The modeling of diffuse boundaries in the 2-D digital waveguide mesh

The digital waveguide mesh can be used to simulate the propagation of sound waves in an acoustic system. The accurate simulation of the acoustic characteristics of boundaries within such a system is an important part of the model. One significant property of an acoustic boundary is its diffusivity. Previous approaches to simulating diffuse boundaries in a digital waveguide mesh are effective but exhibit limitations and have not been analyzed in detail. An improved technique is presented here that simulates diffusion at boundaries and offers a high degree of control and consistency. This technique works by rotating wavefronts as they pass through a special diffusing layer adjacent to the boundary. The waves are rotated randomly according to a chosen probability function and the model is lossless. This diffusion model is analyzed in detail, and its diffusivity is quantified in the form of frequency dependent diffusion coefficients. The approach used to measuring boundary diffusion is described here in detail for the 2-D digital waveguide mesh and can readily be extended for the 3-D case

Language tutors at the OUUK – their (e)-competencies in Open and Distance Learning

The OUUK has been teaching distance courses in languages for more than ten years. Students learn by means of specially-designed course materials, increasingly web-based resources and through direct interaction with tutors, who provide personalised feedback on the students’ assignments as well as offering tutorials for communicative practice. The role of OUUK tutors embraces, however, more than just teaching and giving feedback. They play a central role in supporting students in every aspect of their learning, forming the interface between the institution and the learner. The importance of the tutor role in ODL in general has been the subject of some informative research, but much less has been written about the skills needed by tutors of languages at a distance. This international research project has been set up to address this shortfall, and to gather evidence and insights into this particular role. The project aims to investigate the skills, attributes and (e-)competencies required by language tutors of whom a substantial number deliver the tuition online. Initially, a selected group of OUUK language tutors generated what they perceived to be the knowledge, skills and attributes necessary to carry out this complex and demanding role which included the requisite skills for online tuition delivery. In the next stage the outcomes they had produced were refined and regrouped by the researchers. In the third stage a wider sample of tutors commented and added to the listings. This paper will report on the findings so far and summarise the next stages which are planned

Acoustic modeling using the digital waveguide mesh

The digital waveguide mesh has been an active area of music acoustics research for over ten years. Although founded in 1-D digital waveguide modeling, the principles on which it is based are not new to researchers grounded in numerical simulation, FDTD methods, electromagnetic simulation, etc. This article has attempted to provide a considerable review of how the DWM has been applied to acoustic modeling and sound synthesis problems, including new 2-D object synthesis and an overview of recent research activities in articulatory vocal tract modeling, RIR synthesis, and reverberation simulation. The extensive, although not by any means exhaustive, list of references indicates that though the DWM may have parallels in other disciplines, it still offers something new in the field of acoustic simulation and sound synth

Clinical presentation and management of right ventricular dysfunction

No abstract available

The right ventricle—structural and functional importance for anaesthesia and intensive care

No abstract available

Collaborating to Support Student Success: Exploring Free e-Text Access at Illinois State University

A number of studies have shown a connection between the cost of textbooks and student success in higher education. While Milner Library has traditionally contributed to student success on many levels, we wished to address particular challenges to student success and equity that have been magnified by COVID. In Fall 2020 a project team of librarians from a variety of departments secured funding for a coordinated effort to license available e-textbooks for Spring 2021 courses. Major goals of this project are to help alleviate textbook costs for students and explore the potential impact of these savings on student success. In this panel, we will describe project planning and progress to date, share some preliminary findings, and emphasize the contributions brought by each librarian’s role and specialized knowledge

Impulse Response Estimation for the Auralisation of Vehicle Engine Sounds Using Dual Channel FFT Analysis

A method is presented to estimate the impulse response of a filter that describes the transformation in sound that takes place between a close-mic recording of a vehicle engine and the sound of the same engine at another point in or near to the vehicle. The proposed method makes use of the Dual Channel FFT Analysis technique and does not require the use of loudspeakers, computer modelling or mechanical devices. Instead, a minimum of two microphones is required and the engine itself is used as the source of sound. This is potentially useful for virtual reality applications or in sound design for computer games, where users select their virtual position at points inside or outside the vehicle. A case study is described to examine the method in practice and the results are discussed. The described method can be readily extended for surround sound applications using spatial microphone array recording techniques