Arc voltage behavior in GMAW-P under different drop transfer modes

Purpose: Experimental measurements have been made to investigate meaning of the change in voltage for the pulse gas metal arc welding (GMAW-P) process operating under different drop transfer modes. Design/methodology/approach: Welding experiments with different values of pulsing parameter and simultaneous recording of high speed camera pictures and welding signals (such as current and voltage) were used to identify different drop transfer modes in GMAW-P. The investigation is based on the synchronization of welding signals and high speed camera to study the behaviour of voltage signal under different drop transfer modes. Findings: The results reveal that the welding arc is significantly affected by the molten droplet detachment. In fact, results indicate that sudden increase and drop in voltage just before and after the drop detachment can be used to characterize the voltage behaviour of different drop transfer mode in GMAW-P. Research limitations/implications: The results show that voltage signal carry rich information about different drop transfer occurring in GMAW-P. Hence it’s possible to detect different drop transfer modes. Future work should concentrate on development of filters for detection of different drop transfer modes. Originality/value: Determination of drop transfer mode with GMAW-P is crucial for the appropriate selection of pulse welding parameters. As change in drop transfer mode results in poor weld quality in GMAW-P, so in order to estimate the working parameters and ensure stable GMAW-P understanding the voltage behaviour of different drop transfer modes in GMAW-P will be useful. However, in case of GMAW-P hardly any attempt is made to analyse the behaviour of voltage signal for different drop transfer modes. This paper analyses the voltage signal behaviour of different drop transfer modes for GMAW-P.

Enhancing school connectedness to prevent violence and promote wellbeing

School connectedness is “the extent to which students feel personally accepted, respected, included, and supported by others in the school social environment” (Goodenow, 1993, p. 80). It is an important predictor of school violence, as well as related outcomes such as health risk behaviors and mental health. Connectedness reduces initial incidents of violence, buffers the effect of violence exposure, and promotes an anti-bullying culture. School violence and bullying have also been associated with a subsequent decrease in school connectedness. Several theories contribute to our understanding of these relations but the construct, theoretical underpinnings, and pathways in and out of school connectedness require further examination. Despite numerous promising interventions, this line of research is in its infancy. Interventions harnessing this protective factor may have a ubiquitous positive impact on adolescent development.

Research process management

Though the value of a process-centred view for the understanding and (re-)design of corporations has been widely accepted, our understanding of the research process in Information Systems (IS) remains superficial. A process-centred view on IS research considers the conduct of a research project as a sequence of activities involving resources, data and research artifacts. As such, it helps to reflect on more effective ways to conduct IS research, to consolidate and compare diverse practices and to complement the focus on research methodologies with research project practices. This paper takes a first step towards the discipline of ‘Research Process Management’ by exploring the features of research processes and by presenting a preliminary approach for research process design that can facilitate modelling IS research. The case study method and the design science research method are used as examples to demonstrate the potential of such reference research process models.

Diversified service provisioning in global business networks

Companies and their services are being increasingly exposed to global business networks and Internet-based ondemand services. Much of the focus is on flexible orchestration and consumption of services, beyond ownership and operational boundaries of services. However, ways in which third-parties in the “global village” can seamlessly self-create new offers out of existing services remains open. This paper proposes a framework for service provisioning in global business networks that allows an open-ended set of techniques for extending services through a rich, multi-tooling environment. The Service Provisioning Management Framework, as such, supports different modeling techniques, through supportive tools, allowing different parts of services to be integrated into new contexts. Integration of service user interfaces, business processes, operational interfaces and business object are supported. The integration specifications that arise from service extensions are uniformly reflected through a kernel technique, the Service Integration Technique. Thus, the framework preserves coherence of service provisioning tasks without constraining the modeling techniques needed for extending different aspects of services.

Review: "Information and Communication Technologies in Tourism 2003" edited by Frew, A.J., Hitz, M., & O’Connor, P.

"This volume represents the proceedings of the 10th ENTER conference, held in Helsinki, Finland during January 2003. The conference theme was ‘technology on the move’, and the 476pp. proceedings offer 50 papers by 108 authors. The editors advise all papers were subject to a double blind peer review. The research has been categorised into 18 broad headings, which reflects the diversity of topics addressed. This reviewer has adopted the approach of succinctly summarising each of the papers, in the order they appear, to assist readers of Tourism Management in judging the potential value of the content for their own work..." -- publisher website

Exploring the contested role of mandatory reporting laws in the identification of severe child abuse and neglect

