907 resultados para Complexity score
Resumo:
Automated process discovery techniques aim at extracting models from information system logs in order to shed light into the business processes supported by these systems. Existing techniques in this space are effective when applied to relatively small or regular logs, but otherwise generate large and spaghetti-like models. In previous work, trace clustering has been applied in an attempt to reduce the size and complexity of automatically discovered process models. The idea is to split the log into clusters and to discover one model per cluster. The result is a collection of process models -- each one representing a variant of the business process -- as opposed to an all-encompassing model. Still, models produced in this way may exhibit unacceptably high complexity. In this setting, this paper presents a two-way divide-and-conquer process discovery technique, wherein the discovered process models are split on the one hand by variants and on the other hand hierarchically by means of subprocess extraction. The proposed technique allows users to set a desired bound for the complexity of the produced models. Experiments on real-life logs show that the technique produces collections of models that are up to 64% smaller than those extracted under the same complexity bounds by applying existing trace clustering techniques.
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We consider the problem of maximizing the secure connectivity in wireless ad hoc networks, and analyze complexity of the post-deployment key establishment process constrained by physical layer properties such as connectivity, energy consumption and interference. Two approaches, based on graph augmentation problems with nonlinear edge costs, are formulated. The first one is based on establishing a secret key using only the links that are already secured by shared keys. This problem is in NP-hard and does not accept polynomial time approximation scheme PTAS since minimum cutsets to be augmented do not admit constant costs. The second one extends the first problem by increasing the power level between a pair of nodes that has a secret key to enable them physically connect. This problem can be formulated as the optimal key establishment problem with interference constraints with bi-objectives: (i) maximizing the concurrent key establishment flow, (ii) minimizing the cost. We prove that both problems are NP-hard and MAX-SNP with a reduction to MAX3SAT problem.
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Objective: To determine the impact of a free-choice diet on nutritional intake and body condition of feral horses. Animals: Cadavers of 41 feral horses from 5 Australian locations. Procedures: Body condition score (BCS) was determined (scale of 1 to 9), and the stomach was removed from horses during postmortem examination. Stomach contents were analyzed for nutritional variables and macroelement and microelement concentrations. Data were compared among the locations and also compared with recommended daily intakes for horses. Results: Mean BCS varied by location; all horses were judged to be moderately thin. The BCS for males was 1 to 3 points higher than that of females. Amount of protein in the stomach contents varied from 4.3% to 14.9% and was significantly associated with BCS. Amounts of water-soluble carbohydrate and ethanol-soluble carbohydrate in stomach contents of feral horses from all 5 locations were higher than those expected for horses eating high-quality forage. Some macroelement and microelement concentrations were grossly excessive, whereas others were grossly deficient. There was no evidence of ill health among the horses. Conclusions and Clinical Relevance: Results suggested that the diet for several populations of feral horses in Australia appeared less than optimal. However, neither low BCS nor trace mineral deficiency appeared to affect survival of the horses. Additional studies on food sources in these regions, including analysis of water-soluble carbohydrate, ethanol-soluble carbohydrate, and mineral concentrations, are warranted to determine the provenance of such rich sources of nutrients. Determination of the optimal diet for horses may need revision.
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While maternal obesity, excess pregnancy weight gain and lifestyle behaviours are associated with future overweight for both mothers and babies, there is limited research on how best to intervene. An evidence base that identifies behavioural influences is crucial to the development of effective interventions. This thesis aims to gain an understanding of maternal behavioural outcomes of healthy eating, physical activity and gestational weight gain (GWG), the psychosocial influences on these and to examine differences according to pre-pregnancy weight status. The New Beginnings Healthy Mothers and Babies Study was a prospective observational study using the PRECEDE-PROCEED model of health promotion planning as a framework. A consecutive sample of 715 women was recruited. Height and weight were measured and women completed questionnaires at approximately 16 and 36 weeks gestation. This thesis presents three chapters of original research across four study domains. While healthy eating was widely regarded as important during pregnancy and had become more so, there was more variability in attitudes towards physical activity. Ninety-two percent of participants achieved the maximum knowledge score relating to the influence of nutrition on pregnancy. However, 8% and 36% respectively knew how many serves of fruit and vegetables should be consumed daily. Six percent of participants met the recommendations for fruit consumption, 4% achieved the recommended vegetable intake and 44% achieved sufficient physical activity. There were few differences between healthy and overweight women for measures of physical activity and healthy eating. Many predisposing, reinforcing and enabling factors with a positive influence on health behaviours were lower in women commencing pregnancy overweight and those factors with a negative influence on health behaviours were higher when compared to healthy weight women. Some of these antecedents to health behaviours that were different according to prepregnancy weight status were associated with diet quality and physical activity. While self efficacy was consistently associated with diet quality and physical activity for both weight groups, other associations between specific predisposing, reinforcing and enabling factors differed with behaviour and weight status group. These results highlight the complexity of supporting behaviour change in a one-size-fits-all approach. Sixty-four percent of participants gained weight outside of recommendations. Compared to healthy weight women, those women who were already overweight at the beginning of pregnancy were more likely to gain too much weight (30% vs 56%, p<0.001). Only 35% of participants reported their correct recommended weight gain. Excess GWG was associated with few predisposing factors, however, these were not consistent between prepregnancy weight status groups. Less than 50% of women reported sometimes/usually/always receiving advice from health professionals relating to healthy eating, physical activity or GWG. These results indicate that there are opportunities to improve the advice and support provided by health care professionals in the antenatal period. Evidence from this PhD research suggests that there is a need for effective prevention and management of excess weight in pregnancy. Effective management of this problem is likely to require a multidisciplinary approach with multi-level strategies. Importantly, the strategies may need to be tailored according to pre-pregnancy weight status. Collectively, the evidence derived from this thesis suggests that opportunities to support healthy lifestyles and prevent future overweight are being missed during pregnancy.
