954 resultados para Structural evaluation
Resumo:
Evaluating the validity of formative variables has presented ongoing challenges for researchers. In this paper we use global criterion measures to compare and critically evaluate two alternative formative measures of System Quality. One model is based on the ISO-9126 software quality standard, and the other is based on a leading information systems research model. We find that despite both models having a strong provenance, many of the items appear to be non-significant in our study. We examine the implications of this by evaluating the quality of the criterion variables we used, and the performance of PLS when evaluating formative models with a large number of items. We find that our respondents had difficulty distinguishing between global criterion variables measuring different aspects of overall System Quality. Also, because formative indicators “compete with one another” in PLS, it may be difficult to develop a set of measures which are all significant for a complex formative construct with a broad scope and a large number of items. Overall, we suggest that there is cautious evidence that both sets of measures are valid and largely equivalent, although questions still remain about the measures, the use of criterion variables, and the use of PLS for this type of model evaluation.
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This paper illustrates a field research performed with a team of experts involved in the evaluation of Trippple, a system aimed at supporting the different phases of a tourist trip, in order to provide feedback and insights, both on the functionalities already implemented (that at the time of evaluation were available only as early and very unstable prototypes), and on the functionalities still to be implemented. We show how the involvement of professionals helped to focus on challenging aspects, instead of less important, cosmetic, issues and resulted profitable in terms of early feedback, issues spotted, and improvements suggested
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The purpose of this paper is to review the incidence of upper-body morbidity (arm and breast symptoms, impairments, and lymphedema), methods for diagnosis, and prevention and treatment strategies. It was also the purpose to highlight the evidence base for integration of prospective surveillance for upper-body morbidity within standard clinical care of women with breast cancer. Between 10% and 64% of women report upper-body symptoms between 6 months and 3 years after breast cancer, and approximately 20% develop lymphedema. Symptoms remain common into longer-term survivorship, and although lymphedema may be transient for some, those who present with mild lymphedema are at increased risk of developing moderate to severe lymphedema. The etiology of morbidity seems to be multifactorial, with the most consistent risk factors being those associated with extent of treatment. However, known risk factors cannot reliably distinguish between those who will and will not develop upper-body morbidity. Upper-body morbidity may be treatable with physical therapy. There is also evidence in support of integrating regular surveillance for upper-body morbidity into the routine care provided to women with breast cancer, with early diagnosis potentially contributing to more effective management and prevention of progression of these conditions.
Resumo:
We evaluated the Minnesota Multiphasic Personality Inventory-Second Edition (MMPI-2) Response Bias Scale (RBS). Archival data from 83 individuals who were referred for neuropsychological assessment with no formal diagnosis (n = 10), following a known or suspected traumatic brain injury (n = 36), with a psychiatric diagnosis (n = 20), or with a history of both trauma and a psychiatric condition (n = 17) were retrieved. The criteria for malingered neurocognitive dysfunction (MNCD) were applied, and two groups of participants were formed: poor effort (n = 15) and genuine responders (n = 68). Consistent with previous studies, the difference in scores between groups was greatest for the RBS (d = 2.44), followed by two established MMPI-2 validity scales, F (d = 0.25) and K (d = 0.23), and strong significant correlations were found between RBS and F (rs = .48) and RBS and K (r = −.41). When MNCD group membership was predicted using logistic regression, the RBS failed to add incrementally to F. In a separate regression to predict group membership, K added significantly to the RBS. Receiver-operating curve analysis revealed a nonsignificant area under the curve statistic, and at the ideal cutoff in this sample of >12, specificity was moderate (.79), sensitivity was low (.47), and positive and negative predictive power values at a 13% base rate were .25 and .91, respectively. Although the results of this study require replication because of a number of limitations, this study has made an important first attempt to report RBS classification accuracy statistics for predicting poor effort at a range of base rates.
Resumo:
Capacity probability models of generating units are commonly used in many power system reliability studies, at hierarchical level one (HLI). Analytical modelling of a generating system with many units or generating units with many derated states in a system, can result in an extensive number of states in the capacity model. Limitations on available memory and computational time of present computer facilities can pose difficulties for assessment of such systems in many studies. A cluster procedure using the nearest centroid sorting method was used for IEEE-RTS load model. The application proved to be very effective in producing a highly similar model with substantially fewer states. This paper presents an extended application of the clustering method to include capacity probability representation. A series of sensitivity studies are illustrated using IEEE-RTS generating system and load models. The loss of load and energy expectations (LOLE, LOEE), are used as indicators to evaluate the application
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The reliable operation of the electrical system at Callide Power Station is of extreme importance to the normal everyday running of the Station. This study applied the principles of reliability to do an analysis on the electrical system at Callide Power Station. It was found that the level of expected outage cost increased exponentially with a declining level of maintenance. Concluding that even in a harsh economic electricity market where CS Energy tries and push their plants to the limit, maintenance must not be neglected. A number of system configurations were found to increase the reliability of the system and reduce the expected outage costs. A number of other advantages were identified as a result of using reliability principles to do this study on the Callide electrical system configuration.
