Jane Chu, Sarah Engelbrecht, Gregory Graf and David W. Rosen
The purpose of this paper is to investigate design synthesis methods for designing lattice cellular structures to achieve desired stiffnesses. More generally, to find appropriate…
Abstract
Purpose
The purpose of this paper is to investigate design synthesis methods for designing lattice cellular structures to achieve desired stiffnesses. More generally, to find appropriate design problem formulations and solution algorithms for searching the large, complex design spaces associated with cellular structures.
Design/methodology/approach
Two optimization algorithms were tested: particle swarm optimization (PSO) and Levenburg‐Marquardt (LM), based on a least‐squares minimization formulation. Two example problems of limited complexity, specifically a two‐dimensional cantilever beam and a two‐dimensional simply‐supported plate, were investigated. Computational characteristics of the algorithms were reported for design problems with hundreds of variables. Constraints from additive manufacturing processes were incorporated to ensure that resulting designs are realizable.
Findings
Both PSO and LM succeeded in searching the design spaces and finding good designs. LM is one to two orders of magnitude more efficient for this class of problems.
Research limitations/implications
Three‐dimensional problems are not investigated in this paper.
Practical implications
LM appears to be a viable algorithm for optimizing structures of complex geometry for minimum weight and desired stiffness.
Originality/value
The testing of design synthesis methods (problem formulations and algorithms) for lattice cellular structures, and the testing of PSO and LM algorithms, are of particular value.
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Marinda Neethling, Elsabé Wessels and Petra Engelbrecht
The birth of a non-racial and democratic South Africa in 1994 created great anticipation that society and education operating under the Apartheid government would be transformed…
Abstract
The birth of a non-racial and democratic South Africa in 1994 created great anticipation that society and education operating under the Apartheid government would be transformed. Education policies and education guidelines based on the South African Constitution now acknowledge the rights of all students from diverse backgrounds and abilities to access quality regular education. Against the background of Goal 4 of the United Nations Sustainable Development Goals, this chapter analyses initial and more recent policies and implementation guidelines to develop an equitable inclusive education system to identify barriers to inclusive education and possible levers for change.
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Alien franchise protagonist Ellen Ripley (Sigourney Weaver) returns in the series' second film instalment, Aliens (1986), as ‘a full-fledged hard-body hero’ (Gallardo & Smith, 2004…
Abstract
Alien franchise protagonist Ellen Ripley (Sigourney Weaver) returns in the series' second film instalment, Aliens (1986), as ‘a full-fledged hard-body hero’ (Gallardo & Smith, 2004) to assist in the rescue of a group of colonists from an Alien invasion. As each of the rescue team's male officers are killed or proven incompetent or traitorous, Ripley quickly steps forward as the surviving group's leader and principal strategist, forming a strong emotional attachment to the colonists' only surviving child and providing structure and stability to the remaining soldiers. Her heroism is defined by her maternal leadership of the group; as the most sensible and competent member, she prioritizes the group's needs above her own. Ripley's full embodiment of motherhood amplifies her machoism and maternal control over the surviving group, allowing her to reconquer her fears of the Alien species and protect her adopted child when she is kidnapped and nearly killed by the Alien Queen. This chapter thus traces Ellen Ripley's transformation from sceptical consultant to macho-mother and its importance to the franchise's overarching narrative, as well as the evolution of the macho-mother hero in more recent science fiction action films such as Mad Max Fury Road (2015) and The Cloverfield Paradox (2018).
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Richard Rose and Michael Shevlin
Significant progress towards the provision of a more equitable and inclusive education system in Ireland has been made in recent years. Through an interrogation of the research…
Abstract
Significant progress towards the provision of a more equitable and inclusive education system in Ireland has been made in recent years. Through an interrogation of the research that has influenced changes in national policy and practices, this chapter includes a discussion of associated literature, which addresses national inclusive education priorities in Ireland. Building upon a method for reviewing the literature applied in Ireland as part of a major longitudinal study (Rose et al., 2010), a discussion of the current situation is presented in relation to progress towards the Education for All Goals and key issues for further scrutiny are proposed.