THE importance of the aircraft engine supercharger is being emphasized by the increasing demands for high altitude performance in the present war. Centrifugal stresses of…
Abstract
THE importance of the aircraft engine supercharger is being emphasized by the increasing demands for high altitude performance in the present war. Centrifugal stresses of considerable magnitude are induced in the supercharger impeller by reason of the high rotative speeds necessary to obtain the desired pumping effect. A speed of 20,000 r.p.m. is not uncommon for an impeller of 12 in. outside diameter and over. Consequently, a knowledge of the centrifugal stresses constitutes a basic design consideration. Unfortunately, a direct determination of these stresses is not an easy matter.
Burden transport is a ubiquitous primate behavior. Modern humans, however, take this primate tendency and extend it to a behavioral repertoire that influences many of our daily…
Abstract
Burden transport is a ubiquitous primate behavior. Modern humans, however, take this primate tendency and extend it to a behavioral repertoire that influences many of our daily activities and almost certainly helped shape our physical and behavioral form. I examine the transportation of food in the context of central place foraging, from the perspective of maximizing energy acquisition. A detailed model of the energetic cost of burden transport is presented and its sensitivity to the variables of body mass, burden mass, terrain, incline and velocity discussed.
Sometimes beam cross‐sections with strange geometries occur. Then it is tedious to calculate the values which are needed for a beam analysis, such as the area, the centre of…
Abstract
Sometimes beam cross‐sections with strange geometries occur. Then it is tedious to calculate the values which are needed for a beam analysis, such as the area, the centre of gravity, the inertia‐, centrifugal‐and polar moments, the position of the main inertia axes, and the resistance moments. It might also be of interest to observe the changing of these values if the cross‐section is rotated. This paper gives a program executing these tasks using numerical methods. The program is in C since this language is of growing interest to modern programmers.
The paper's purpose is to promote the use of modern technologies such as multimedia packages to engineering students. The aim is to help them to learning in their learning…
Abstract
Purpose
The paper's purpose is to promote the use of modern technologies such as multimedia packages to engineering students. The aim is to help them to learning in their learning, visualization, problem solving and understanding engineering concepts such as in mechanics dynamics.
Design/methodology/approach
TAPS packages are developed to help students solve selected engineering problems in a step‐by‐step approach. A comparison is made with existing commercial engineering packages to see if TAPS packages could further enhance the learning process.
Findings
The differences found were indicative of better presentation and clarity, step‐by‐step approach to solve engineering problems, user‐friendly environment, unbiased assessment of performance and flexibility to incorporate 3‐D geometric models in the TAPS packages.
Research limitations/implications
The TAPS packages were compared with two commercial engineering packages and were based on a small number of users. A larger sample size of students would be required to see if TAPS packages are productive enough to be used locally in Malaysian universities and higher learning institutions.
Originality/value
The main originality of the paper can be seen from the development of the TAPS packages and the comparative study with existing commercial engineering packages. The differences found are explained in details in this paper.
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Application of the discrete element method (DEM) to real scale engineering problems involving three‐dimensional modelling of large, non‐spherical particles must consider the…
Abstract
Application of the discrete element method (DEM) to real scale engineering problems involving three‐dimensional modelling of large, non‐spherical particles must consider the inertia tensor and temporal change in the orientation of the particles when calculating the rotational motion. This factor has commonly been neglected in discrete element modelling although it will significantly influence the dynamic behaviour of non‐spherical particles. In this paper two methods, vector transformation and tensor transformation, for calculation of the rotational motion of particles in response to applied moments are presented. The methods consider the inertia tensor and the local object frame of arbitrary shaped particles and suggest solutions for the non‐linear Euler equations for calculation of their rotational motion. They are discussed with respect to implementation into a discrete element code and assessed in terms of their accuracy and computational efficiency.
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This paper aims to present the development of technology‐assisted problem solving (TAPS) packages at University Tenaga Nasional (UNITEN). The project is the further work of the…
Abstract
Purpose
This paper aims to present the development of technology‐assisted problem solving (TAPS) packages at University Tenaga Nasional (UNITEN). The project is the further work of the development of interactive multimedia based packages targeted for students having problems in understanding the subject of engineering mechanics dynamics.
Design/methodology/approach
In this study TAPS packages are compared with other selected engineering computer packages.
Findings
The differences found were indicative of better presentation and clarity, step‐by‐step approach to solve engineering problems, user‐friendly environment, unbiased assessment of performance and flexibility to incorporate 3‐D geometric models in the TAPS packages.
Originality/value
This paper provides a brief account of the differences between the TAPS packages approach used in this research with that of commercial simulation packages accompanying the engineering mechanics dynamics textbook and will be of interest to those in the field of engineering.
