A Project Based Approach to Statistics and Data Science

In an increasingly data-driven world, facility with statistics is more important than ever for our students. At institutions without a statistician, it often falls to the mathematics faculty to teach statistics courses. This paper presents a model that a mathematician asked to teach statistics can follow. This model entails connecting with faculty from numerous departments on campus to develop a list of topics, building a repository of real-world datasets from these faculty, and creating projects where students interface with these datasets to write lab reports aimed at consumers of statistics in other disciplines. The end result is students who are well prepared for interdisciplinary research, who are accustomed to coping with the idiosyncrasies of real data, and who have sharpened their technical writing and speaking skills

The energy benefits of the pantograph wing mechanism in flapping flight:Case study of a gull

Bird wings generally contain a 4-bar pantograph mechanism in the forearm that enables the wrist joint to be actuated from the elbow joint thus reducing the number of wing muscles and hence reducing the wing inertia and inertial drag. In this paper we develop a theoretical model of inertial power for flapping flight to estimate the advantage of the 4-bar pantograph mechanism by comparing the inertial power required for the case where wrist muscles are present in the forearm with the case where wrist muscles are not present in the forearm. It is difficult to predict how wrist muscles would look when there is no pantograph mechanism. Therefore a lower bound and upper bound case are defined. The lower bound case involves redistributing the elbow muscles with no increase in wing mass. The upper bound case involves replicating the biceps-triceps muscles near the wrist joint. At minimum power speed the model estimates that the 4-bar pantograph mechanism reduces the inertial power for the gull from between 6.1%–12.3% and reduces the overall power by 0.6%–1.2%. When account is taken of the tight margins involved in the design of a flying vehicle, the energy savings produced by the pantograph mechanism are significant. A ring-billed gull was chosen for the case study and an adult specimen was obtained to gather morphometric data. Lessons for the design of flapping micro air vehicles are discussed. </jats:p

Cancellation of probe effects in measurements of spin polarized momentum density by electron positron annihilation

Measurements of the two dimensional angular correlation of the electron-positron annihilation radiation have been done in the past to detect the momentum spin density and the Fermi surface. We point out that the momentum spin density and the Fermi Surface of ferromagnetic metals can be revealed within great detail owing to the large cancellation of the electron-positron matrix elements which in paramagnetic multiatomic systems plague the interpretation of the experiments. We prove our conjecture by calculating the momentum spin density and the Fermi surface of the half metal CrO2, who has received large attention due to its possible applications as spintronics material

Communication in Hong Kong accident and emergency departments: The clinicians’ perspectives

© The Author(s) 2015. In this article, we report findings from the first qualitatively driven study of patient–clinician communication in Hong Kong Accident and Emergency Departments (AEDs). In light of the Hong Kong Hospital Authority’s policy emphasis on patientcentered care and communication in the public hospitals it oversees, we analyze clinicians’ perceptions of the role and relevance of patient-centered communication strategies in emergency care. Although aware of the importance of effective communication in emergency care, participants discussed how this was frequently jeopardized by chronic understaffing, patient loads, and time pressures. This was raised in relation to the absence of spoken interdisciplinary handovers, the tendency to downgrade interpersonal communication with patients, and the decline in staff attendance at communication training courses. Participants’ frequent descriptions of patient-centered communication as dispensable from, and timeburdensome in, AEDs highlight a discrepancy between the stated Hong Kong Hospital Authority policy of patient-centered care and the reality of contemporary Hong Kong emergency practice

The significance of circulating tumor cells in prostate cancer patients undergoing adjuvant or salvage radiation therapy