Resumo:
My quantitative study asks how Chinese Australians’ “Chineseness” and their various resources influence their Chinese language proficiency, using online survey and snowball sampling. ‘Operationalization’ is a challenging process which ensures that the survey design talks back to the informing theory and forwards to the analysis model. It requires the attention to two core methodological concerns, namely ‘validity’ and ‘reliability’. Construction of a high-quality questionnaire is critical to the achievement of valid and reliable operationalization. A series of strategies were chosen to ensure the quality of the questions, and thus the eventual data. These strategies enable the use of structural equation modelling to examine how well the data fits the theoretical framework, which was constructed in light of Bourdieu’s theory of habitus, capital and field.
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This article focuses on the evaluation of thesis supervision and highlights the vast range of problem areas presently documented as significant areas of concern for both graduate students and their supervisors. Additionally, the authors report on a study completed in 1995, which surveyed all Australian universities about current evaluative practices in postgraduate supervision. The conclusion of this study was that the conduct of such evaluations appears to be minimal and is primarily designed to obtain an indicator of the general “health” of a university's postgraduate supervision rather than to foster improved supervisory practices. As part of the same study, the authors conducted University faculty-based student and supervisor focus groups. Key issues emerging from these focus groups were: (1) the importance of relational aspects of supervision as the student communicates over the long term with one or more supervisors; (2) the importance of systematic feedback, monitoring, and evaluation to the supervisory process; and (3) the lack of strategies to facilitate this evaluative feedback process. On the basis of these findings, the authors designed evaluative strategies to facilitate regular ongoing feedback between students and supervisors.
Resumo:
Noradrenaline which occurs naturally in the body binds to beta-adrenoceptors on the heart, causing the heart to beat faster and with greater force in response to increased demand. This enables the heart to provide oxygenated blood to vital organs. Prolonged overstimulation by noradrenaline can be harmful to the heart and lead to the progression of heart disease. In these circumstances beta-adrenoceptors are blocked with drugs called beta-blockers. Beta-blockers block the effects of noradrenaline by binding to the same site on the beta-adrenoceptor. Some beta-blockers such as CGP12177 can also cause increases in heart rate. Therefore it was proposed that CGP12177 could bind in a different place to noradrenaline. The aim of this study was to determine where CGP12177 binds to on the beta-adrenoceptor. The results have revealed a separate binding site named beta-1-low. These results may lead to the development of improved -blockers for the management of heart conditions.
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Shared services are increasingly prevalent in practice, their introduction potentially entailing substantive and highly consequential organizational redesign. Yet, attention to the structural arrangements of shared services has been limited. This study explores types of structural arrangements for shared services that are observed in practice, and the salient dimensions along which those types can be usefully differentiated. Through inductive attention to the shared services literature, and content analysis of 36 secondary case studies of shared services in the higher education sector, three salient dimensions emerged: (1) the existence or not of a separate organizational entity, (2) an intra- or inter-organizational sharing boundary, and (3) involvement or not of a third party. Each dimension being dichotomous yields 23 combinations, or eight shared services structural arrangement types. Each of the eight structural arrangement types is defined and demonstrated through case examples. The typology offers clarity around shared services structural arrangements. It can serve as a useful analytical tool for researchers investigating the phenomenon further, and for practitioners considering the introduction or further development of shared services arrangements. Important follow on research is suggested too.
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Ebola virus is a highly pathogenic filovirus causing severe hemorrhagic fever with high mortality rates. It assembles heterogenous, filamentous, enveloped virus particles containing a negative-sense, single-stranded RNA genome packaged within a helical nucleocapsid (NC). We have used cryo-electron microscopy and tomography to visualize Ebola virus particles, as well as Ebola virus-like particles, in three dimensions in a near-native state. The NC within the virion forms a left-handed helix with an inner nucleoprotein layer decorated with protruding arms composed of VP24 and VP35. A comparison with the closely related Marburg virus shows that the N-terminal region of nucleoprotein defines the inner diameter of the Ebola virus NC, whereas the RNA genome defines its length. Binding of the nucleoprotein to RNA can assemble a loosely coiled NC-like structure; the loose coil can be condensed by binding of the viral matrix protein VP40 to the C terminus of the nucleoprotein, and rigidified by binding of VP24 and VP35 to alternate copies of the nucleoprotein. Four proteins (NP, VP24, VP35, and VP40) are necessary and sufficient to mediate assembly of an NC with structure, symmetry, variability, and flexibility indistinguishable from that in Ebola virus particles released from infected cells. Together these data provide a structural and architectural description of Ebola virus and define the roles of viral proteins in its structure and assembly
Resumo:
Work integration social enterprises (WISE) seek to create employment and pathways to employment for those highly disadvantaged in the labour market. This chapter examines the effects of WISE on the wellbeing of immigrants and refugees experiencing multiple barriers to economic and social participation. Drawing on an evaluation of a programme that supports seven such enterprises in the Australian state of Victoria, the effects of involvement for individual participants and their communities are examined. The study finds that this social enterprise model affords unique local opportunities for economic and social participation for groups experiencing significant barriers to meaningful employment. These opportunities have a positive impact on individual and community-level wellbeing. However, the financial costs of the model are high relative to other employment programmes, which is consistent with international findings on intermediate labour market programmes. The productivity costs of WISE are also disproportionately high compared to private sector competitors in some industries. This raises considerable dilemmas for social enterprise operators seeking to produce social value and achieve business sustainability while bearing high productivity costs to fulfil their mission. Further, the evaluation illuminates an ongoing need to address the systemic and structural drivers of health and labour market inequalities that characterize socio-economic participation for immigrants and refugees.
