State and input simultaneous estimation for a class of nonlinear systems

This paper addresses the problem of estimating simultaneously the state and input of a class of nonlinear systems. Here, the systems nonlinear part comprises a Lipschitz nonlinear function with respect to the state and input, and a state-dependent unknown function including additive disturbance as well as uncertain/nonlinear/time-varying terms. Upon satisfying some conditions, the observer design problem can be solved via a Riccati inequality or a LMI-based technique with asymptotic estimation guaranteed. A numerical example is included for illustration.

Crushing simulation of foam-filled aluminium tubes

A numerical study is presented in this paper to investigate the energy absorption of foam-filled aluminium tubes during crushing. The post-buckling mode of the foam-tube structures has been successfully simulated. The predicted compressive load-displacement is in a good agreement with experimental results. The energy absorption ability of the composite structure due to plastic deformation in a crushing process is evaluated by comparison with the tube structure without foam. The results indicate that the energy absorption of a foam-filled tube structure is superior to the tube without foam. The influences of the friction and the geometric parameters of the structure on the energy absorption have also been investigated. Results from this study will assist automotive industry to design crashworthy components based on foam-filled tubes.

Evolution of class I cytokine receptors

Background
The Class I cytokine receptors have a wide range of actions, including a major role in the development and function of immune and blood cells. However, the evolution of the genes encoding them remains poorly understood. To address this we have used bioinformatics to analyze the Class I receptor repertoire in sea squirt (Ciona intestinalis) and zebrafish (Danio rerio).
Results
Only two Class I receptors were identified in sea squirt, one with homology to the archetypal GP130 receptor, and the other with high conservation with the divergent orphan receptor CLF-3. In contrast, 36 Class I cytokine receptors were present in zebrafish, including representative members for each of the five structural groups found in mammals. This allowed the identification of 27 core receptors belonging to the last common ancestor of teleosts and mammals.
Conclusion
This study suggests that the majority of diversification of this receptor family occurred after the divergence of urochordates and vertebrates approximately 794 million years ago (MYA), but before the divergence of ray-finned from lobe-finned fishes around 476 MYA. Since then, only relatively limited lineage-specific diversification within the different Class I receptor structural groups has occurred.

State and input simultaneous estimation for a class of time-delay systems with uncertainties

This brief addresses the problem of estimation of both the states and the unknown inputs of a class of systems that are subject to a time-varying delay in their state variables, to an unknown input, and also to an additive uncertain, nonlinear disturbance. Conditions are derived for the solvability of the design matrices of a reduced-order observer for state and input estimation, and for the stability of its dynamics. To improve computational efficiency, a delay-dependent asymptotic stability condition is then developed using the linear matrix inequality formulation. A design procedure is proposed and illustrated by a numerical example.

Thats classified: class politics and adolescence in twin peaks

Twin Peaks arguably paved the way for the television programmes currently popular with adolescent audiences, like The OC and Veronica Mars and, in it, many of the issues and representational strategies in those later programmes have their earlier manifestation. Specifically, the Twin Peaks plotline evinces a set of cultural anxieties about class-difference. Twin Peaks creates a cultural microcosm of American society that is paradoxically writ large by the limited parameters of an isolated community. Within a constricted space, characters are depicted as both individuals and as archetypes of a class location.

Public finance and income redistribution in interwar Australia: towards a class analysis

In this paper I focus on a neglected aspect of Australian political history, the extent to which Australian governments actually redistributed income. The German sociologist Rudolf Goldscheid argued that 'the budget is the skeleton of the state stripped of all misleading ideologies'. In Australia a party that claimed to represent lower income earners, the Labor Party, was a major political force, but did Labor actually make a difference to the distribution of income across social classes, or did Labor's rhetoric of equity merely serve to incorporate workers into the capitalist system? A quantitative approach to the political history of labour may enable us to escape both nostalgia for old labourism (which the Howard years have encouraged) and a simple and undifferentiated rejection of labourism as a reformist agent of social integration.

