951 resultados para subjective certainty


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Substation Automation Systems have undergone many transformational changes triggered by improvements in technologies. Prior to the digital era, it made sense to confirm that the physical wiring matched the schematic design by meticulous and laborious point to point testing. In this way, human errors in either the design or the construction could be identified and fixed prior to entry into service. However, even though modern secondary systems today are largely computerised, we are still undertaking commissioning testing using the same philosophy as if each signal were hard wired. This is slow and tedious and doesn’t do justice to modern computer systems and software automation. One of the major architectural advantages of the IEC 61850 standard is that it “abstracts” the definition of data and services independently of any protocol allowing the mapping of them to any protocol that can meet the modelling and performance requirements. On this basis, any substation element can be defined using these common building blocks and are made available at the design, configuration and operational stages of the system. The primary advantage of accessing data using this methodology rather than the traditional position method (such as DNP 3.0) is that generic tools can be created to manipulate data. Self-describing data contains the information that these tools need to manipulate different data types correctly. More importantly, self-describing data makes the interface between programs robust and flexible. This paper proposes that the improved data definitions and methods for dealing with this data within a tightly bound and compliant IEC 61850 Substation Automation System could completely revolutionise the need to test systems when compared to traditional point to point methods. Using the outcomes of an undergraduate thesis project, we can demonstrate with some certainty that it is possible to automatically test the configuration of a protection relay by comparing the IEC 61850 configuration extracted from the relay against its SCL file for multiple relay vendors. The software tool provides a quick and automatic check that the data sets on a particular relay are correct according to its CID file, thus ensuring that no unexpected modifications are made at any stage of the commissioning process. This tool has been implemented in a Java programming environment using an open source IEC 61850 library to facilitate the server-client association with the relay.

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Practice uncertainty occurs when health care providers feel uncomfortable in response to unfamiliar or challenging patient care situations. Practice uncertainty is inevitable in health care, and there are many contextual factors that can lead to either good or bad outcomes for patients and health care providers. Practice uncertainty is not a well-established concept in the literature, perhaps because of the predominant empirical paradigm and the high value placed on certainty within current health care culture. This study was conducted to explore practice uncertainty and bring this topic into the foreground as a first step toward practice evolution. A shift in the perception of practice uncertainty may change the way in which practitioners experience this phenomenon. This process must start with nursing educators recognizing and acknowledging this phenomenon when it occurs.

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Background Demand for essential plasma-derived products is increasing. Purpose This prospective study aims to identify predictors of voluntary non-remunerated whole blood (WB) donors becoming plasmapheresis donors. Methods Surveys were sent to WB donors who had recently (recent n = 1,957) and not recently donated (distant n = 1,012). Theory of Planned Behavior (TPB) constructs (attitude, subjective norm, self-efficacy) were extended with moral norm, anticipatory regret, and donor identity. Intentions and objective plasmapheresis donation for 527 recent and 166 distant participants were assessed. Results Multi-group analysis revealed that the model was a good fit. Moral norm and self-efficacy were positively associated while role identity (suppressed by moral norm) was negatively associated with plasmapheresis intentions. Conclusions The extended TPB was useful in identifying factors that facilitate conversion from WB to plasmapheresis donation. A superordinate donor identity may be synonymous with WB donation and, for donors with a strong moral norm for plasmapheresis, may inhibit conversion.

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Objective Relatively high rates of child restraint inappropriate use, misuse and faults in the installation of restraints have suggested a crucial need for public education messages to raise parental awareness of the need to use restraints correctly. This project involved the devising and pilot testing of message concepts, filming of a television advertisement (the TVC), and the evaluation of the TVC. This paper focuses specifically upon the evaluation of the TVC. The development and evaluation of the TVC were guided by an extended Theory of Planned Behaviour which comprised the standard constructs of attitude, subjective norm, and perceived behavioural control as well as the additional constructs of group norm and descriptive norm. The study also explored the extent to which parents with low and high intentions to self-check restraint/s differed on salient beliefs regarding the behaviour. Methods An online survey of parents (N = 384) was conducted where parents were randomly assigned to either an Intervention group (n = 161), and therefore viewed the advertisement within the survey, or the Control group (n = 223) and therefore did not view the advertisement. Results Following a one-off exposure to the TVC, the results indicated that, although not a significant difference, parents in the Intervention group reported stronger intentions (M = 4.43, SD = .74) to self-check restraints than parents in the Control group (M = 4.18, SD = .86). Also, parents in the Intervention group (M = 4.59, SD = .47) reported significantly higher levels of perceived behavioural control than parents in the Control group (M = 4.40, SD = .73). The regression results revealed that, for parents in the Intervention group, attitude and group norm were significant predictors of parental intentions to self-check their child restraint. Finally, the exploratory analyses of parental beliefs suggested that those parents with low intentions to self-check child restraints were significantly more likely than high intenders to agree that they did not have enough time to check restraints or that having a child in a restraint is more important than checking the installation of the restraint. Conclusion Overall, the findings provide some support for the persuasiveness of the child restraint TVC and provide insight into the factors influencing reported parental intentions as well as salient beliefs underpinning self-checking of restraints. Interventions that attempt to increase parental perceptions of the importance of self-checking restraints regularly and brevity of the time involved in doing so may be effective.

