Production of Australian freshwater crayfish in earthen-based systems using pelleted diets and forage crops as food

Juvenile Cherax destructor (commonly called theyabby) were cultured in earthen-based ponds and tanks for 70–105d, and were fed pellets and/or a forage crop of the perennialwhiteclover, Trifolium repens. Three supplementary feedingstrategies were evaluated. Yabby growth on pellets consistently exceeded (by67–159%) that obtained on clover. Base-line yields for extensiveproduction systems are around 400 kg ha^–1. Thesupplementary addition of T. repens produced yields of 635kg ha^–1 (in ponds) to 1086 kgha^–1 (in tanks). The sequential addition of cut-cloverto tanks stimulated growth to levels approaching those achieved on pellets.Yabbies stocked into ponds at 17 m^–2 and fed 33%protein pellets for 100 d, resulted in a yield of 1117 kgha^–1.Pellet inputs at a rate of 129–249 g m^–2(dry matter) and 38–83 g m^–2 (protein) over70–100 d resulted in acceptable growth and feed utilisationindices. Clover inputs of 534–682 g m–2 (asdry matter) or 84–177 g m^–2 (as protein)produced reasonable growth rates but poor feed utilisation indices. Aconsiderable quantity of the dry matter and protein content of clover waseitherinefficiently utilised or directed into other production pathways. In tanks,clover inputs from 113–296 g m^–2 (drymatter) and 24–54 g m^–2 (protein) weresufficient to maintain high growth rates for 4 weeks, while in ponds, inputs of21 g m^–2 (dry matter) and 4.3 gm^–2 (protein) were sufficient for 3 weeks. During theearly weeks of production no growth advantage was gained by providing pelletstoanimals cultured in forage-based systems. Forage depletion occurred after3–4 weeks and was probably a major growth limiting factor.

An observer design procedure for a class of nonlinear time-delay systems

This paper considers a class of uncertain, nonlinear differential state delayed control systems and presents a reduced-order observer design procedure to asymptotically estimate any vector state functionals. The method proposed involves decomposition of the delayed portion of the system into two parts: a matched and mismatched part. Provided that the rank of the mismatched part is less than the number of the outputs, a reduced-order linear functional observer, with any prescribed stability margin, can be constructed by using a simple procedure. A numerical example is given to illustrate the new design procedure and its features.

Partial-state observers for nonlinear systems

This note deals with the design of reduced-order observers for a class of nonlinear systems. The order reduction of the observer is achieved by only estimating a required partial set of the state vector. Necessary and sufficient conditions are derived for the existence of reduced-order observers. An observer design procedure based on linear matrix inequalities is given. A numerical example is given to illustrate the design method.

Dynamical systems for discovering protein complexes and functional modules from biological networks

Recent advances in high throughput experiments and annotations via published literature have provided a wealth of interaction maps of several biomolecular networks, including metabolic, protein-protein, and protein-DNA interaction networks. The architecture of these molecular networks reveals important principles of cellular organization and molecular functions. Analyzing such networks, i.e., discovering dense regions in the network, is an important way to identify protein complexes and functional modules. This task has been formulated as the problem of finding heavy subgraphs, the Heaviest k-Subgraph Problem (k-HSP), which itself is NPhard. However, any method based on the k-HSP requires the parameter k and an exact solution of k-HSP may still end up as a “spurious” heavy subgraph, thus reducing its practicability in analyzing large scale biological networks. We proposed a new formulation, called the rank-HSP, and two dynamical systems to approximate its results. In addition, a novel metric, called the Standard deviation and Mean Ratio (SMR), is proposed for use in “spurious” heavy subgraphs to automate the discovery by setting a fixed threshold. Empirical results on both the simulated graphs and biological networks have demonstrated the efficiency and effectiveness of our proposal.

System of systems approach to threat detection and integration of heterogeneous independently operable systems

This paper presents a system of systems approach to threat detection through integration of heterogeneous independently operable systems. The approach is presented on a realistic situation where a human-controlled base robot, swarm robot(s), and sensors work together to obtain a decision about a possible threat in the environment. The base robot is remotely operated by a human using a haptic control system. The swarm robot(s) are autonomous and can accept directives from the base robot. Finally, sensors directly communicate with (report to) the base robot. In this scenario, heterogeneous systems and human interact in a system of systems architecture. With the inclusion of human expert and sensor verification of swarm robots, the system can successfully perform the threat detection and reduce the false alarms. Finally, a system of systems simulation framework including a base robot, a swarm robot, and two sensors is presented in addition to an experimental evaluation of the proposed SoS architecture

Design of linear functional observers for time-delay systems of the neutral-type

This paper presents the design of reduced-order linear functional observers for a class of linear time-delay systems of the neutral-type. The type of the observer proposed in this paper is without internal delay and its order is the same as the number of linear functions to be estimated. First, conditions for the existence of the reduced-order functional observers that are capable of asymptotically estimating any given function of the state vector are derived. Then, based on the newly derived existence conditions, a procedure is given for the determination of the observer parameters. The results derived in this paper include a range of linear systems and extend some existing results of linear functional observers to linear neutral delay systems. A numerical example is given to illustrate the design procedure.