This paper incorporates some material from a 2005 paper that examined overall expenditure patterns and taxation patterns across the states and Commonwealth from 1910 to 1940 but it goes beyond the aggregate approach of this paper to consider the extent which the varying patterns of taxation and public expenditure across Australia impacted on different social classes during the 1930s. It is very much a preliminary analysis based on existing compilations of taxation statistics. It is a static analysis and does not consider if nominally redistributive taxation and expenditure patterns might be rendered ineffective by consequent interstate migration.

syn-Facial hetero-bridged [n]polynorbornanes : a new class of polarofacial framework molecules composed of fused 7-oxa- and 7-azanorbornanes

New oxygen-bridged norbornane-fused cyclobutene epoxides and bis-(cyclobutene epoxides) are described and shown to react stereoselectively with 7-azanorbornenes to produce syn-facial N,O-bridged polynorbornanes and stereorandomly with 7-oxanorbornenes to produce O,O-bridged polynorbornanes as mixtures of syn-facial and anti-facial products.[1] Polarofacial systems containing up to six syn-facial norbornane bridges are described, while systems with seven co-facial oxygen atoms have been prepared by incorporating terminal epoxide rings to O5-[5]polynorbornanes. Ester-substituted 1,3,4-oxadiazoles are shown to be useful reagents for coupling 7-oxanorbornanes and produce predominantly syn-facial O-bridged polarofacial systems together with their anti-facial isomers.

Synthesis of [n]polynorbornanes with differing edge substitution: a new class of regioselectively addressable framework

Polynorbornanes with differing edge functionality have been synthesised from the appropriate cyclobutene epoxides substituted with two, unlike, electron withdrawing groups. These latter compounds were prepared by the monohydrolysis of symmetric cyclobutene diesters and subsequent elaboration of the resulting carboxylic acid.

"As long as it doesn't spill over into class": harms arising from students` alcohol use, and the role of policy in reducing them

While there is considerable evidence about the prevalence of student alcohol use, little empirical work has examined the range and level of exposure to alcohol-related risks facing student populations, and the views of key stakeholders about these. This study was conducted at a large multi-campus university in order to gauge the scale and severity of students’ alcohol-related problems, and ways in which these may be mitigated. Student perspectives on campus based policy making with respect to alcohol were also canvassed. This study utilised a range of evaluative instruments, including standardised questionnaire protocols, structured interviews and focus groups. Data gained from students showed a large level of exposure to alcohol-related harm, and staff informants reported student harms such as drink-driving, interpersonal aggression, social nuisance, inadequate security, sexually risky behaviour, and physical malaise. As a group, students seem receptive to campus-based policies that have a harm reduction focus, but are less supportive of institutionalised measures aimed at the student body. Given the divergence of views about the harms arising from student drinking, and a general repudiation of institutional policy measures which may lessen these, the development of harm-reducing policy on alcohol remains challenging.

Reliability and validity of physical activity questionnaires for children: the children's leisure activities study survey (CLASS)

Examines the development of a reliable, valid and feasible method for assessing physical activity among children ages 5-6 and 10-12 years. Information on the subjects of the study; Assessment of test-retest reliability of a parental proxy questionnaire and a children's self-report questionnaire; Utilization of accelerometry to assess the criterion validity of the questionnaire.

Energy absorption and crushing behaviour of foam-filled aluminium tubes

The crushing behaviour and energy absorption of foam filled aluminium tubular structures were investigated using the quasi-static compressive tests. The crushing behaviour of the tubular structures changed due to foam filling. The energy absorption of the foam filled tubular structures was improved significantly. Foam filling caused an interaction effect between the tube and the foam during progressive crushing, leading to an increase in the mean crushing load compared to that of the foam or tube itself. This interaction effect might be affected by several parameters such as the density of the foam, the properties of both the foam material and tube material, and the thickness and outer diameter of the tube. In particular, the interaction effect essentially depended on the ratio of the mean crushing force of the foam to that of the tube.