The generation of virtual prototypes for performance optimization

I am suspicious of tools without a purpose - tools that are not developed in response to a clearly defined problem. Of course tools without a purpose can still be useful. However the development of first generation CAD was seriously impeded because the solution came before the problem. We are in danger of repeating this mistake if we do not clarify the nature of the problem that we are trying to solve with the next generation of tools. Back in the 1980s I used to add a postscript slide at the end of CAD conference presentations and the applause would invariably turn to concern. The slide simple asked: can anyone remember what it was about design that needed aiding before we had computer aided design?

Asset specificity and behavioural uncertainty as moderators of the sales growth : employment growth relationship in emerging ventures

Sales growth and employment growth are the two most widely used growth indicators for new ventures; yet, sales growth and employment growth are not interchangeable measures of new venture growth. Rather, they are related, but somewhat independent constructs that respond differently to a variety of criteria. Most of the literature treats this as a methodological technicality. However, sales growth with or without accompanying employment growth has very different implications for managers and policy makers. A better understanding of what drives these different growth metrics has the potential to lead to better decision making. To improve that understanding we apply transaction cost economics reasoning to predict when sales growth will be or will not be accompanied by employment growth. Our results indicate that our predictions are borne out consistently in resource-constrained contexts but not in resource-munificent contexts.

Heavy truck suspension optimization based on modified skyhook damping control

This paper presents a multi-objective optimization strategy for heavy truck suspension systems based on modified skyhook damping (MSD) control, which improves ride comfort and road-friendliness simultaneously. A four-axle heavy truck-road coupling system model was established using functional virtual prototype technology; the model was then validated through a ride comfort test. As the mechanical properties and time lag of dampers were taken into account, MSD control of active and semi-active dampers was implemented using Matlab/Simulink. Through co-simulations with Adams and Matlab, the effects of passive, semi-active MSD control, and active MSD control were analyzed and compared; thus, control parameters which afforded the best integrated performance were chosen. Simulation results indicated that MSD control improves a truck’s ride comfort and roadfriendliness, while the semi-active MSD control damper obtains road-friendliness comparable to the active MSD control damper.

Constraints on the complete optimization of human motion

In sport and exercise biomechanics, forward dynamics analyses or simulations have frequently been used in attempts to establish optimal techniques for performance of a wide range of motor activities. However, the accuracy and validity of these simulations is largely dependent on the complexity of the mathematical model used to represent the neuromusculoskeletal system. It could be argued that complex mathematical models are superior to simple mathematical models as they enable basic mechanical insights to be made and individual-specific optimal movement solutions to be identified. Contrary to some claims in the literature, however, we suggest that it is currently not possible to identify the complete optimal solution for a given motor activity. For a complete optimization of human motion, dynamical systems theory implies that mathematical models must incorporate a much wider range of organismic, environmental and task constraints. These ideas encapsulate why sports medicine specialists need to adopt more individualized clinical assessment procedures in interpreting why performers' movement patterns may differ.

Biomechanical force displacement analysis of strength of fixation of tracker holding devices to bone in computer aided joint replacement

Computer aided joint replacement surgery has become very popular during recent years and is being done in increasing numbers all over the world. The accuracy of the system depends to a major extent, on accurate registration and immobility of the tracker attachment devices to the bone. This study was designed to asses the forces needed to displace the tracker attachment devices in the bone simulators. Bone simulators were used to maintain the uniformity of the bone structure during the study. The fixation devices tested were 3mm diameter self drilling, self tapping threaded pin, 4mm diameter self tapping cortical threaded pin, 5mm diameter self tapping cancellous threaded pin and a triplanar fixation device ‘ortholock’ used with three 3mm pins. All the devices were tested for pull out, translational and rotational forces in unicortical and bicortical fixation modes. Also tested was the normal bang strength and forces generated by leaning on the devices. The forces required to produce translation increased with the increasing diameter of the pins. These were 105N, 185N, and 225N for the unicortical fixations and 130N, 200N, 225N for the bicortical fixations for 3mm, 4mm and 5mm diameter pins respectively. The forces required to pull out the pins were 1475N, 1650N, 2050N for the unicortical, 1020N, 3044N and 3042N for the bicortical fixated 3mm, 4mm and 5mm diameter pins. The ortholock translational and pull out strength was tested to 900N and 920N respectively and still it did not fail. Rotatory forces required to displace the tracker on pins was to the magnitude of 30N before failure. The ortholock device had rotational forces applied up to 135N and still did not fail. The manual leaning forces and the sudden bang forces generated were of the magnitude of 210N and 150N respectively. The strength of the fixation pins increases with increasing diameter from three to five mm for the translational forces. There is no significant difference in pull out forces of four mm and five mm diameter pins though it is more that the three mm diameter pins. This is because of the failure of material at that stage rather than the fixation device. The rotatory forces required to displace the tracker are very small and much less that that can be produced by the surgeon or assistants in single pins. Although the ortholock device was tested to 135N in rotation without failing, one has to be very careful not to put any forces during the operation on the tracker devices to ensure the accuracy of the procedure.