International examples of large-scale systems-theory and practice IV: B2B e-commerce implementation in the Australian context

Two of the most commonly used classifications in IS research are the factor approach and the process approach. While many studies of IS implementation are undertaken using a factor approach, little research so far examines the process of e-commerce implementation, especially in relation to the implementation of e-commerce in business-to-business (B2B) relationships. A holistic understanding of implementation which combines both the factor and process approaches using a case study method, is suggested as particularly suitable because of its ability to capture the reality of e-commerce implementation in an organisation's natural environment and in much greater detail than is possible using one of these approaches alone. In this paper, therefore, we endeavour to contribute to what we perceive as a gap in the body of theory surrounding the implementation process in the business-to-business e-commerce literature. We describe the findings of multiple case studies involving ten major Australian e-commerce initiators. In addition to confirming our earlier finding of the importance of non-technical factors for the success of the implementation process we also present, through our case studies, the various management and business issues associated with the success or failure of B2B e-commerce implementation.

Design of reduced-order observers for neutral time-delay systems

This paper presents a method for the design of reduced-order observers for a class of linear time-delay systems of the neutral-type. Conditions for the existence of reduced-order observers that are capable of asymptotically estimating any given function of the state vector are derived. A step-by-step design procedure is given for the determination of the observer parameters. A numerical example is given to illustrate the design procedure.

A common disturbance decoupled observer for linear systems with unknown inputs

This paper presents a solution to the problem of designing a common linear functional observer that can observe a partial set of the state vector of two linear systems with unknown inputs. A new structure of a decoupled linear functional observer is proposed for systems subject unknown disturbances, using only the available output information. Existence conditions as well as a design procedure are given for constructing the proposed observer. A numerical example is given to illustrate the effectiveness of the new observer structure.

Fuzzy neural networks for control of dynamic systems

This thesis provides a unified and comprehensive treatment of the fuzzy neural networks as the intelligent controllers. This work has been motivated by a need to develop the solid control methodologies capable of coping with the complexity, the nonlinearity, the interactions, and the time variance of the processes under control. In addition, the dynamic behavior of such processes is strongly influenced by the disturbances and the noise, and such processes are characterized by a large degree of uncertainty. Therefore, it is important to integrate an intelligent component to increase the control system ability to extract the functional relationships from the process and to change such relationships to improve the control precision, that is, to display the learning and the reasoning abilities. The objective of this thesis was to develop a self-organizing learning controller for above processes by using a combination of the fuzzy logic and the neural networks. An on-line, direct fuzzy neural controller using the process input-output measurement data and the reference model with both structural and parameter tuning has been developed to fulfill the above objective. A number of practical issues were considered. This includes the dynamic construction of the controller in order to alleviate the bias/variance dilemma, the universal approximation property, and the requirements of the locality and the linearity in the parameters. Several important issues in the intelligent control were also considered such as the overall control scheme, the requirement of the persistency of excitation and the bounded learning rates of the controller for the overall closed loop stability. Other important issues considered in this thesis include the dependence of the generalization ability and the optimization methods on the data distribution, and the requirements for the on-line learning and the feedback structure of the controller. Fuzzy inference specific issues such as the influence of the choice of the defuzzification method, T-norm operator and the membership function on the overall performance of the controller were also discussed. In addition, the e-completeness requirement and the use of the fuzzy similarity measure were also investigated. Main emphasis of the thesis has been on the applications to the real-world problems such as the industrial process control. The applicability of the proposed method has been demonstrated through the empirical studies on several real-world control problems of industrial complexity. This includes the temperature and the number-average molecular weight control in the continuous stirred tank polymerization reactor, and the torsional vibration, the eccentricity, the hardness and the thickness control in the cold rolling mills. Compared to the traditional linear controllers and the dynamically constructed neural network, the proposed fuzzy neural controller shows the highest promise as an effective approach to such nonlinear multi-variable control problems with the strong influence of the disturbances and the noise on the dynamic process behavior. In addition, the applicability of the proposed method beyond the strictly control area has also been investigated, in particular to the data mining and the knowledge elicitation. When compared to the decision tree method and the pruned neural network method for the data mining, the proposed fuzzy neural network is able to achieve a comparable accuracy with a more compact set of rules. In addition, the performance of the proposed fuzzy neural network is much better for the classes with the low occurrences in the data set compared to the decision tree method. Thus, the proposed fuzzy neural network may be very useful in situations where the important information is contained in a small fraction of the available data.

