60 resultados para Recursive Partitioning and Regression Trees (RPART)


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Cost management includes planning and control, and constructability1 and prefabrication construction are two main design economics factors for early cost planning decision. Despite the fact that constructability and prefabrication have been considered in design and cost planning, there is no guarantee if the intention meets the expectation. This requires on-going control during construction stage. In fact, prefabrication construction has been encouraged for some years, application is not always positive. One of the reasons is its constructability. This paper investigates the appropriate research methodology to determine how design for prefabrication and constructability will contribute to cost planning through control and review during construction stage. Through a study of an Australian residential project using prefabrication in structural concrete, internal partitioning and internal fit-out, this research concludes that case study is a viable choice. Prefabrication construction does provide a positive impact on the major project objectives: time, cost and quality. Cost reduction is due to saving in time related preliminaries as a direct result of time reduction of onsite activities whilst quality is ensured due to better control of prefabricated components inside the factories. However, it can only be achieved after considering constructability: suitable materials choice, design for available skills, use of available plant, and clear communication. The keys are through plan at design phase and control in construction stage.

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In this brief, a hybrid model combining the fuzzy min-max (FMM) neural network and the classification and regression tree (CART) for online motor detection and diagnosis tasks is described. The hybrid model, known as FMM-CART, exploits the advantages of both FMM and CART for undertaking data classification and rule extraction problems. To evaluate the applicability of the proposed FMM-CART model, an evaluation with a benchmark data set pertaining to electrical motor bearing faults is first conducted. The results obtained are equivalent to those reported in the literature. Then, a laboratory experiment for detecting and diagnosing eccentricity faults in an induction motor is performed. In addition to producing accurate results, useful rules in the form of a decision tree are extracted to provide explanation and justification for the predictions from FMM-CART. The experimental outcome positively shows the potential of FMM-CART in undertaking online motor fault detection and diagnosis tasks.

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 Putrajaya is a model city planned with concepts of a "city in the garden" and an "intelligent city" in the tropics. This study presents the behaviour of the surface temperature and the heat island effect of Putrajaya. Findings show that heat island intensity is 2 °C on average at nighttime and negligible at daytime. But high surface temperature values were recorded at the main boulevard due to direct solar radiation incident, street orientation in the direction of northeast and southwest and low building height-to-street width ratio. Buildings facing each other had cooling effect on surfaces during the morning and evening hours; conversely, they had a warming effect at noon. Clustered trees along the street are effective in reducing the surface temperature compared to scattered and isolated trees. Surface temperature of built up areas was highest at noon, while walls and sidewalks facing northwest were hottest later in the day. Walls and sidewalks that face northwest were warmer than those that face southeast. The surface temperatures of the horizontal street surfaces and of vertical façades are at acceptable levels relative to the surface temperature of similar surfaces in mature cities in subtropical, temperate and Mediterranean climates. © 2014 Springer-Verlag Wien.

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To identify disparities-using recursive partitioning (RP)-in early survival for children with leukemias treated in Argentina, and to depict the main characteristics of the most vulnerable groups.

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In this paper, a hybrid online learning model that combines the fuzzy min-max (FMM) neural network and the Classification and Regression Tree (CART) for motor fault detection and diagnosis tasks is described. The hybrid model, known as FMM-CART, incorporates the advantages of both FMM and CART for undertaking data classification (with FMM) and rule extraction (with CART) problems. In particular, the CART model is enhanced with an importance predictor-based feature selection measure. To evaluate the effectiveness of the proposed online FMM-CART model, a series of experiments using publicly available data sets containing motor bearing faults is first conducted. The results (primarily prediction accuracy and model complexity) are analyzed and compared with those reported in the literature. Then, an experimental study on detecting imbalanced voltage supply of an induction motor using a laboratory-scale test rig is performed. In addition to producing accurate results, a set of rules in the form of a decision tree is extracted from FMM-CART to provide explanations for its predictions. The results positively demonstrate the usefulness of FMM-CART with online learning capabilities in tackling real-world motor fault detection and diagnosis tasks. © 2014 Springer Science+Business Media New York.