Resumo:
The project examined the responsiveness of the telenursing service provided by the Child Health Line (hereinafter referred to as CHL). It aimed to provide an account of population usage of the service, the call request types and the response of the service to the calls. In so doing, the project extends the current body of knowledge pertaining to the provision of parenting support through telenursing. Approximately 900 calls to the CHL were audio-recorded over the December 2005-2006 Christmas-New Year period. A protocol was developed to code characteristics of the call, the interactional features between the caller and nurse call-taker, and the extent to which there was (a) agreement on problem definition and the plan of action and (b) interactional alignment between nurse and caller. A quantitative analysis examined the frequencies of the main topics covered in calls to the CHL and any statistical associations between types of calls, length of calls and nurse-caller alignment. In addition, a detailed qualitative analysis was conducted on a subset of calls dealing with the nurse management of calls seeking medical advice and information. Key findings include: • Overall, 74% of the calls discussed parenting and child development issues, 48% discussed health/medical issues, and 16% were information-seeking calls. • More specifically: o 21% discussed health/medical and parenting and child development issues. o 3% discussed parenting and information-seeking issues. o 5% discussed health/medical, parenting/development and information issues. o 18% exclusively focussed on health and medical issues and therefore were outside the remit of the intended scope of the CHL. These calls caused interactional dilemmas for the nurse call-takers as they simultaneously dealt with parental expectations for help and the CHL guidelines indicating that offering medical advice was outside the remit of the service. • Most frequent reasons for calling were to discuss sleep, feeding, normative infant physical functions and parenting advice. • The average length of calls to the CHL was 7 minutes. • Longer calls were more likely to involve nurse call-takers giving advice on more than one topic, the caller displaying strong emotions, the caller not specifically providing the reason for the call, and the caller discussing parenting and developmental issues. • Shorter calls were characterised by the nurse suggesting that the child receive immediate medical attention, the nurse emphasising the importance or urgency of the plan of action, the caller referring to or requesting confirmation of a diagnosis, and caller and nurse call-taker discussion of health and medical issues. • The majority of calls, 92%, achieved parent-nurse alignment by the conclusion of the call. However, 8% did not. • The 8% of calls that were not aligned require further quantitative and qualitative investigation of the interactional features. The findings are pertinent in the current context where Child Health Line now resides within 13HEALTH. These findings indicate: 1. A high demand for parenting advice. 2. Nurse call-takers have a high level of competency in dealing with calls about parenting and normal child development, which is the remit of the CHL. 3. Nurse call-takers and callers achieve a high degree of alignment when both parties agree on a course of action. 4. There is scope for developing professional practice in calls that present difficulties in terms of call content, interactional behaviour and call closure. Recommendations of the project: 1. There are numerous opportunities for further research on interactional aspects of calls to the CHL, such as further investigations of the interactional features and the association of the features to alignment and nonalignment. The rich and detailed insights into the patterns of nurse-parent interactions were afforded by the audio-recording and analysis of calls to the CHL. 2. The regular recording of calls would serve as a way of increasing understanding of the type and nature of calls received, and provide a valuable training resource. Recording and analysing calls to CHL provides insight into the operation of the service, including evidence about the effectiveness of triaging calls. 3. Training in both recognising and dealing with problem calls may be beneficial. For example, calls where the caller showed strong emotion, appeared stressed, frustrated or troubled were less likely to be rated as aligned calls. In calls where the callers described being ‘at their wits end’, or responded to each proposed suggestion with ‘I’ve tried that’, the callers were fairly resistant to advice-giving. 4. Training could focus on strategies for managing calls relating to parenting support and advice, and parental well-being. The project found that these calls were more likely to be rated as being nonaligned. 5. With the implementation of 13HEALTH, future research could compare nurse-parent interaction following the implementation of triaging. Of the calls, 21% had both medical and parenting topics discussed and 5.3% discussed medical, parenting and information topics. Added to this, in 12% of calls, there was ambiguity between the caller and nurse call-taker as to whether the problem was medical or behavioural.