A large-scale computing infrastructure for design education

Most departmental computing infrastructure reflects the state of networking technology and available funds at the time of construction, which converge in a preconceived notion of homogeneity of network architecture and usage patterns. The DMAN (Digital Media Access Network) project, a large-scale server and network foundation for the Hong Kong Polytechnic University's School of Design was created as a platform that would support a highly complex academic environment while giving maximum freedom to students, faculty and researchers through simplicity and ease of use. As a centralized multi-user computation backbone, DMAN faces an extremely hetrogeneous user and application profile, exceeding implementation and maintenance challenges of typical enterprise, and even most academic server set-ups. This paper sumarizes the specification, implementation and application of the system while describing its significance for design education in a computational context.

A generative design system based on evolutionary and mathematical functions

Previous work by Professor John Frazer on Evolutionary Architecture provides a basis for the development of a system evolving architectural envelopes in a generic and abstract manner. Recent research by the authors has focused on the implementation of a virtual environment for the automatic generation and exploration of complex forms and architectural envelopes based on solid modelling techniques and the integration of evolutionary algorithms, enhanced computational and mathematical models. Abstract data types are introduced for genotypes in a genetic algorithm order to develop complex models using generative and evolutionary computing techniques. Multi-objective optimisation techniques are employed for defining the fitness function in the evaluation process.

An evolutionary framework for enhancing design

A computational framework for enhancing design in an evolutionary approach with a dynamic hierarchical structure is presented in this paper. This framework can be used as an evolutionary kernel for building computer-supported design systems. It provides computational components for generating, adapting and exploring alternative design solutions at multiple levels of abstraction with hierarchically structured design representations. In this paper, preliminary experimental results of using this framework in several design applications are presented.

Creative design and the generative evolutionary paradigm

Design as seen from the designer's perspective is a series of amazing imaginative jumps or creative leaps. But design as seen by the design historian is a smooth progression or evolution of ideas that they seem self-evident and inevitable after the event. But the next step is anything but obvious for the artist/creator/inventor/designer stuck at that point just before the creative leap. They know where they have come from and have a general sense of where they are going, but often do not have a precise target or goal. This is why it is misleading to talk of design as a problem-solving activity - it is better defined as a problem-finding activity. This has been very frustrating for those trying to assist the design process with computer-based, problem-solving techniques. By the time the problem has been defined, it has been solved. Indeed the solution is often the very definition of the problem. Design must be creative-or it is mere imitation. But since this crucial creative leap seem inevitable after the event, the question must arise, can we find some way of searching the space ahead? Of course there are serious problems of knowing what we are looking for and the vastness of the search space. It may be better to discard altogether the term "searching" in the context of the design process: Conceptual analogies such as search, search spaces and fitness landscapes aim to elucidate the design process. However, the vastness of the multidimensional spaces involved make these analogies misguided and they thereby actually result in further confounding the issue. The term search becomes a misnomer since it has connotations that imply that it is possible to find what you are looking for. In such vast spaces the term search must be discarded. Thus, any attempt at searching for the highest peak in the fitness landscape as an optimal solution is also meaningless. Futhermore, even the very existence of a fitness landscape is fallacious. Although alternatives in the same region of the vast space can be compared to one another, distant alternatives will stem from radically different roots and will therefore not be comparable in any straightforward manner (Janssen 2000). Nevertheless we still have this tantalizing possibility that if a creative idea seems inevitable after the event, then somehow might the process be rserved? This may be as improbable as attempting to reverse time. A more helpful analogy is from nature, where it is generally assumed that the process of evolution is not long-term goal directed or teleological. Dennett points out a common minsunderstanding of Darwinism: the idea that evolution by natural selection is a procedure for producing human beings. Evolution can have produced humankind by an algorithmic process, without its being true that evolution is an algorithm for producing us. If we were to wind the tape of life back and run this algorithm again, the likelihood of "us" being created again is infinitesimally small (Gould 1989; Dennett 1995). But nevertheless Mother Nature has proved a remarkably successful, resourceful, and imaginative inventor generating a constant flow of incredible new design ideas to fire our imagination. Hence the current interest in the potential of the evolutionary paradigm in design. These evolutionary methods are frequently based on techniques such as the application of evolutionary algorithms that are usually thought of as search algorithms. It is necessary to abandon such connections with searching and see the evolutionary algorithm as a direct analogy with the evolutionary processes of nature. The process of natural selection can generate a wealth of alternative experiements, and the better ones survive. There is no one solution, there is no optimal solution, but there is continuous experiment. Nature is profligate with her prototyping and ruthless in her elimination of less successful experiments. Most importantly, nature has all the time in the world. As designers we cannot afford prototyping and ruthless experiment, nor can we operate on the time scale of the natural design process. Instead we can use the computer to compress space and time and to perform virtual prototyping and evaluation before committing ourselves to actual prototypes. This is the hypothesis underlying the evolutionary paradigm in design (1992, 1995).

