Using geometric shape variations to create an inverse model for a sheet metal process

The output of the sheet metal forming process is subject to much variation. This paper develops a method to measure shape variation in channel forming and relate this back to the corresponding process parameter levels of the manufacturing set-up to create an inverse model. The shape variation in the channels is measured using a modified form of the point distribution model (also known as the active shape model). This means that channels can be represented by a weighting vector of minimal linear dimension that contains all the shape variation information from the average formed channel.

The inverse models were created using classifiers that related the weighting vectors to the process parameter levels for the blank holder force (BHF), die radii (DR) and tool gap (TG) of the parameters. Several classifiers were tested: linear, quadratic Gaussian and artificial neural networks. The quadratic Gaussian classifiers were the most accurate and the most consistent type of classifier over all the parameters.

Are age-related variations in breeding performance greatest when food availability is limited?

Age-related improvements in reproductive performance in seabirds have been well documented, and may be explained by improvements in foraging efficiency or increased experience and reproductive effort with age. The interactive effects of parental age and food supply on reproductive performance, however, remain poorly understood. A widespread mass mortality of pilchards Sardinops sagax in southern Australian waters in 1998 provided a unique opportunity to investigate the effects of a sudden reduction in the availability of amajor prey species on Australasian gannets Morus serrator, an important local marine predator. Age-related differences in the breeding performance of gannets were evident in 1 year of reduced pilchard availability; when food was not limited, both young and experienced parents were equally capable of rearing chicks and had similar levels of breeding success. These data clearly demonstrate the interactive effects of parental age and food supply on breeding performance and suggest that such differences only become apparent when conditions become more stressful.

Can the use of foreign currency derivatives explain variations in foreign exchange exposure? Evidence from Australian companies

We investigate the role of foreign currency derivatives (FCD) in alleviating foreign exchange rate exposure of Australian firms. While there is some evidence that the use of FCD reduces the level of ex-post short-term exposure, such an effect is absent with regard to the degree of foreign operations. Our results support the view that FCDs are used to hedge existing exchange rate exposures and that Australian firms, generally, are extensively exposed to currency fluctuations in the long run. While monthly exposure appears to be a function of a firm's size and financial hedging, exchange rate exposure of shorter horizons (1 and 3 months) appears to be negatively related to a firm's price earnings ratio (proxying growth opportunities)—thereby supporting the ‘underinvestment’ hypothesis. Further, the exposure of longer horizons (12 and 24 months) is positively related to a firm's liquidity, supporting the view that liquidity is a substitute for hedging.

Operational experiences with rockbed storage systems

Many rockbed thermal storage systems were installed in solar homes and greenhouses in Australia during the 1970s and 1980s. However, this technology appears to have waned in popularity since that time, although other storage options such as phase change materials are still not established alternatives. This paper re-evaluates rockbed storage technology, in the light of the experiences of users over the last 20 years. Of the 31 systems investigated, only seven were determined to be still working. There are a number of reasons for this, depending on the type and use of the system, which are discussed.

Critical operational management in international construction

The construction activities of a contractor may physically take place in the home country or overseas, and the latter, particularly of a large company, has an increasing proportion with the globalisation. Globalisation of the construction industry and its market is a trend in every country, Which increases the opportunities of both international construction, and competition or collaboration with foreign construction companies. International construction project management is undertaken in a complicated circumstance, and requires a synthetic management approach. This research aims to establish a primary framework for the critical operational management in achieving international construction projects in a novel construction market.

The conceptualisation of operational risk management models

Operational risk is evolving as a specialist field of risk management that must be practiced within all organisations, but currently has a particular relevance to banks. The Basel Committee on Banking Supervision has circulated a consultative paper which, if adopted by nation-state bank supervisors, will impose an operational risk capital charge on banks as part of a new Capital Accord. The definition of operational risk is wide-ranging and creates some unique issues related to the development of appropriate risk management models. This paper conceptualises two distinct operational risk management models; being a predictive model that will result in a known outcome upon its implementation, and a pre-emptive operational risk management model which prepares an organisation in the event that a future risk occurrence results in a disruption to critical business operations.

Impetus to explore: approaching operational deficiency optimistically

‘Impetus to explore’ is studied through post-lesson video-stimulated student interviews. This impetus focuses ‘spontaneous’ decisions to explore unfamiliar mathematics. Uncertainty, quests for elegance and curiosity have been found to contribute to this impetus. This study identified other contributing factors: inability to undertake the teacher’s task, ‘optimistic explanatory style’ (Seligman, 1995), and identifying relevant complexities (Williams, 2002). Explanatory style affects how a person perceives successes and failures. Enactment of optimism in this study illuminated its role in creating an impetus to explore. Re-conceptualising ‘operational deficiency’ (Chen & Siegler, 2000) to include absence of resources to undertake a task illuminated a task design feature that can increase exploration.

