Univariate and multivariate process yield indices based on location-scale family of distributions

Several measures of process yield, defined on univariate and multivariate normal process characteristics, have been introduced and studied by several authors. These measures supplement several well-known Process Capacity Indices (PCI) used widely in assessing the quality of products before being released into the marketplace. In this paper, we generalise these yield indices to the location-scale family of distributions which includes the normal distribution as one of its member. One of the key contributions of this paper is to demonstrate that under appropriate conditions, these indices converge in distribution to a normal distribution. Several numerical examples will be used to illustrate our procedures and show how they can be applied to perform statistical inferences on process capability.

Can indices of ecological evenness be used to measure consensus?

In the context of group decision making with fuzzy preferences, consensus measures are employed to provide feedback and help guide automatic or semi-automatic decision reaching processes. These measures attempt to capture the intuitive notion of how much inputs, individuals or groups agree with one another. Meanwhile, in ecological studies there has been an ongoing research effort to define measures of community evenness based on how evenly the proportional abundances of species are distributed. The question hence arises as to whether there can be any cross-fertilization from developments in these fields given their intuitive similarity. Here we investigate some of the models used in ecology toward their potential use in measuring consensus. We found that although many consensus characteristics are exhibited by evenness indices, lack of reciprocity and a tendency towards a minimum when a single input is non-zero would make them undesirable for inputs expressed on an interval scale. On the other hand, we note that some of the general frameworks could still be useful for other types of inputs like ranking profiles and that in the opposite direction consensus measures have the potential to provide new insights in ecology.

Indices for cashmere fleece competition and across farm comparisons: The role of staple length in identifying goats of higher cashmere production

A single focus on mean fibre diameter (MFD, μm) as the definition of cashmere quality overlooks the effects of fibre length, softness and fibre curvature on cashmere processing, textile quality and consumer acceptance. Many farmers overlook the importance of cashmere staple length (SL, cm) in their fleece assessments. We aimed to determine the importance of SL in comparison with MFD when evaluating cashmere production and to identify how across farm comparisons of cashmere fleeces can be objectively undertaken. A sample of 1244 commercial cashmere fleeces from goats originating from many Australian farms was used. Least squares models, relating the logarithm of clean cashmere production (CCMwt, g) to MFD and SL, were fitted. Six years of data from the Australian cashmere industry between farm fleece competitions were analysed to determine the relation between CCMwt and MFD. In the research flocks, adjusting CCMwt of individual goats across farms for MFD only accounted for 2% of the variance, whereas SL accounted for 39% of the variance. The least squares additive model involving only SL was: log10(CCMwt)=1.570+0.06010×SL. Thus CCMwt was proportional to: 100.06010×SL=1.1484SL. It was appropriate to adjust CCMwt for SL by a factor 1/1.1484(SL-SL0) where SL0 is a standard SL of 7.5cm. The between farm index for cashmere weight equals: cleancashmerestaplelengthindex=2.823×CCMwt/1.1484SL. For industry fleece competitions, regression analysis indicated that there was no association between cashmere production and MFD (P=0.81), similar to the research data. Adjusting CCMwt for MFD in across farm comparison and fleece competitions appears to be ineffective. For farm comparisons and in fleece competitions it is important to assess cashmere SL. The use of the Clean Cashmere Staple Length Index will provide a more robust comparison of cashmere productivity between farms as it is an indirect indicator of desirable skin secondary follicle development. The results have application in development projects where obtaining a cashmere MFD test is costly or unavailable. © 2013 Elsevier B.V.

Undercarboxylated osteocalcin, muscle strength and indices of bone health in older women

We investigated the association between undercarboxylated osteocalcin (ucOC) and lower-limb muscle strength in women over the age of 70years. The study also aims to confirm the association between bone turnover markers and heel ultrasound measures. A post-hoc analysis using data collected as part of a randomized placebo-controlled trial of vitamin D supplementation. An immunoassay was used to quantify total OC (tOC), with hydroxyapatite pre-treatment for ucOC. We determined associations of absolute and relative (ucOC/tOC; ucOC%) measures of ucOC with lower-limb muscle strength, heel ultrasound measures of speed of sound (SOS) and broadband ultrasound attenuation (BUA), bone turnover markers (BTMs; P1NP and CTx) and the acute phase protein alpha-1-antichymotrypsin (α-ACT). ucOC%, but not absolute ucOC concentration, was positively associated with hip flexor, hip abductor and quadriceps muscle strength (all p<0.05). ucOC% was negatively associated with α-ACT (β-coefficient=-0.24, p=0.02). tOC was positively associated with both P1NP and CTx (p<0.001). For each per unit increase in tOC (μg/L) there was a corresponding lower BUA, SOS and SI (β-coefficient = -0.28; -0.23 and -0.23, respectively; all p<0.04). In conclusion, ucOC% is positively associated with muscle strength and negatively associated with α-ACT. These data support a role for ucOC in musculoskeletal interactions in humans. Whilst tOC is associated with bone health, ucOC% and ucOC may also be linked to falls and fracture risk by influencing muscle function.