The way forward : report on the preparatory phase of prefabricated building design and construction methodology: identifying critical issues and recommending the way forward

This is an initial report of the PolyU SD part of the team to study Pre-fabricated Building Design and Construction Methodology and marks the completion of Phase 1. It follows our first notes prepared for the meeting on 2 February that identified some critical issues including future lifestyles, life expectancy of buildings, sustainability, size, flexibility and planning considerations. It is also an expansion of our presentation in Dongguan on 23 February. It is not a comprehensive survey of existing approaches or possible ways forward, but it has homed in on certain specific issues and does give specific examples to make the suggestions concrete. It is recommended that more comprehensive research be done to establish previous work and experience internationally. It is also recommended that more research be done on lifestyles as a preliminary to developing at least three concepts for evaluation before proceeding to the detailed design of one concept for full prototyping and market testing. The goal at this point is not to define a single direction but to suggest several future trajectories for further consideration. By the same token, this report is not intended as an exhaustive description of the considerable base of knowledge and ideas brought by the PolyU team to this exciting task. Before taking on an issue of this magnitude and importance in the definition of Hong Kong's future, one must carry out a thoughtful analysis of the issues at hand and an informed definition of paradigms, directions, goals and methods whereby our energies can be best used in the next steps. This report is the result of this analysis