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I read with interest the article in Angiology that determined the role of anxiety level on radial artery spasm during transradial coronary angiography.1 As the importance of conducting more randomised controlled trials using anxiolytics to define the relation between anxiety and vasospasm was noted by the authors, I offer the following insights for investigators to consider when conducting such research. While previous research has already identified that moderate procedural sedation and opioid analgesia reduces the incidence of vasospasm,2 the identification of risk factors in the present study is hypothesis generating as to how outcomes might be even further improved. It is possible that selectively applying either even more intensive sedation and analgesia or complementary non-pharmacological stress-reducing therapies, such as music therapy or visualisation and attentive behaviour, to patients ‘at-risk’ of vasospasm (women and those with high levels of anxiety prior to the procedure) might lead to even better patient outcomes...
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In this study, a tandem LC-MS (Waters Xevo TQ) MRM-based MS method was developed for rapid, broad profiling of hydrophilic metabolites from biological samples, in either positive or negative ion modes without the need for an ion pairing reagent, using a reversed-phase pentafluorophenylpropyl (PFPP) column. The developed method was successfully applied to analyze various biological samples from C57BL/6 mice, including urine, duodenum, liver, plasma, kidney, heart, and skeletal muscle. As result, a total 112 of hydrophilic metabolites were detected within 8 min of running time to obtain a metabolite profile of the biological samples. The analysis of this number of hydrophilic metabolites is significantly faster than previous studies. Classification separation for metabolites from different tissues was globally analyzed by PCA, PLS-DA and HCA biostatistical methods. Overall, most of the hydrophilic metabolites were found to have a "fingerprint" characteristic of tissue dependency. In general, a higher level of most metabolites was found in urine, duodenum, and kidney. Altogether, these results suggest that this method has potential application for targeted metabolomic analyzes of hydrophilic metabolites in a wide ranges of biological samples.
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Prior to the completion of the human genome project, the human genome was thought to have a greater number of genes as it seemed structurally and functionally more complex than other simpler organisms. This along with the belief of “one gene, one protein”, were demonstrated to be incorrect. The inequality in the ratio of gene to protein formation gave rise to the theory of alternative splicing (AS). AS is a mechanism by which one gene gives rise to multiple protein products. Numerous databases and online bioinformatic tools are available for the detection and analysis of AS. Bioinformatics provides an important approach to study mRNA and protein diversity by various tools such as expressed sequence tag (EST) sequences obtained from completely processed mRNA. Microarrays and deep sequencing approaches also aid in the detection of splicing events. Initially it was postulated that AS occurred only in about 5%; of all genes but was later found to be more abundant. Using bioinformatic approaches, the level of AS in human genes was found to be fairly high with 35-59%; of genes having at least one AS form. Our ability to determine and predict AS is important as disorders in splicing patterns may lead to abnormal splice variants resulting in genetic diseases. In addition, the diversity of proteins produced by AS poses a challenge for successful drug discovery and therefore a greater understanding of AS would be beneficial.