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In this paper, a hybrid model consisting of the fuzzy ARTMAP (FAM) neural network and the classification and regression tree (CART) is formulated. FAM is useful for tackling the stability–plasticity dilemma pertaining to data-based learning systems, while CART is useful for depicting its learned knowledge explicitly in a tree structure. By combining the benefits of both models, FAM–CART is capable of learning data samples stably and, at the same time, explaining its predictions with a set of decision rules. In other words, FAM–CART possesses two important properties of an intelligent system, i.e., learning in a stable manner (by overcoming the stability–plasticity dilemma) and extracting useful explanatory rules (by overcoming the opaqueness issue). To evaluate the usefulness of FAM–CART, six benchmark medical data sets from the UCI repository of machine learning and a real-world medical data classification problem are used for evaluation. For performance comparison, a number of performance metrics which include accuracy, specificity, sensitivity, and the area under the receiver operation characteristic curve are computed. The results are quantified with statistical indicators and compared with those reported in the literature. The outcomes positively indicate that FAM–CART is effective for undertaking data classification tasks. In addition to producing good results, it provides justifications of the predictions in the form of a decision tree so that domain users can easily understand the predictions, therefore making it a useful decision support tool.

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Introduction: While the risk of adverse events following surgery has been identified, the impact of nursing care on early detection of these events is not well established. A systematic review of the evidence and an expert consensus study in post-anaesthetic care identified essential criteria for nursing assessment of patient readiness for discharge from the Post-Anaesthetic Care Unit. These criteria were included in a new nursing assessment tool, the Post-Anaesthetic Care Tool (PACT), and incorporated into the post-anaesthetic documentation at a large health service. The aim of this study is to test the clinical reliability of the PACT and evaluate whether use of PACT will i) enhance the recognition and response to patients at risk of deterioration in PACU; ii) improve documentation for handover from PACU nurse to ward nurse; iii) result in improved patient outcomes; and iv) reduce health care costs.

Methods and analysis
: A prospective, non-randomised, pre- and post-implementation design comparing: (i) patients (n=750) who have surgery prior to the implementation of the PACT and (ii) patients (n=750) who have surgery after PACT. The study will examine the use of the tool through the observation of patient care and nursing handover. Patient outcomes and cost effectiveness will be determined from health service data and medical record audit. Descriptive statistics will be used to describe the sample and compare the two patient groups (pre- and post-intervention). Differences in patient outcomes between the two groups will be compared using the Cochran-Mantel-Haenszel test and regression analyses and reported as odds ratios with the corresponding 95% confidence intervals.

Conclusion: This study will test the clinical reliability and cost-effectiveness of the PACT. It is hypothesised that the PACT will enable nurses to recognise and respond to patients at risk of deterioration, improve handover to ward nurses, improve patient outcomes, and reduce health care costs.

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Coarse woody debris (CWD) is a common structural component of terrestrial ecosystems, and provides important habitat for biota. Fires modify the distribution of CWD, both spatially and temporally. Changes in fire regimes, such as those arising from prescribed burning and changing climatic conditions, make it critical to understand the response of this resource to fire. We created a conceptual model of the effects of fire on logs and dead trees in topographically diverse forests in which trees often survive severe fire. We then surveyed paired sites, in a damp gully and adjacent drier slope, ~3.5. years after a large wildfire in south-eastern Australia. Sites were stratified by fire severity (unburnt, understorey burnt and severely burnt), and fire history (burnt ≤3. years or ≥20. years prior to the wildfire). Both components of the fire regime influenced CWD availability in gullies. Severe wildfire and fire history ≤3. years reduced the volume of small logs (10-30. cm diameter) in gullies, while severe wildfire increased the number of large dead trees in gullies. CWD on slopes was not affected by fire severity or history at ~3.5. years post-fire. Log volumes on slopes may recover more quickly after wildfire through rapid collapse of branches and trees. Gullies generally supported more logs than slopes, but longer inter-fire intervals in gullies may allow fuel loads to accumulate and lead to comparatively larger fire impacts. Given that fire severity and fire interval are predicted to change in many fire-prone ecosystems in coming decades, this study highlights the importance of understanding the interacting effects of multiple components of the fire regime with landscape structure. In particular, variation in fire interval and fire severity in relation to topographic position will influence the pattern of accumulation of coarse woody debris across the landscape, and therefore the structure and quality of habitats for biota.