Significant numbers of children are severely abused and neglected by parents and caregivers. Infants and very young children are the most vulnerable and are unable to seek help. To identify these situations and enable child protection and the provision of appropriate assistance, many jurisdictions have enacted ‘mandatory reporting laws’ requiring designated professionals such as doctors, nurses, police and teachers to report suspected cases of severe child abuse and neglect. Other jurisdictions have not adopted this legislative approach, at least partly motivated by a concern that the laws produce dramatic increases in unwarranted reports, which, it is argued, lead to investigations which infringe on people’s privacy, cause trauma to innocent parents and families, and divert scarce government resources from deserving cases. The primary purpose of this paper is to explore the extent to which opposition to mandatory reporting laws is valid based on the claim that the laws produce ‘overreporting’. The first part of this paper revisits the original mandatory reporting laws, discusses their development into various current forms, explains their relationship with policy and common law reporting obligations, and situates them in the context of their place in modern child protection systems. This part of the paper shows that in general, contemporary reporting laws have expanded far beyond their original conceptualisation, but that there is also now a deeper understanding of the nature, incidence, timing and effects of different types of severe maltreatment, an awareness that the real incidence of maltreatment is far higher than that officially recorded, and that there is strong evidence showing the majority of identified cases of severe maltreatment are the result of reports by mandated reporters. The second part of this paper discusses the apparent effect of mandatory reporting laws on ‘overreporting’ by referring to Australian government data about reporting patterns and outcomes, with a particular focus on New South Wales. It will be seen that raw descriptive data about report numbers and outcomes appear to show that reporting laws produce both desirable consequences (identification of severe cases) and problematic consequences (increased numbers of unsubstantiated reports). Yet, to explore the extent to which the data supports the overreporting claim, and because numbers of unsubstantiated reports alone cannot demonstrate overreporting, this part of the paper asks further questions of the data. Who makes reports, about which maltreatment types, and what are the outcomes of those reports? What is the nature of these reports; for example, to what extent are multiple numbers of reports made about the same child? What meaning can be attached to an ‘unsubstantiated’ report, and can such reports be used to show flaws in reporting effectiveness and problems in reporting laws? It will be suggested that available evidence from Australia is not sufficiently detailed or strong to demonstrate the overreporting claim. However, it is also apparent that, whether adopting an approach based on public health and or other principles, much better evidence about reporting needs to be collected and analyzed. As well, more nuanced research needs to be conducted to identify what can reasonably be said to constitute ‘overreports’, and efforts must be made to minimize unsatisfactory reporting practice, informed by the relevant jurisdiction’s context and aims. It is also concluded that, depending on the jurisdiction, the available data may provide useful indicators of positive, negative and unanticipated effects of specific components of the laws, and of the strengths, weaknesses and needs of the child protection system.

A software framework for risk-aware business process management

With the large diffusion of Business Process Managemen (BPM) automation suites, the possibility of managing process-related risks arises. This paper introduces an innovative framework for process-related risk management and describes a working implementation realized by extending the YAWL system. The framework covers three aspects of risk management: risk monitoring, risk prevention, and risk mitigation. Risk monitoring functionality is provided using a sensor-based architecture, where sensors are defined at design time and used at run-time for monitoring purposes. Risk prevention functionality is provided in the form of suggestions about what should be executed, by who, and how, through the use of decision trees. Finally, risk mitigation functionality is provided as a sequence of remedial actions (e.g. reallocating, skipping, rolling back of a work item) that should be executed to restore the process to a normal situation.

Seeing a hard country : Lawrence’s Australian landscape

In 1944 Australian author Eleanor Dark wrote that Australia is a hard country for an outsider to see, citing, in evidence, the writing of the “strange, foreign-looking little man with the beard” -- the self-described by D. H. Lawrence. According to Dark, Lawrence was bewildered by Australia because what his eyes saw was not what they were accustomed to seeing. Kangaroo, she wrote, suggests one long, tormented effort to see. Lawrence appears, for Dark, to be half-blind, struggling, and irritated almost beyond belief with his visit to New South Wales. Eleanor Dark wrote this critique in 1944, long after Lawrence’s 1922 visit, but for her, as for other Australian writers, Kangaroo continued to register as an important book, even if the content rankled. Katharine Susannah Prichard and Christina Stead, both advocates in general of Lawrence, likewise rejected the tenor of Kangaroo, although Lawrence would not have been worried about the response. In 1929 he referred to his irritation with Australia in letters to P.R. “Inky” Stephensen, the Australian nationalist and publisher, and he does not seem to have changed his opinions since writing Kangaroo. Yet the novel continued to be significant for Australian writers, even if as a provocation. My discussion traces the responses of the women authors to Kangaroo, and refers to Lawrence’s letters to Stephensen, as a way of emphasizing this significance, seen especially in relation to ideas about ‘seeing’ and the Australian landscape.