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A loss of function mutation in the TRESK K2P potassium channel (KCNK18), has recently been linked with typical familial migraine with aura. We now report the functional characterisation of additional TRESK channel missense variants identified in unrelated patients. Several variants either had no apparent functional effect, or they caused a reduction in channel activity. However, the C110R variant was found to cause a complete loss of TRESK function, yet is present in both sporadic migraine and control cohorts, and no variation in KCNK18 copy number was found. Thus despite the previously identified association between loss of TRESK channel activity and migraine in a large multigenerational pedigree, this finding indicates that a single non-functional TRESK variant is not alone sufficient to cause typical migraine and highlights the genetic complexity of this disorder. Migraine is a common, disabling neurological disorder with a genetic, environmental and in some cases hormonal component. It is characterized by attacks of severe, usually unilateral and throbbing headache, can be accompanied by nausea, vomiting and photophobia and is clinically divided into two main subtypes, migraine with aura (MA) when a migraine is accompanied by transient and reversible focal neurological symptoms and migraine without aura (MO)1. The multifactorial and clinical heterogeneity of the disorder have considerably hindered the identification of common migraine susceptibility genes and most of our current understanding comes from the studies of familial hemiplegic migraine (FHM), a rare monogenic autosomal dominant form of MA2. So far, the three susceptibility genes that have been convincingly identified in FHM families all encode ion channels or transporters: CACNA1A encoding the α1 subunit of the Cav2.1 calcium channel3, SCN1A encoding the Nav1.1 sodium channel4 and ATP1A2 encoding the α2 subunit of the Na+/K+ pump5. It is believed that mutations in these genes may lead to increased efflux of glutamate and potassium in the synapse and thereby cause migraine by rendering the brain more susceptible to cortical spreading depression (CSD)6 which is thought to play a role in initiating a migraine attack7,8. However, these genes have not to date been implicated in common forms of migraine9. Nevertheless, current opinion suggests that typical migraine, like FHM, is also disorder of neuronal excitability, ion homeostasis and neurotransmitter release10,11,12. Mutations in the SLC4A4 gene encoding the sodium-bicarbonate cotransporter NBCe1, have recently been implicated in several different forms of migraine13, and a variety of genes involved in glutamate homeostasis (PGCP, MTDH14 and LRP115) and a cation channel (TRPM8)15 have also recently been implicated in migraine via genome-wide association studies. Ion channels are therefore highly likely to play an important role in the pathogenesis of typical migraine. TRESK (KCNK18), is a member of the two-pore domain (K2P) family of potassium channels involved in the control of cellular electrical excitability16. Regulation of TRESK activity by the calcium-dependent phosphatase calcineurin17, as well as its expression in dorsal root ganglia (DRG)18 and trigeminal ganglia (TG)19,20 has led to a proposed role for this channel in a variety of pain pathways. In a recent study, a frameshift mutation (F139Wfsx24) in TRESK was identified in a large multigenerational pedigree where it co-segregated perfectly with typical MA and a significant genome-wide linkage LOD score of 3.0. Furthermore, functional analysis revealed that this mutation caused a complete loss of TRESK function and that the truncated subunit was also capable of down regulating wild-type channel function. This therefore highlighted KCNK18 as potentially important candidate gene and suggested that TRESK dysfunction might play a possible role in the pathogenesis of familial migraine with visual aura20. Additional screening for KCNK18 mutations in unrelated sporadic migraine and control cohorts also identified a number of other missense variants; R10G, A34V, C110R, S231P and A233V20. The A233V variant was found only in the control cohort, whilst A34V was identified in a single Australian migraine proband for which family samples were not available, but it was not detected in controls. By contrast, the R10G, C110R, and S231P variants were found in both migraineurs and controls in both cohorts. In this study, we have investigated the functional effect of these variants to further probe the potential association of TRESK dysfunction with typical migraine.
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Project Management (PM) as an academic field is relatively new in Australian universities. Moreover, the field is distributed across four main areas: business (management), built environment and construction, engineering and more recently ICT (information systems). At an institutional level, with notable exceptions, there is little engagement between researchers working in those individual areas. Consequently, an initiative was launched in 2009 to create a network of PM researchers to build a disciplinary base for PM in Australia. The initiative took the form of a bi-annual forum. The first forum established the constituency and spread of PM research in Australia (Sense et al., 2011). This special issue of IJPM arose out of the second forum, held in 2012, that explored the notion of an Australian perspective on PM. At the forum, researchers were invited to collaborate to explore issues, methodological approaches, and theoretical positions underpinning their research and to answer the question: is there a distinctly Australian research agenda which responds to the current challenges of large and complex projects in our region? From a research point of view, it was abundantly clear at the forum that many of the issues facing Australian researchers are shared around the world. However, what emerged from the forum as the Australian perspective was a set of themes and research issues that dominate the Australia research agenda.