Occupational health and safety management systems : system types and effectiveness

The aim of this thesis is to develop a framework to evaluate the relative performance of different types of health and safety management system. This objective is an analytical one, but it stems from a policy issue of public importance. Over the past decade Australia, like other countries, has seen the emergence and growth of interest in developing health and safety management systems. But are they all the same, and if not, do they differ in their effectiveness? The thesis does not seek to give a definitive answer to these questions. Given the novelty of the phenomenon and the lack of research on this subject, the research is exploratory. An hypothesis about the effectiveness of different health and safety management systems is developed rather than tested. The thesis proceeds by first defining health and safety management systems as a combination of the planning and review, the management arrangements, the consultative arrangements and the specific program elements that work together in an integrated way to improve health and safety performance. A research procedure is described involving twenty exploratory case studies. The thesis then - develops - from the literature and the case study research - an analytical framework to evaluate the performance of different health and safety management systems. That framework has two parts. First is a typology of health and safety management systems. This is constructed from two distinctions - between 'safe place' and 'safe person' approaches to health and safety; and between 'innovative' and traditional' management methods and structures. These distinctions yield four types of system. The typology was applied to the case studies which yielded a reasonable fit in most instances. The second part of the framework is a 'process evaluation' technique akin to Quality standards. Derived from the Victorian SafetyMAP audit criteria, the "e;process evaluation tool "e; is preferred to traditional outcome measures such as incident or claim rates. Using this measure, the twenty case study enterprises were classified as above average, average or below average in performance. These results correlated poorly with traditional incident trend and benchmark measures. The two elements of the framework are then combined to explore the relationship between the different types of system and their performance. Evidence from the twenty case studies showed a tendency for innovative/safe place firms to perform better than traditional/safe person firms. This finding can form the basis for a hypothesis that may be subject to statistical testing on a generalisable sample. In addition five 'best practice' cases were selected and subjected to a cross case analysis to search for common characteristics that might explain their performance. This analysis suggests the importance of a number of factors: senior managers who drive health and safety change and mobilise all possible resources in the pursuit of change; health and safety representatives who work with managers in a 'joint regulatory relationship' across system activities; the involvement of employees more generally, but not as a substitute for action by managers and health and safety representatives; a comprehensive approach to elimination of all hazards; and the introduction of innovative programs to continually improve systems and facilitate employee involvement in health and safety.

Composition effects on ion transport in a polyelectrolyte gel with the addition of ion dissociators

The polymerization of lithium 2-acrylamido-2-methyl-1-propane sulphonic acid with N,N′-dimethylacrylamide has yielded polyelectrolyte gels which have the favourable property of being single ion conductors. The use of single ion conductors ensures that the transport number of lithium is close to unity. The mobility of the lithium ion is still quite low in these systems, resulting in low ionic conductivity. To increase ionic conductivity more charge carriers can be added however competing effects arise between increasing the number of charge carriers and decreasing the mobility of these charge carriers. In this paper the monomer ratio of the copolymer polyelectrolyte is varied to investigate the effect increasing the number of charge carriers has on the ionic conductivity and lithium ion and solvent diffusivity using pfg-NMR. Ion dissociators such as TiO₂ nano-particles and a zwitterionic compound based on 1-butylimidazolium-3-(N-butanesulfonate) have been added in an attempt to further increase the ionic conductivity of the system. It was found that the system with the highest ionic conductivity had the lowest solvent mobility in the presence of zwitterion. Without zwitterion the mobility of the solvent appears to determine the maximum ionic conductivity achievable.

A multi-vector, multi-envelope HIV-1 vaccine

The St. Jude Children's Research Hospital (St. Jude) HIV-1 vaccine program is based on the observation that multiple, antigenically distinct HIV-1 envelope protein structures are capable of mediating HIV-1 infection. A cocktail vaccine comprising representatives of these diverse structures (immunotypes) is therefore considered necessary to elicit lymphocyte populations that prevent HIV-1 infection. This strategy is reminiscent of that used to design a currently licensed and successful 23-valent pneumococcus vaccine. Three recombinant vector systems are used for the delivery of envelope cocktails (DNA, vaccinia virus, and purified protein) and each of these has been tested individually in phase I safety trials. A fourth clinical trial, in which diverse envelopes and vectors are combined in a prime-boost vaccination regimen, has been FDA-approved and is expected to commence in 2007. This trial will continue to test the hypothesis that a multivector, multi-envelope vaccine can elicit diverse 8- and T-cell populations that can prevent HIV-1 infections in humans.

Market analysis study of the value technology systems to home owners

Smart Technology involves the integration of a variety of home systems including lighting, climate control, security etc. to enhance the comfort, convenience and economy of the home for its users. It is currently unknown if home buyers believe that these systems add value to the home. This study used the market value of home sales and an attitudinal survey of home buyers, to determine the increased value of homes containing Smart Technology. The results demonstrated that a significant price premium was paid by for the incorporation of the technology into new homes. In addition, the research suggests that the use of this technology is not limited to high income earners or other demographic stereotypes. Instead it has broad market appeal and the potential to save energy for the community at large.

Analysis of the value of home automation systems

Smart technology involves the integration of a variety of home systems including lighting, climate control, security etc. to enhance the comfort, convenience and economy of the home for its users. It is currently unknown if homebuyers believe that these systems add value to the home. This study used the market value of home sales and an attitudinal survey of homebuyers, to determine the increased value of homes containing smart technology. The results demonstrated that a significant price premium was paid for the incorporation of the technology into new homes. In addition, the research suggests that the use of this technology is not limited to high-income earners or other demographic stereotypes. Instead it has broad market appeal and the potential to save energy for the community at large.