Tear film surface quality with rigid and soft contact lenses

Objectives: To measure tear film surface quality (TFSQ) using dynamic high-speed videokeratoscopy during short-term (8 hours) use of rigid and soft contact lenses. Methods: A group of fourteen subjects wore 3 different types of contact lenses on 3 different non-consecutive days (order randomized) in one eye only. Subjects were screened to exclude those with dry eye. The lenses included a PMMA hard, an RGP (Boston XO) and a soft silicone hydrogel lens. Three 30 second long high speed videokeratoscopy recordings were taken with contact lenses in-situ, in the morning and again after 8 hours of contact lens wear, both in normal and suppressed blinking conditions. Recordings were also made on a baseline day with no contact lens wear. Results: The presence of a contact lens in the eye had a significant effect on the mean TFSQ in both natural and suppressed blinking conditions (p=0.001 and p=0.01 respectively, repeated measures ANOVA). TFSQ was worse with all the lenses compared to no lens in the eye (in the afternoon during both normal and suppressed blinking conditions (all p<0.05). In natural blinking conditions, the mean TFSQ for the PMMA and RGP lenses was significantly worse than the baseline day (no lens) for both morning and afternoon measures (p<0.05). Conclusions: This study shows that both rigid and soft contact lenses adversely affect the TFSQ in both natural and suppressed blinking conditions. No significant differences were found between the lens types and materials. Keywords: Tear film surface quality, rigid contact lens, soft contact lens, dynamic high-speed videokeratoscopy

Diurnal Variation of Retinal Thickness with Spectral Domain OCT

Purpose. To investigate whether diurnal variation occurs in retinal thickness measures derived from spectral domain optical coherence tomography (SD-OCT). Methods. Twelve healthy adult subjects had retinal thickness measured with SD-OCT every 2 h over a 10 h period. At each measurement session, three average B-scan images were derived from a series of multiple B-scans (each from a 5 mm horizontal raster scan along the fovea, containing 1500 A-scans/B-scan) and analyzed to determine the thickness of the total retina, as well as the thickness of the outer retinal layers. Average thickness values were calculated at the foveal center, at the 0.5 mm diameter foveal region, and for the temporal parafovea (1.5 mm from foveal center) and nasal parafovea (1.5 mm from foveal center). Results. Total retinal thickness did not exhibit significant diurnal variation in any of the considered retinal regions (p > 0.05). Evidence of significant diurnal variation was found in the thickness of the outer retinal layers (p < 0.05), with the most prominent changes observed in the photoreceptor layers at the foveal center. The photoreceptor inner and outer segment layer thickness exhibited mean amplitude (peak to trough) of daily change of 7 ± 3 μm at the foveal center. The peak in thickness was typically observed at the third measurement session (mean measurement time, 13:06). Conclusions. The total retinal thickness measured with SD-OCT does not exhibit evidence of significant variation over the course of the day. However, small but significant diurnal variation occurs in the thickness of the foveal outer retinal layers.

Synthesizing and databasing fossil calibrations: divergence dating and beyond

Divergence dating studies, which combine temporal data from the fossil record with branch length data from molecular phylogenetic trees, represent a rapidly expanding approach to understanding the history of life. National Evolutionary Synthesis Center hosted the first Fossil Calibrations Working Group (3–6 March, 2011, Durham, NC, USA), bringing together palaeontologists, molecular evolutionists and bioinformatics experts to present perspectives from disciplines that generate, model and use fossil calibration data. Presentations and discussions focused on channels for interdisciplinary collaboration, best practices for justifying, reporting and using fossil calibrations and roadblocks to synthesis of palaeontological and molecular data. Bioinformatics solutions were proposed, with the primary objective being a new database for vetted fossil calibrations with linkages to existing resources, targeted for a 2012 launch.

The evolutionary history of cockatoos (Aves: Psittaciformes: Cacatuidae)

Cockatoos are the distinctive family Cacatuidae, a major lineage of the order of parrots (Psittaciformes) and distributed throughout the Australasian region of the world. However, the evolutionary history of cockatoos is not well understood. We investigated the phylogeny of cockatoos based on three mitochondrial and three nuclear DNA genes obtained from 16 of 21 species of Cacatuidae. In addition, five novel mitochondrial genomes were used to estimate time of divergence and our estimates indicate Cacatuidae diverged from Psittacidae approximately 40.7 million years ago (95% CI 51.6–30.3 Ma) during the Eocene. Our data shows Cacatuidae began to diversify approximately 27.9 Ma (95% CI 38.1–18.3 Ma) during the Oligocene. The early to middle Miocene (20–10 Ma) was a significant period in the evolution of modern Australian environments and vegetation, in which a transformation from mainly mesic to xeric habitats (e.g., fire-adapted sclerophyll vegetation and grasslands) occurred. We hypothesize that this environmental transformation was a driving force behind the diversification of cockatoos. A detailed multi-locus molecular phylogeny enabled us to resolve the phylogenetic placements of the Palm Cockatoo (Probosciger aterrimus), Galah (Eolophus roseicapillus), Gang-gang Cockatoo (Callocephalon fimbriatum) and Cockatiel (Nymphicus hollandicus), which have historically been difficult to place within Cacatuidae. When the molecular evidence is analysed in concert with morphology, it is clear that many of the cockatoo species’ diagnostic phenotypic traits such as plumage colour, body size, wing shape and bill morphology have evolved in parallel or convergently across lineages.