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Objective The objective of this study was to determine the roadside prevalence of alcohol-impaired driving among drivers and riders in northern Ghana. The study also verifies motorists’ perception on their own alcohol use and knowledge of legal Blood Alcohol Concentration (BAC) limit of Ghana. Method With the assistance of police, the systematic random sampling was used to collect data at roadblocks using a cross-sectional study design. Breathalyzers were used to screen whether motorists had detectable alcohol in their breath and a follow-up breath tests conducted to measure the actual breath alcohol levels among positive participants. Results In all, 9.7% of the 789 participants had detectable alcohol among whom 6% exceeded the legal (BAC) limit of 0.08%. The prevalence of alcohol-impaired driving/riding was highest among cyclists (10% of all cyclists breath tested) followed by truck drivers 9% and motorcyclists (7% of all motorcyclists breath tested). The occurrence of a positive BAC among cyclists was about 8 times higher, (OR=7.73; p<0.001) and 2 times higher, among motorcyclists (OR=2.30; p=0.039) compared with private car drivers. The likelihood for detecting a positive BAC among male motorists/riders was higher than females (OR=1.67; p=0.354). The odds for detecting a positive BAC among weekend motorists/riders was significantly higher than weekdays (OR=2.62; p=0.001). Conclusion Alcohol-impaired driving/riding in Ghana is high by international standards. In order to attenuate the harmful effects of alcohol misuse such as alcohol-impaired driving/riding, there is the need to educate road users about how much alcohol they can consume and stay below the legal limit. The police should also initiate random breath testing to instil the deterrence of detection, certainty of apprehension and punishment, and severity and celerity of punishment among drink-driving motorists and riders.

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Objective To analyze the ability to discriminate between healthy individuals and individuals with chronic nonspecific low back pain (CNLBP) by measuring the relation between patient-reported outcomes and objective clinical outcome measures of the erector spinae (ES) muscles using an ultrasound during maximal isometric lumbar extension. Design Cross-sectional study with screening and diagnostic tests with no blinded comparison. Setting University laboratory. Participants Healthy individuals (n=33) and individuals with CNLBP (n=33). Interventions Each subject performed an isometric lumbar extension. With the variables measured, a discriminate analysis was performed using a value ≥6 in the Roland and Morris disability questionnaire (RMDQ) as the grouping variable. Then, a logistic regression with the functional and architectural variables was performed. A new index was obtained from each subject value input in the discriminate multivariate analysis. Main Outcome Measures Morphologic muscle variables of the ES muscle were measured through ultrasound images. The reliability of the measures was calculated through intraclass correlation coefficients (ICCs). The relation between patient-reported outcomes and objective clinical outcome measures was analyzed using a discriminate function from standardized values of the variables and an analysis of the reliability of the ultrasound measurement. Results The reliability tests show an ICC value >.95 for morphologic and functional variables. The independent variables included in the analysis explained 42% (P=.003) of the dependent variable variance. Conclusions The relation between objective variables (electromyography, thickness, pennation angle) and a subjective variable (RMDQ ≥6) and the capacity of this relation to identify CNLBP within a group of healthy subjects is moderate. These results should be considered by clinicians when treating this type of patient in clinical practice.

