62,746 research outputs found
(WP 2016-06) The Effectiveness of Central Bank Forward Guidance under Inflation and Price-Level Targeting
This paper examines the effectiveness of central bank forward guidance under inflation and price-level targeting monetary policies. The results show that the attenuation of the effects of forward guidance can be solved if a central bank switches from inflation targeting to price-level targeting. Output and inflation respond more favorably to forward guidance with price-level targeting than inflation targeting. A monetary policy rule that aggressively reacts to inflation and includes interest rate inertia narrows the performance gap between the two policy regimes. However, forward guidance with price-level targeting is still preferred to forward guidance with inflation targeting after performing multiple robustness checks
Airplane wing leading edge variable camber flap
The invention and design of an aerodynamic high lift device which provided a solution to an aircraft performance problem are described. The performance problem of converting a high speed cruise airfoil into a low speed aerodynamic shape that would provide landing and take-off characteristics superior to those available with contemporary high lift devices are addressed. The need for an improved wing leading edge device that would complement the high lift performance of a triple slotted trailing edge flap is examined. The mechanical and structural aspects of the variable camber flap are discussed and the aerodynamic performance aspects only as they relate to the invention and design of the device are presented
Evaluation of fit for 3D printed retainers as compared to thermoform retainers
ABSTRACT
EVALUATION OF FIT FOR 3D PRINTED RETAINERS AS COMPARED TO THERMOFORM RETAINERS
By David Cole, D.M.D.
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University
Thesis Directors: Eser Tüfekçi, D.D.S., M.S., Ph.D., M.S.H.A.
Professor, Department of Orthodontics
Sompop Bencharit, D.D.S., M.S., Ph.D.
Associate Professor and Director of Digital Dentistry, Department of General Practice
Introduction: Despite recent advances in three-dimensional (3D) printing, little information is available on 3D printed retainers
Methods: Three reference models were used to fabricate traditional vacuum formed, commercially-available vacuum formed, and 3D printed retainers. For each model, three retainers were made using the three methods (a total of 27 retainers). To determine the trueness, the distances between the intaglio surface of the retainers and the occlusal surface of the reference models were measured using an engineering software. A small difference was indicative of a good fit.
Results: Average differences of the traditional vacuum formed retainers ranged from 0.10 to 0.20mm. The commercially-available and 3D printed retainers had a range of 0.10 to 0.30mm and 0.10 to 0.40mm, respectively.
Conclusions: The traditional vacuum formed retainers showed the least amount of deviation from the original reference models while the 3D printed retainers showed the greatest deviation
The Effectiveness of Central Bank Forward Guidance Under Inflation and Price-level Targeting
This paper examines the effectiveness of central bank forward guidance under inflation and price-level targeting monetary policies. The results show that the beneficial effects of forward guidance increase if a central bank pursues price-level targeting instead of inflation targeting. Output and inflation respond more favorably to forward guidance with price-level targeting than inflation targeting. A monetary policy rule that aggressively reacts to inflation and includes interest rate inertia narrows the performance gap between the two policy regimes. However, forward guidance with price-level targeting is still preferred to forward guidance with inflation targeting after performing multiple robustness checks
(WP 2016-02) The Limits of Central Bank Forward Guidance under Learning
Central bank forward guidance emerged as a pertinent tool for monetary policymakers since the Great Recession. Nevertheless, the effects of forward guidance remain unclear. This paper investigates the effectiveness of forward guidance while relaxing two standard macroeconomic assumptions: rational expectations and frictionless financial markets. Agents forecast future macroeconomic variables via either the rational expectations hypothesis or a more plausible theory of expectations formation called adaptive learning. A standard Dynamic Stochastic General Equilibrium (DSGE) model is extended to include the financial accelerator mechanism. The results show that the addition of financial frictions amplifies the differences between rational expectations and adaptive learning to forward guidance. The macroeconomic variables are overall more responsive to forward guidance under rational expectations than under adaptive learning. During a period of economic crisis (e.g. a recession), output under rational expectations displays more favorable responses to forward guidance than under adaptive learning. These differences are exacerbated when compared to a similar analysis without financial frictions. Thus, monetary policymakers should consider the way in which expectations and credit frictions are modeled when examining the effects of forward guidance
Reply to determining structural identifiability of parameter learning machines
The paper Ran and Hu (2014, Neurocomputing) examines identifiability and parameter redundancy in classes of models used in machine learning. This note discusses the results on global identifiability and also clarifies that the paper's results on parameter redundancy already exist in the paper Cole et al. (2010, Mathematical Biosciences)
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Enhancing the employability of Brunel students: Assessment and evaluation of a Level 1 multidisciplinary project based teaching activity in the School of Engineering and Design
The Level 1 Multidisciplinary Project (MDP) is a weeklong project that takes place in the last week of Term 1. It involves first year undergraduate students from across the School subject areas of Electronic and Computer Engineering, Mechanical Engineering, Civil Engineering and Design. The project is designed to be a teaching activity that removes the barrier of academic ability by involving a non‐discipline technical element, the primary emphasis being on the development of key transferable skills and the utilisation of problem solving skills that students have begun to develop in their first term at university. Each year around 450 students take part in MDP and they are put into mixed discipline groups of 8 or 9 students tasked with designing, building and demonstrating Lego Mindstorms and BASIC Stamp micro‐controlled vehicles to tackle an obstacle course. This report presents an analysis of responses from students to an online survey set up to evaluate the MDP. The survey was created using the online ‘SurveyMonkey’ website and was made live on 30th March 2011. The survey consisted of 15 questions, including tick box style quantitative questions along with some text based qualitative questions. There was also a request for contact details to be provided, if students would be happy to be contacted for a follow‐up discussion. The aim of the survey was to obtain feedback from students in each subject area, in each academic year group that has taken part in the MDP in the School of Engineering and Design. The survey was designed to try and assess student experiences and recollections of the project activity, to evaluate how the MDP has evolved over the four years it has taken place and inform the continued development of the MDP in future academic years. Information about the survey was sent by email to all students that have participated in the MDP since it was introduced in the 2007/2008 academic year (approximately 1700 students). The emails were written by Dr David Smith who is responsible for the running of the MDP and Dr Jo Cole who is involved in the co‐ordination of the MDP, inviting students to complete the online questionnaire. This report is broken into sections, giving an overview of the survey results as a whole, before looking at key observations in the data by year and by subject area. The survey questions are given in Appendix A with summary charts of the tick box responses given in Appendix B and the raw data from all questions provided by SurveyMonkey in Appendix C. Key points raised in the follow‐up one to‐one email and phone discussions are then presented, with full transcripts of the questions and answers from these discussions given in Appendix D, along with feedback from the professional bodies that accredit the different undergraduate courses taking part in the MDP and the view of the Brunel Placement and Careers Office. A list of conclusions is then given, drawn up to reflect the aspects of the MDP that need improvement, to be used as input to the development of the MDP for the coming academic year. Collation of the survey data, follow‐up discussions with students and initial preparation of this report were conducted by Dianna Reid, with funding provided by the Brunel Academic Practice and Development Unit as part of a 2011 Learning and Teaching Innovation Fund award under project code 2LA026
A note on the identifiability of certain latent class models
Wiering (2005, Statistics and Probability Letters, 75, 211-218) provides conditions
for the identifiability of a class of latent models. Here we derive an alternative more
general method of proving this result, which is based on standard identi¯ability
methods involving forming Jacobians
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