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Louwrens J. Butler and Glen Bright
This paper aims to examine the structure of the control strategy that is being deployed on the control of the mobile materials handling platform, from the higher level onboard…
Abstract
Purpose
This paper aims to examine the structure of the control strategy that is being deployed on the control of the mobile materials handling platform, from the higher level onboard interface software to the low‐level control system that is tasked with the dynamic stability of the platform.
Design/methodology/approach
The application of the principle of the inverted pendulum in mobile robotics has only recently been made possible by advances in the technology of electronics. A mobile materials handling platform has been designed and built for use in manufacturing systems of the future. The principle of the inverted pendulum has been incorporated into the design. This means that the platform is able to maintain dynamic stability during specific periods of operation. The mechatronic engineering approach was adopted in the design of the platform, which produced an integrated embedded system.
Findings
Open source software being implemented onboard the platform for interfacing between the platform and remote client computers is found to be easily customisable according to the requirements of one's application. A solution to the problem of nonholonomic motion constraints that concern any differential drive mobile robot was found in a nonlinear state transformation algorithm. The algorithm was implemented on an intermediate level between the interface software and the low‐level control system. The low‐level feedback control system was designed using a linear quadratic regulator design method. Simulations of this control system showed that it was robust enough to reject predetermined disturbances in system characteristics.
Originality/value
The application of a mobile platform specifically designed for materials handling based on the principle of the inverted pendulum has not been attempted to date.
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Pedro Miguel de Almeida Areias, Timon Rabczuk and Joaquim Infante Barbosa
– The purpose of this paper is to discuss the linear solution of equality constrained problems by using the Frontal solution method without explicit assembling.
Abstract
Purpose
The purpose of this paper is to discuss the linear solution of equality constrained problems by using the Frontal solution method without explicit assembling.
Design/methodology/approach
Re-written frontal solution method with a priori pivot and front sequence. OpenMP parallelization, nearly linear (in elimination and substitution) up to 40 threads. Constraints enforced at the local assembling stage.
Findings
When compared with both standard sparse solvers and classical frontal implementations, memory requirements and code size are significantly reduced.
Research limitations/implications
Large, non-linear problems with constraints typically make use of the Newton method with Lagrange multipliers. In the context of the solution of problems with large number of constraints, the matrix transformation methods (MTM) are often more cost-effective. The paper presents a complete solution, with topological ordering, for this problem.
Practical implications
A complete software package in Fortran 2003 is described. Examples of clique-based problems are shown with large systems solved in core.
Social implications
More realistic non-linear problems can be solved with this Frontal code at the core of the Newton method.
Originality/value
Use of topological ordering of constraints. A-priori pivot and front sequences. No need for symbolic assembling. Constraints treated at the core of the Frontal solver. Use of OpenMP in the main Frontal loop, now quantified. Availability of Software.
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Gretchen Stolte, Noel Zaro and Kaylynn Zaro
This chapter focuses on creating a Torres Strait Island perspective on the research ethics and cultural protocols of Islander dance. Previous research into Torres Strait Islander…
Abstract
This chapter focuses on creating a Torres Strait Island perspective on the research ethics and cultural protocols of Islander dance. Previous research into Torres Strait Islander cultural dance has traditionally focussed on the music and songs and rarely on the movements themselves or the cultural protocols of dance. Specifically, we explore how Islander dance from the Island of Mer (Meriam Kab) is not only created and practised but also how that information is communicated. This chapter asks the questions – how should Meriam Kab be researched? What are the protocols and processes that need to be followed? What is the role of Elders and how important is their place in the practice of dance? These questions will be explored through the cultural dances performed by the Gerib Sik Torres Strait Islander Corporation as an inroad into the significance of Meriam Kab as expressions of Meriam identity. Gerib Sik has a long tradition of cultural consultation in the development of their dances, and this chapter is co-authored by the directors. Through this writing, we hope to shine a spotlight on Meriam Kab research by illustrating the importance of the specificity of Islander identity.
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There is a long history of school failure for Aboriginals1 in the U.S. educational system. Culturally relevant/responsive pedagogy affords opportunities for Aboriginal students to…
Abstract
There is a long history of school failure for Aboriginals1 in the U.S. educational system. Culturally relevant/responsive pedagogy affords opportunities for Aboriginal students to achieve academic success through building upon their cultural heritages and Native ways of knowing. School systems adopting this pedagogy empower Indigenous students to connect with essential knowledge for academic success in today’s world. This enhanced pedagogy creates classrooms of involvement that promote Aboriginal students’ achievement. Preservice teachers employing this pedagogy will experience success with their Indigenous students and learn about Aboriginal communities, lifeways, and values. Mutual respect is engendered as long-perpetuated negative stereotypes of Native Americans are undone. Culturally relevant/responsive pedagogy can be tailored to specific populations by incorporating their own Aboriginal knowledge, languages, and practices into teaching praxis.