Residential sales by auction : a property type or geographic consideration

The sale of residential property by auction is a preferred sale method by real estate agents, but not always preferred by some vendors and most residential property buyers. In many residential property markets, the performance and measure of residential property market activity is based on the number of properties offered for sale by auction, auction clearance rates and the number of properties sold prior to auction. However, in many specific residential property markets, sale by auction may not be the preferred or supported method of sale. This paper will review the type of residential property sale within the Sydney residential property market and track the auction sales and clearance rates for Sydney over the past 5 months and compare these results in relation to clearance rates, passed in sales, and properties sold prior to auction This will provide a breakdown of real estate agency sale practice over a large metropolitan region to determine the impact of geographic location and socio-economic factors on the auction of residential property. In addition the paper will analyse the weekly auction sales in the Sydney residential property market to determine what areas of Sydney have the greatest number of house auctions and the performance of the auctions in relation location and socio economic factors.

Real estate agency practice and profitability : an analysis of house sales and agency profitability in Sydney

Large cities provide a broad range of residential property types, as well as a range of socio-economic locations. This results in a significant variation in residential property prices across both the city itself and the individual suburbs. The only constant across such a diverse range of residential property is the need for the majority of residential property owners to employ the services of a real estate agent to sell their property or to purchase a residential property. This paper will analyse the Sydney residential property market over the period 1994 to 2002 to determine the change in real estate offices numbers over the period, the profitability of real estate agency offices based on the residential house price performance of houses and units in these specific locations and the extent of changing residential house prices on agency profitability. Suburbs have been selected to provide a full range of housing types, socio-economic areas, older established and developing residential suburbs and location from the

An analysis and comparison of rural land sales

Rural land prices, in developed, free trade real estate markets, are influenced not only by prevailing economic conditions but also physical factors such as climate, topography and soil type. In broad acre farming and grazing operations, both commodity price and yields determine farm income. Yields, in turn, are a function of climate, topography and soil type. The strength of a rural land market is influenced by the overall rural economy in a Country, State or region. These differences in rural land markets can also vary within smaller regions. It has been held that rural land, in relative safe production areas, is less effected by adverse economic and climatic factors than land in more marginal agricultural areas. This paper will analyse rural land sales in both traditional cropping areas and marginal cropping areas for the period 1975 to 1996. The analysis will determine the overall trend in rural land prices over the period, compare the average annual return between marginal and established farming areas and determine which economic and production factors have influenced this change. The impact of this analysis will also be discussed in relation to rural land appraisal.

(-)-CGP12177 increases contractile force through beta1l-adrenoceptors but not through beta3-adrenoceptors in human right atrial myocardium

(-)-CGP12177 is a non-conventional partial agonist that causes modest and transient increases of contractile force in human atrial trabeculae (Kaumann and Molenaar, 2008). These effects are markedly increased and maintained by inhibition of phosphodiesterase PDE3. As verified with recombinant receptors, the cardiostimulant effect of (-)-CGP12177 is mediated through a site at the beta1-adrenoceptor with lower affinity (beta1LAR) compared to the site through which (-)-CGP12177 antagonizes the effects of catecholamines (beta1HAR). However, in a recent report it was proposed that the positive inotropic effects of CGP12177 are mediated through beta3-adrenoceptors (Skeberdis et al 2008). We therefore investigated whether the effects of (-)-CGP12177 on human atrial trabeculae are antagonized by the beta3-adrenoceptor-selective antagonist L-748,337 (1 microM). (-)-CGP12177 (200 nM) caused a stable increase in force which was significantly reduced by the addition of (-)-bupranolol (1 microM), P = 0.002, (basal 4.45 ± 0.78 mN, IBMX (PDE inhibitor) 5.47 ± 1.01 mN, (-)-CGP12177 9.34 ± 1.33 mN, (-)-bupranolol 5.79 ± 1.08 mN, n = 6) but not affected by the addition of L-748,337 (1 microM), P = 0.12, (basal 4.48 ± 1.32 mN, IBMX 7.15 ± 2.28 mN, (-)-CGP12177 12.51 ± 3.71 mN, L-748,337 10.90 ± 3.49 mN, n = 6). Cumulative concentration-effect curves for (-)-CGP12177 were not shifted to the right by L-748,337 (1 microM). The –logEC50M values of (-)-CGP12177 in the absence and presence of L-748,337 were 7.21±0.09 and 7.41±0.13, respectively (data from 25 trabeculae from 8 patients, P=0.2) The positive inotropic effects of (-)-CGP12177 (IBMX present) were not antagonized by L-748,337 but were blunted by (-)-bupranolol (1 microM). The results rule out an involvement of beta3-adrenoceptors in the positive inotropic effects (-)-CGP12177 in human right atrial myocardium and are consistent with mediation through beta1LAR. Kaumann A and Molenaar P (2008) Pharmacol Ther 118, 303-336 Skeberdis VA et al (2008) J Clin Invest, 118, 3219-3227

