using in-depth interviews amongst ten SME owners and twenty undergraduate marketing students of a UK University. Findings – Findings revealed that the marketing practices used in SMEs were not present in the marketing curriculum in the case University. The employment of marketing graduates was not positively perceived by SME owners and equally, marketing undergraduates did not view SMEs as the career organisation of choice. Research limitations/implications – The findings suggest that Universities need to adapt their marketing curriculum to inform students of the realities of SME marketing practice and better prepare them for future employment in this sector, which contributes significantly to the overall economy and job creation in the UK. Originality/value – Our study re-evaluates the HE marketing curriculum and suggests an update of the curriculum in order to move the university-industry-government relationship away from the traditional knowledge transfer perspective