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Purpose The aim of this paper is to empirically explore antecedents of local food purchase intention in two food producing countries with different cultural backgrounds. Design/methodology/approach An online survey was employed to collect data from consumers located in Chile (n=283) and Australia (n=300). A proposed model is tested with structural equation modelling (SEM). Findings Attitude towards consuming local food is a strong and direct driver of intentions to purchase local food in both countries. Attitude toward supporting local agri-businesses and consumer ethnocentrism are found to positively impact attitude towards consuming local food in both countries. Attitude towards local agri-businesses also has a direct effect on intentions to purchase local food in Australia, but not in Chile. Interestingly, subjective norms are not found to affect intentions to consume local food in either country. Research limitations/implications The paper examines factors affecting the attitude toward and behavioural intention regarding local food consumption and develops an extended model of local food consumption. An outcome of this new model is the inclusion of personal variables, which influence local food purchasing behaviour. Practical implications Producers and retailers need to develop campaigns explaining how consuming local food supports local businesses and farmers, which will reinforce personal values associated with local consumption. Originality/value This is the first study to demonstrate that positive attitudes toward local foods are important drivers of local food purchase behaviour, independent of the cultural characteristics or level of economic development within a country.

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To investigate potentially dissociable recognition memory responses in the hippocampus and perirhinal cortex, fMRI studies have often used confidence ratings as an index of memory strength. Confidence ratings, although correlated with memory strength, also reflect sources of variability, including task-irrelevant item effects and differences both within and across individuals in terms of applying decision criteria to separate weak from strong memories. We presented words one, two, or four times at study in each of two different conditions, focused and divided attention, and then conducted separate fMRI analyses of correct old responses on the basis of subjective confidence ratings or estimates from single- versus dual-process recognition memory models. Overall, the effect of focussing attention on spaced repetitions at study manifested as enhanced recognition memory performance. Confidence- versus model-based analyses revealed disparate patterns of hippocampal and perirhinal cortex activity at both study and test and both within and across hemispheres. The failure to observe equivalent patterns of activity indicates that fMRI signals associated with subjective confidence ratings reflect additional sources of variability. The results are consistent with predictions of single-process models of recognition memory.

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Word frequency (WF) and strength effects are two important phenomena associated with episodic memory. The former refers to the superior hit-rate (HR) for low (LF) compared to high frequency (HF) words in recognition memory, while the latter describes the incremental effect(s) upon HRs associated with repeating an item at study. Using the "subsequent memory" method with event-related fMRI, we tested the attention-at-encoding (AE) [M. Glanzer, J.K. Adams, The mirror effect in recognition memory: data and theory, J. Exp. Psychol.: Learn Mem. Cogn. 16 (1990) 5-16] explanation of the WF effect. In addition to investigating encoding strength, we addressed if study involves accessing prior representations of repeated items via the same mechanism as that at test [J.L. McClelland, M. Chappell, Familiarity breeds differentiation: a subjective-likelihood approach to the effects of experience in recognition memory, Psychol. Rev. 105 (1998) 724-760], entailing recollection [K.J. Malmberg, J.E. Holden, R.M. Shiffrin, Modeling the effects of repetitions, similarity, and normative word frequency on judgments of frequency and recognition memory, J. Exp. Psychol.: Learn Mem. Cogn. 30 (2004) 319-331] and whether less processing effort is entailed for encoding each repetition [M. Cary, L.M. Reder, A dual-process account of the list-length and strength-based mirror effects in recognition, J. Mem. Lang. 49 (2003) 231-248]. The increased BOLD responses observed in the left inferior prefrontal cortex (LIPC) for the WF effect provide support for an AE account. Less effort does appear to be required for encoding each repetition of an item, as reduced BOLD responses were observed in the LIPC and left lateral temporal cortex; both regions demonstrated increased responses in the conventional subsequent memory analysis. At test, a left lateral parietal BOLD response was observed for studied versus unstudied items, while only medial parietal activity was observed for repeated items at study, indicating that accessing prior representations at encoding does not necessarily occur via the same mechanism as that at test, and is unlikely to involve a conscious recall-like process such as recollection. This information may prove useful for constraining cognitive theories of episodic memory.