A cost-based optimization of a fiberboard pressing plant using Monte-Carlo simulation (a reliability program)

In this research the reliability and availability of fiberboard pressing plant is assessed and a cost-based optimization of the system using the Monte- Carlo simulation method is performed. The woodchip and pulp or engineered wood industry in Australia and around the world is a lucrative industry. One such industry is hardboard. The pressing system is the main system, as it converts the wet pulp to fiberboard. The assessment identified the pressing system has the highest downtime throughout the plant plus it represents the bottleneck in the process. A survey in the late nineties revealed there are over one thousand plants around the world, with the pressing system being a common system among these plants. No work has been done to assess or estimate the reliability of such a pressing system; therefore this assessment can be used for assessing any plant of this type.

The well-being of older job-seekers : implications for the labour force participation agenda

Throughout the developed world demographic trends and their forecast consequences are attracting the attention of governments, academics, think tanks and the popular press alike. Population aging, in particular, is the focus of many and has generated extensive debate. Approaches commonly advocated in the literature include a mix of ‘population', ‘participation’ and ‘productivity’ measures. Immigration and population policy alongside industry reform and related productivity initiatives are also being pursued. Participation, however, remains a key element of the demographic change policy response. Evidence suggests however, that these approaches are unlikely to deliver the necessary labour force volumes. This has prompted a shift in the participation agenda to also include a stronger focus on skilled and experienced older workers. The literature suggests, however, that the current suite of practices are less than effective for the long-term unemployed, previously long-tenured older workers with specialised skills and trade-displaced workers. Adverse health and human capital outcomes often associated with social disadvantage are complicating factors. This reminds of the complexity of the challenge in seeking to deliver social equity to the disadvantaged and suggests a need for an alternative policy architecture. By integrating the three concepts of health capital, human capital and social capital we show how policy has to change if the older age cohorts of jobseekers are to be assisted to remain employable. This review includes an examination of current policy, a consolidation of the literature and original data.

Aging and the force-velocity relationship of muscles

Aging in humans is associated with a loss in neuromuscular function and performance. This is related, in part, to the reduction in muscular strength and power caused by a loss of skeletal muscle mass (sarcopenia) and changes in muscle architecture. Due to these changes, the force-velocity (f-v) relationship of human muscles alters with age. This change has functional implications such as slower walking speeds. Different methods to reverse these changes have been investigated, including traditional resistance training, power training and eccentric (or eccentrically-biased) resistance training. This review will summarise the changes of the f-v relationship with age, the functional implications of these changes and the various methods to reverse or at least partly ameliorate these changes.

Behavioural biases and information disclosure laws relating to residential property sales : narrowing the gap between existing laws and calls for future reforms

Market failures involving the sale of complex merchandise, such as residential property, financial products and credit, have principally been attributed to information asymmetries. Existing legislative and regulatory responses were developed having regard to consumer protection policies based on traditional economic theories that focus on the notion of the ‘rational consumer’. Governmental responses therefore seek to impose disclosure obligations on sellers of complex goods or products to ensure that consumers have sufficient information upon which to make a decision. Emergent research, based on behavioural economics, challenges traditional ideas and instead focuses on the actual behaviour of consumers. This approach suggests that consumers as a whole do not necessarily benefit from mandatory disclosure because some, if not most, consumers do not pay attention to the disclosed information before they make a decision to purchase. The need for consumer policies to take consumer characteristics and behaviour into account is being increasingly recognised by governments, and most recently in the policy framework suggested by the Australian Productivity Commission