Background:Following radical prostatectomy, success of adjuvant and salvage radiation therapy (RT) is dependent on the absence of micrometastatic disease. However, reliable prognostic/predictive factors for determining this are lacking. Therefore, novel biomarkers are needed to assist with clinical decision-making in this setting. Enumeration of circulating tumor cells (CTCs) using the regulatory-approved CellSearch System (CSS) is prognostic in metastatic prostate cancer. We hypothesize that CTCs may also be prognostic in the post-prostatectomy setting. Methods:Patient blood samples (n=55) were processed on the CSS to enumerate CTCs at 0, 6, 12 and 24 months after completion of RT. CTC values were correlated with predictive/prognostic factors and progression-free survival.Results:CTC status (presence/absence) correlated significantly with positive margins (increased likelihood of CTC neg disease; P=0.032), and trended toward significance with the presence of seminal vesicle invasion (CTC pos; P=0.113) and extracapsular extension (CTC neg; P=0.116). Although there was a trend toward a decreased time to biochemical failure (BCF) in baseline CTC-positive patients (n=9), this trend was not significant (hazard ratio (HR)=0.3505; P=0.166). However, CTC-positive status at any point (n=16) predicted for time to BCF (HR=0.2868; P=0.0437).Conclusions:One caveat of this study is the small sample size utilized (n=55) and the low number of patients with CTC-positive disease (n=16). However, our results suggest that CTCs may be indicative of disseminated disease and assessment of CTCs during RT may be helpful in clinical decision-making to determine, which patients may benefit from RT versus those who may benefit more from systemic treatments

Responsibility modelling for civil emergency planning

This paper presents a new approach to analysing and understanding civil emergency planning based on the notion of responsibility modelling combined with HAZOPS-style analysis of information requirements. Our goal is to represent complex contingency plans so that they can be more readily understood, so that inconsistencies can be highlighted and vulnerabilities discovered. In this paper, we outline the framework for contingency planning in the United Kingdom and introduce the notion of responsibility models as a means of representing the key features of contingency plans. Using a case study of a flooding emergency, we illustrate our approach to responsibility modelling and suggest how it adds value to current textual contingency plans

GT2005-69034 HEAT TRANSFER AND AERODYNAMICS OF TURBINE BLADE TIPS IN A LINEAR CASCADE

Abstract Local measurements of the heat transfer coefficient and pressure coefficient were conducted on the tip and near tip region of a generic turbine blade in a five-blade linear cascade. Two tip clearance gaps were used: 1.6% and 2.8% chord. Data was obtained at a Reynolds number of 2.3 x 10 5 based on exit velocity and chord. Three different tip geometries were investigated: a flat (plain) tip, a suction-side squealer, and a cavity squealer. The experiments reveal that the flow through the plain gap is dominated by flow separation at the pressureside edge and that the highest levels of heat transfer are located where the flow reattaches on the tip surface. High heat transfer is also measured at locations where the tip-leakage vortex has impinged onto the suction surface of the aerofoil. The experiments are supported by flow visualisation computed using the CFX CFD code which has provided insight into the fluid dynamics within the gap. The suction-side and cavity squealers are shown to reduce the heat transfer in the gap but high levels of heat transfer are associated with locations of impingement, identified using the flow visualisation and aerodynamic data. Film cooling is introduced on the plain tip at locations near the pressure-side edge within the separated region and a net heat flux reduction analysis is used to quantify the performance of the successful cooling design

Flow visualisation experiments on sports balls

AbstractFluid dynamics plays a significant role in many sports, principally affecting the trajectory of the associated ball. Boundary layer theory can be used to explain why some of these effects take place, demonstrated here for the games of cricket and golf.The asymmetric nature of a cricket ball, due to the presence of a seam, causes the boundary layer to be tripped into turbulence on one side. On the other hemisphere, the smooth surface promotes laminar flow which separates at a smaller angle relative to the stagnation point. This results in a net pressure force and lateral movement known as swing. In golf inverted dimples are applied to the ball to reduce drag by promoting transition to turbulent flow, this in turn increases the maximum achievable range.In this study, scaled versions of a smooth sphere, a cricket ball and a golf ball were used to perform wind tunnel experiments in which these fluid dynamic effects were demonstrated. A novel infrared flow visualisation technique, in conjunction with measurements of pressure, highlighted the fluid mechanics at the representative conditions found in each sport. The results underlined the dependence on surface roughness, and provided qualitative visual evidence of the state of the boundary layer at a Reynolds number of 1 x 105