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In this paper, we use an experimental design to compare the performance of elicitation rules for subjective beliefs. Contrary to previous works in which elicited beliefs are compared to an objective benchmark, we consider a purely subjective belief framework (confidence in one’s own performance in a cognitive task and a perceptual task). The performance of different elicitation rules is assessed according to the accuracy of stated beliefs in predicting success. We measure this accuracy using two main factors: calibration and discrimination. For each of them, we propose two statistical indexes and we compare the rules’ performances for each measurement. The matching probability method provides more accurate beliefs in terms of discrimination, while the quadratic scoring rule reduces overconfidence and the free rule, a simple rule with no incentives, which succeeds in eliciting accurate beliefs. Nevertheless, the matching probability appears to be the best mechanism for eliciting beliefs due to its performances in terms of calibration and discrimination, but also its ability to elicit consistent beliefs across measures and across tasks, as well as its empirical and theoretical properties.

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This study was undertaken to examine the main and interactive effects of work stress and work control on levels of adjustment. Work stress, behavioral control, and informational control were manipulated in an experimental setting in which participants (N = 192) completed an in-basket activity. Although minimal support was found for the main and interactive effects of objective work stress, behavioral control, and informational control on adjustment, analyses involving the subjective measures of these variables revealed strong support for the proposal that work stress, behavioral control, and informational control would exert main effects on adjustment. There was also evidence that subjective levels of behavioral control buffered the negative effects of subjective work stress on positive mood, subjective task performance, and task satisfaction.

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Two experimental studies were conducted to examine whether the stress-buffering effects of behavioral control on work task responses varied as a function of procedural information. Study 1 manipulated low and high levels of task demands, behavioral control, and procedural information for 128 introductory psychology students completing an in-basket activity. ANOVA procedures revealed a significant three-way interaction among these variables in the prediction of subjective task performance and task satisfaction. It was found that procedural information buffered the negative effects of task demands on ratings of performance and satisfaction only under conditions of low behavioral control. This pattern of results suggests that procedural information may have a compensatory effect when the work environment is characterized by a combination of high task demands and low behavioral control. Study 2 (N=256) utilized simple and complex versions of the in-basket activity to examine the extent to which the interactive relationship among task demands, behavioral control, and procedural information varied as a function of task complexity. There was further support for the stress-buffering role of procedural information on work task responses under conditions of low behavioral control. This effect was, however, only present when the in-basket activity was characterized by high task complexity, suggesting that the interactive relationship among these variables may depend on the type of tasks performed at work.

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The present study was designed to examine the main and interactive effects of task demands, work control, and task information on levels of adjustment. Task demands, work control, and task information were manipulated in an experimental setting where participants completed a letter-sorting activity (N= 128). Indicators of adjustment included measures of positive mood, participants' perceptions of task performance, and task satisfaction. Results of the present study provided some support for the main effects of objective task demands, work control, and task information on levels of adjustment. At the subjective level of analysis, there was some evidence to suggest that work control and task information interacted in their effects on levels of adjustment. There was minimal support for the proposal that work control and task information would buffer the negative effects of task demands on adjustment. There was, however, some evidence to suggest that the stress-buffering role of subjective work control was more marked at high, rather than low, levels of subjective task information.

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Obstructive sleep apnoea (OSA) is a chronic condition in which the upper airways collapse repeatedly during sleep, completely or partially obstructing breathing. This obstruction leads to chronic intermittent hypoxia and severe sleep fragmentation, disrupting the restorative functions of sleep. Beebe and Gozal (2002)a developed a theory which hypothesises that disruption of the restorative functions of sleep lead to a chronic low level brain damage most evident in executive functions (EF). Neuropsychological testing of EF, volumetric MRI, magnetic resonance spectroscopy, event related potentials and CSF biomarkers all provide support for this theory. Little research has been done to explore the nature of the subjective complaint and it’s impact on the activities of daily living.

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Measuring marketing effectiveness is a major challenge for marketing academics and practitioners. An investigation that uses dependence analysis to examine the link between objective marketing instruments and subjective customer perceptions of them is missing from existing approaches. In examining this link, the present article redresses this deficit. A conceptual model is developed in order to structure and explain the effects of instruments on perceptions for 3 marketing instrument categories (value, relationship, and brand). The links are analyzed in an empirical study with bank customers. Instruments are measured by using objective internal data. Perceptions are measured based on a customer survey. The relationships between instruments and perceptions are examined using regression analysis. Most of the effects of instruments on perceptions are significant, signaling that the activities conducted are perceived as intended. In particular, some interesting results become evident, such as the negative effect on relationship perceptions of follow-up calls subsequent to direct mail services.