Brand orientation: another explanation of retailer performance

This paper postulates that organisational capabilities, particularly brand orientation, may provide an appropriate theoretical framework to explain variations in organisational performance among retailers. Brand orientation is viewed as a strategic capability, just like innovation. This allows for a distinction to be made with such core antecedent (However, it is important to distinguish between strategic capabilities (innovation orientation and brand orientation) and antecedent core) capabilities such as market orientation, operational orientation and human resource orientation which all organizations must have to some degree. This distinction is made to emphasise that all organisations operate with some degree of market, operational and human resource orientation, whereas organisations can choose to operate without either innovation or brand orientation. We argue that it is the inclusion of organisational capabilities with positional advantage and organisational performance that provides an holistic conceptual framework for the empirical investigation we are currently undertaking. The propositions discussed in this paper link the various relationships in the conceptual model within the context of Australian retailing organisations.

Regional variations in walking for different purposes : the south east Queensland quality of life study

Where people are located can influence behavioral choices and health outcomes through the effects of place on health. Walking is the most commonly reported form of nonoccupational and nonhousehold physical activity for adults. It is a behavior of particular interest to those in the transportation, urban planning, and public health fields. Researchers have examined patterns of walking from both an individual perspective (psychological and social factors) and from a broader community focus (location and built environment factors). The majority of studies have examined walking in the context of urban environments. Variations within regions (urban, periurban, and rural, for example) in walking have not been previously described. We use data from a regionally based quality of life survey to examine subregional variations in walking for particular purposes. Both the social and contextual variations that may underlie these differences are considered. This is useful in helping identify particular factors that may be further investigated in disaggregated analyses using GIS methods to identify specific differences in objective attributes between subregions that may influence peoples' choices to walk, such as walking infrastructure and the availability of destinations.

Seasonal variations of lipid content and composition in perna viridis

The total lipid content, composition of main lipid classes, composition of sterols and composition of fatty acids in the main glycerolipids of Perna viridis were analyzed through four seasons using TLC-FID and GLC. Mussel samples were collected during different seasons between 2003 and 2004 from Shengsi Island, Zhejiang Province, China and stored frozen prior to freeze-drying and lipid extraction. Ten grams of dried mussel powder of each season were analyzed. Total lipid content ranged from 14.5 g/100 g in spring month to 7.8 g/100 g dried mussel powder in autumn month. The predominant lipid in spring month was triacylglycerol (TAG), however, in the other three seasons the phospholipids (PL) was the main lipid class. The most abundant fatty acid in TAG, PL and phosphatidylcholine (PC) was 16:0, with the summer samples having the highest proportion (24-30% of total fatty acid) and winter the lowest (14-22%). In phosphatidylethanolamine (PE), the spring samples had the highest proportions of 16:0. The predominant polyunsaturated fatty acids (PUFA) were 22:6n-3 and 20:5n-3 in TAG, PL, PE and PC (25-40%). The proportions of 22:6n-3 and 20:5n-3 were higher in spring than in other seasons in PL and PE. There were nine sterols identified, with cholesterol being the predominant sterol, and other main ones were desmostersol/brassicasterol and 24-methylenecholesterol. Proportions of other fatty acids in different lipid fractions and the sterol compositions as well also varied seasonally. There were subject to the seasonal variations. Differences in lipid content and composition, fatty acid composition in different lipid fractions may be caused by multiple factors such as lifecycle, sex, variation of plankton in different seasons and temperature, which could influence physiological activities and metabolism.

Diameter variations of irregular fibers under different tensions

The cross-section area of animal fibers varies along the fiber length, and this geometrical irregularity has a major impact on the mechanical properties of those fibers. In practice fibers are often subjected to tensile stresses during processing and application, which may change fiber cross-section area. It is thus necessary to examine geometrical irregularity of fibers under tension. In this study, scoured animal fibers were subjected to different tensile loading using a Single Fiber Analyzer (SIFAN) instrument. The 3D images of the fiber specimens were first constructed, and then along-fiber diameter irregularities of the specimens were analyzed for different levels of tensile loading. The changes in effective fineness of the fiber specimens were also discussed. The results indicate that for the wool fibers examined, there is considerable discrepancy in the fiber diameter results obtained from the commonly used single scan along fiber length and that from multiple scans at different rotational angles, and that the diameter variation along fiber length increases as fiber tension increases. The results also show that when diameter reduction treatments are applied to wool by stretching, the reduced average fiber diameter is associated with an increase in both within-fiber and between-fiber diameter variations. So in terms of effective fineness, the change is much smaller than the difference between the average diameters of the parent and treated wool. These results have significant implications for improving the accuracy of fiber diameter measurement and evaluation.