Development of a Rep-inducible, BBTV-based expression system in banana

Banana bunchy top is regarded as the most important viral disease of banana, causing significant yield losses worldwide. The disease is caused by Banana bunchy top virus (BBTV), which is a circular ssDNA virus belonging to the genus Babuvirus in the family Nanoviridae. There are currently few effective control strategies for this and other ssDNA viruses. “In Plant Activation” (InPAct) is a novel technology being developed at QUT for ssDNA virus-activated suicide gene expression. The technology exploits the rolling circle replication mechanism of ssDNA viruses and is based on a unique “split” gene design such that suicide gene expression is only activated in the presence of the viral Rep. This PhD project aimed to develop a BBTV-based InPAct system as a suicide gene strategy to control BBTV. The BBTV-based InPAct vector design requires a BBTV intergenic region (IR) to be embedded within an intron in the gene expression cassette. To ensure that the BBTV IR would not interfere with intron splicing, a TEST vector was initially generated that contained the entire BBTV IR embedded within an intron in a β-glucuronidase (GUS) expression vector. Transient GUS assays in banana embryogenic cell suspensions indicated that cryptic intron splice sites were present within the IR. Transcript analysis revealed two cryptic intron splice sites in the Domain III sequence of the CR-M within the IR. Removal of the CR-M from the TEST vector resulted in an enhancement of GUS expression suggesting that the cryptic intron splice sites had been removed. An InPAct GUS vector was subsequently generated that contained the modified BBTV IR, with the CR-M (minus Domain III) repositioned within the InPAct cassette. Using transient histochemical and fluorometric GUS assays in banana embryogenic cells, the InPAct GUS vector was shown to be activated in the presence of the BBTV Rep. However, the presence of both BBTV Rep and Clink was shown to have a deleterious effect on GUS expression suggesting that these proteins were cytotoxic at the levels expressed. Analysis of replication of the InPAct vectors by Southern hybridisation revealed low levels of InPAct cassette-based episomal DNA released from the vector through the nicking/ligation activity of BBTV Rep. However, Rep-mediated episomal replicons, indicative of rolling circle replication of the released circularised cassettes, were not observed. The inability of the InPAct cassette to be replicated was further investigated. To examine whether the absence of Domain III of the CR-M was responsible, a suite of modified BBTV-based InPAct GUS vectors was constructed that contained the CR-M with the inclusion of Domain III, the CR-M with the inclusion of Domain III and additional upstream IR sequence, or no CR-M. Analysis of replication by Southern hybridisation revealed that neither the presence of Domain III, nor the entire CR-M, had an effect on replication levels. Since the InPAct cassette was significantly larger than the native BBTV genomic components (approximately 1 kb), the effect of InPAct cassette size on replication was also investigated. A suite of size variant BBTV-based vectors was constructed that increased the size of a replication competent cassette to 1.1 kbp through to 2.1 kbp.. Analysis of replication by Southern hybridisation revealed that an increase in vector size above approximately 1.5 - 1.7 kbp resulted in a decrease in replication. Following the demonstration of Rep-mediated release, circularisation and expression from the InPAct GUS vector, an InPAct vector was generated in which the uidA reporter gene was replaced with the ribonuclease-encoding suicide gene, barnase. Initially, a TEST vector was generated to assess the cytotoxicity of Barnase on banana cells. Although transient assays revealed a Barnase-induced cytotoxic effect in banana cells, the expression levels were sub-optimal. An InPAct BARNASE vector was generated and tested for BBTV Rep-activated Barnase expression using transient assays in banana embryogenic cells. High levels of background expression from the InPAct BARNASE vector made it difficult to accurately assess Rep-activated Barnase expression. Analysis of replication by Southern hybridisation revealed low levels of InPAct cassette-based episomal DNA released from the vector but no Rep-mediated episomal replicons indicative of rolling circle replication of the released circularised cassettes were again observed. Despite the inability of the InPAct vectors to replicate to enable high level gene expression, the InPAct BARNASE vector was assessed in planta for BBTV Rep-mediated activation of Barnase expression. Eleven lines of transgenic InPAct BARNASE banana plants were generated by Agrobacterium-mediated transformation and were challenged with viruliferous Pentalonia nigronervosa. At least one clonal plant in each line developed bunchy top symptoms and infection was confirmed by PCR. No localised lesions were observed on any plants, nor was there any localised GUS expression in the one InPAct GUS line challenged with viruliferous aphids. The results presented in this thesis are the first study towards the development of a BBTV-based InPAct system as a Rep-activatable suicide gene expression system to control BBTV. Although further optimisation of the vectors is necessary, the preliminary results suggest that this approach has the potential to be an effective control strategy for BBTV. The use of iterons within the InPAct vectors that are recognised by Reps from different ssDNA plant viruses may provide a broad-spectrum resistance strategy against multiple ssDNA plant viruses. Further, this technology holds great promise as a platform technology for the molecular farming of high-value proteins in vitro or in vivo through expression of the ssDNA virus Rep protein.

Making sense of an everyday science text : linguistic, visual and spatial design

In this article, we take a close look at the literacy demands of one task from the ‘Marvellous Micro-organisms Stage 3 Life and Living’ Primary Connections unit (Australian Academy of Science, 2005). One lesson from the unit, ‘Exploring Bread’, (pp 4-8) asks students to ‘use bread labels to locate ingredient information and synthesise understanding of bread ingredients’. We draw upon a framework offered by the New London Group (2000), that of linguistic, visual and spatial design, to consider in more detail three bread wrappers and from there the complex literacies that students need to interrelate to undertake the required task. Our findings are that although bread wrappers are an example of an everyday science text, their linguistic, visual and spatial designs and their interrelationship are not trivial. We conclude by reinforcing the need for teachers of science to also consider how the complex design elements of everyday science texts and their interrelated literacies are made visible through instructional practice.