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Using a quasi-natural voting experiment encompassing a 160-year period (1848–2009) in Switzerland, we investigate whether a higher level of complexity leads to increased reliance on trusted parliamentary representatives. We find that when more referenda are held on the same day, constituents are more likely to refer to parliamentary recommendations when making their decisions. This finding holds true even when we narrow our focus to referenda with a relatively lower voter turnout on days on which more than one referendum is held. We also demonstrate that when constituents face a higher level of complexity, they follow the parliamentary recommendations rather than those of interest groups. "Viewed as a geometric figure, the ant’s path is irregular, complex, hard to describe. But its complexity is really a complexity in the surface of the beach, not a complexity in the ant." ([1] p. 51)
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Objectives The intent of this paper is in the examination of health IT implementation processes – the barriers to and facilitators of successful implementation, identification of a beginning set of implementation best practices, the identification of gaps in the health IT implementation body of knowledge, and recommendations for future study and application. Methods A literature review resulted in the identification of six health IT related implementation best practices which were subsequently debated and clarified by participants attending the NI2012 Research Post Conference held in Montreal in the summer of 2012. Using the framework for implementation research (CFIR) to guide their application, the six best practices were applied to two distinct health IT implementation studies to assess their applicability. Results Assessing the implementation processes from two markedly diverse settings illustrated both the challenges and potentials of using standardized implementation processes. In support of what was discovered in the review of the literature, “one size fits all” in health IT implementation is a fallacy, particularly when global diversity is added into the mix. At the same time, several frameworks show promise for use as “scaffolding” to begin to assess best practices, their distinct dimensions, and their applicability for use. Conclusions Health IT innovations, regardless of the implementation setting, requires a close assessment of many dimensions. While there is no “one size fits all”, there are commonalities and best practices that can be blended, adapted, and utilized to improve the process of implementation. This paper examines health IT implementation processes and identifies a beginning set of implementation best practices, which could begin to address gaps in the health IT implementation body of knowledge.
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Organizational transformations reliant on successful ICT system developments (continue to) fail to deliver projected benefits even when contemporary governance models are applied rigorously. Modifications to traditional program, project and systems development management methods have produced little material improvement to successful transformation as they are unable to routinely address the complexity and uncertainty of dynamic alignment of IS investments and innovation. Complexity theory provides insight into why this phenomenon occurs and is used to develop a conceptualization of complexity in IS-driven organizational transformations. This research-in-progress aims to identify complexity formulations relevant to organizational transformation. Political/power based influences, interrelated business rules, socio-technical innovation, impacts on stakeholders and emergent behaviors are commonly considered as characterizing complexity while the proposed conceptualization accommodates these as connectivity, irreducibility, entropy and/or information gain in hierarchically approximation and scaling, number of states in a finite automata and/or dimension of attractor, and information and/or variety.
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Review(s) of: Settling the Pop Score: Pop Texts and Identity Politics, Stan Hawkins, Aldershot, Hants. : Ashgate, 2002, ISBN 0 7546 0352 0; pb, 234pp, ill, music exx, bibl. , discog. , index. The scholarly study of popular music has its origins in sociology and cultural studies, disciplinary areas in which musical meaning is often attributed to aspects of economical and sociological function. Against this tradition, recent writers have offered what is now referred to as ‘popular musicology’: a method or approach that tends towards a specific engagement with ‘pop texts’ on aesthetic, and perhaps even ‘musical’ terms. Stan Hawkins uses the term popular musicology ‘at his own peril,’ clearly recognising the implicit scholarly danger in his approach, whereby ‘formalist questions of musical analysis’ are dealt with ‘alongside the more intertextual discursive theorisations of musical expression’ (p. xii). In other words, popular musicologists dare to tread that fine line between text and context. As editor of the journal Popular Musicology Online, Hawkins is a leading advocate of this practice, specifically in the application of music-analytical techniques to popular music. His methodology attests to the influence of other leading figures in the area, notably Richard Middleton, Allan F. Moore and Derek Scott (general editor of the Ashgate Popular and Folk Music Series in which this book is published).
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This paper contributes to conversations about the funding and quality of education research. The paper proceeds in two parts. Part I sets the context by presenting an historical analysis of funding allocations made to Education research through the ARC’s Discovery projects scheme between the years 2002 and 2014, and compares these trends to allocations made to another field within the Social, Behavioural and Economic Sciences assessment panel: Psychology and Cognitive Science. Part II highlights the consequences of underfunding education research by presenting evidence from an Australian Research Council Discovery project that is tracking the experiences of disaffected students who are referred to behaviour schools. The re-scoping decisions that became necessary and the incidental costs that accrue from complications that occur in the field are illustrated and discussed through vignettes of research with “ghosts” who don’t like school but who do like lollies, chess and Lego.