All signals are not equal: acoustic signalling of individuality, sex and breeding status in a cooperative breeder

Repeated interactions between individuals in socially living animals select for the evolution of signals that convey information identifying individuals or categories of individuals, which may enable the discrimination of familiar versus unfamiliar individuals. Such information may help animals maximize their inclusive fitness by adjusting their own behaviour, allowing them to avoid conflict, preferentially direct help and/or ignore unreliable individuals. Acoustic signals in birds provide the potential to encode individual-specific information. We examined the degree to which individual identity, sex, breeding status, group membership and genetic relatedness were related to variability in six different call types, which occurred across a variety of different behavioural contexts in the apostlebird, Struthidea cinerea, a socially living and cooperatively breeding Australian passerine. We demonstrated that not all calls reflected the same extent of information. Of the six call types, call variation was related to individual identity in three call types, breeding status in two call types and sex and group relatedness in one call type. Finally, variation in two call types was not related to any of the measured variables. Our results suggest that some, but not all, acoustic signals in apostlebirds may be selected for individual distinctiveness between individuals and categories of individuals (male versus female, breeder versus nonbreeder), and these signals may be important in determining levels of cooperation and interaction between individuals in this cooperatively breeding society. © 2014 The Association for the Study of Animal Behaviour.

Investigation of hydraulic fracture propagation using a post-peak control system coupled with acoustic emission

This study investigates the fracture mechanism of fluid coupled with a solid resulting from hydraulic fracture. A new loading machine was designed to improve upon conventional laboratory hydraulic fracture testing and to provide a means of better understanding fracture behavior of solid media. Test specimens were made of cement mortar. An extensometer and acoustic emission (AE) monitoring system recorded the circumferential deformation and crack growth location/number during the test. To control the crack growth at the post-peak stage the input fluid rate can be adjusted automatically according to feedback from the extensometer. The complete stress-deformation curve, including pre- and post-peak stages, was therefore obtained. The crack extension/growth developed intensively after the applied stress reached the breakdown pressure. The number of cracks recorded by the AE monitoring system was in good agreement with the amount of deformation (expansion) recorded by the extensometer. The results obtained in this paper provide a better understanding of the hydraulic fracture mechanism which is useful for underground injection projects. © 2014 Springer-Verlag Wien.

Indices for the identification of biologically productive cashmere goats within farms

Objectively comparing cashmere goats with different cashmere production, mean fibre diameter (MFD) and staple length (SL) is difficult for farmers. We aimed to develop indices to enable cashmere producers to identify productive goats within their own farms once adjustments had been made for the primary determinants of cashmere production. That is we aimed to develop indices that identify goats and herds that biologically have a high fleece weight in relation to MFD and SL. We used a sample of 1244 commercial cashmere fleeces from goats originating from many Australian farms based in different environmental zones and a previously developed general linear model that related the logarithm of clean cashmere production (CCMwt) and any other potential determinant. In the present study, sub-models were investigated in order to develop new indices for comparing goats in the same farm, based on fleece characteristics and biological efficiency. New Index (MFD), equal to 6.02×CCMwt/1.1531^MFD, was developed to identify animals of biologically high CCMwt in relation to their MFD. Unlike previously reported results that MFD is not a useful measurement for comparing the biological efficiency of cashmere goats across farms, the New Index (MFD) allows comparison of the biological efficiency of cashmere goats within farms. New Index (SL), equal to 2.70 × CCMwt/1.1414^SL, was developed to identify animals of biologically high CCMwt in relation to their SL. New Index (SL) is very similar to the Clean Cashmere Staple Length Index (CCSLI) that had been previously reported for comparison of cashmere goats across farms, and thus the CCSLI can be usefully used for comparing the biological efficiency of cashmere goats both across and within farms. New Index MFD, SL = 8.90 × CCMwt/1.243^(MFD+SL)/2 was developed to identify animals of biologically high CCMwt in relation to both their MFD and SL within farms, and provides useful information above using either New Index (MFD) or CCSLI. The indices can be presented in the same measurement units as fleece weight, which is a biological concept easily understood by cashmere producers, and enable comparisons to be made between animals using just one attribute, clean cashmere weight.

The relative importance of spatial proximity, kin selection and potential ‘greenbeard’ signals on provisioning behaviour among helpers in a cooperative bird

© 2015 Springer-Verlag Berlin Heidelberg Many hypotheses have been proposed to account for cooperative behaviour, with those favouring kin selection receiving the greatest support to date. However, the importance of relatedness becomes less clear in complex societies where interactions can involve both kin and non-kin. To help clarify this, we examined the relative effect of indirect versus key direct benefit hypotheses in shaping cooperative decisions. We assessed the relative importance of likely reciprocal aid (as measured by spatial proximity between participants), kin selection (using molecular-based relatedness indices) and putative signals of relatedness (vocal similarity) on helper/helper cooperative provisioning dynamics in bell miners (Manorina melanophrys), a species living in large, complex societies. Using network analysis, we quantified the extent of shared provisioning (helping at the same nests) among individual helpers (excluding breeding pairs) over three seasons and 4290 provisioning visits, and compared these with the location of individuals within a colony and networks built using either genetic molecular relatedness or call similarity indices. Significant levels of clustering were observed in networks; individuals within a cluster were more closely related to each other than other colony members, and cluster membership was stable across years. The probability of a miner helping at another’s nest was not simply a product of spatial proximity and thus the potential for reciprocal aid. Networks constructed using helping data were significantly correlated to those built using molecular data in 5 of 10 comparisons, compared to 8 of 10 comparisons for networks constructed using call similarity. This suggests an important role of kinship in shaping helping dynamics in a complex cooperative society, apparently determined via an acoustic ‘greenbeard’ signal in this system.