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BACKGROUND: Investigating socioeconomic variation in physical activity (PA) and sedentary time is important as it may represent a pathway by which socioeconomic position (SEP) leads to ill health. Findings on the association between children's SEP and objectively assessed PA and/or sedentary time are mixed, and few studies have included international samples.

OBJECTIVE: Examine the associations between maternal education and adolescent's objectively assessed PA and sedentary time.

METHODS: This is an observational study of 12 770 adolescents (10-18 years) pooled from 10 studies from Europe, Australia, Brazil and the USA. Original PA data were collected between 1997 and 2009. The associations between maternal education and accelerometer variables were examined using robust multivariable regression, adjusted for a priori confounders (ie, body mass index, monitor wear time, season, age and sex) and regression coefficients combined across studies using random effects meta-analyses. Analyses were conducted in March 2014.

RESULTS: Adolescents of university educated mothers spent more time sedentary (9.5 min/day, p=0.005) and less time in light activity (10 min/day, p<0.001) compared with adolescents of high school educated mothers. Pooled analysis across two studies from Brazil and Portugal (analysed separately because of the different coding of maternal education) showed that children of higher educated mothers (tertiary vs primary/secondary) spent less time in moderate to vigorous PA (MVPA) (6.6 min/day, p=0.001) and in light PA (39.2 min/day: p<0.001), and more time sedentary (45.9 min/day, p<0.001).

CONCLUSIONS: Across a number of international samples, adolescents of mothers with lower education may not be at a disadvantage in terms of overall objectively measured PA.

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OBJECTIVE: To validate the Meaning in Life Questionnaire (MLQ) in earlier and later older-adulthood, and examine its correlates. METHOD: Participants in earlier (n = 341, M age = 68.5) and later older-adulthood (n = 341, M age = 78.6) completed the MLQ and other measures. Confirmatory multigroup analysis, correlations, and regression models were conducted. RESULTS: A two-factor (presence and search), eight-item model of the MLQ had a good fit and was age-invariant. Presence and search for meaning were largely unrelated. Meaning was associated with life satisfaction, well-being across a range of domains, and psychological resources. Searching for meaning correlated negatively with these variables, but to a lesser degree in later older-adulthood. DISCUSSION: The MLQ is valid in older-adulthood. Meaning in life is psychologically adaptive in older-adulthood. Searching for meaning appears less important, especially in later older-adulthood. Findings are discussed in the context of aging and psychosocial development.

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This work was aimed to study whether the application of ethephon as an abscission agent and mechanical harvest using a trunk shaker have any effect on plant water status, leaf gas exchange, and yield of mandarin and orange trees cultivated under Mediterranean conditions. The experiment was performed from 2008 to 2011 in five commercial orchards where parameters related to the plant water status and leaf gas exchange were measured before the application of ethephon, at harvest time and at different occasions after harvest. In addition, the effects of ethephon dose on yield in the current and subsequent seasons were also evaluated. Results showed that ethephon applications and mechanical harvest did not detrimentally affect plant water status in any of the cultivars studied. Furthermore, either had no effect or had a short temporal decrease effect on leaf gas exchange depending on the cultivar studied although with no consequences for the fruit yield obtained during the current season. Increasing ethephon doses led to fruit yield reductions in the mandarin ‘Orogrande’ trees in subsequent seasons. When trunk-shaker and ethephon applications were combined, however, yields from the late-maturing orange significantly decline in subsequent seasons. Overall, results show that using a trunk shaker is a viable technique to mechanically harvest citrus trees destined to both fresh and industry market and can be considered as an alternative to the traditional manual harvest usually performed under Mediterranean conditions. However, its use cannot be recommended for late-maturing oranges, such as the ‘Navel Lane Late’ in which mature fruit and fruitlets coexist in the tree at the time of harvest.

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OBJECTIVES: Capillary refill time (CRT) has been taught as a rapid indicator of circulatory status. The aim of this study was to define normal CRT in the Australian context and the environmental, patient, and drug factors that influence it.

METHODS: This prospective observational study included healthy adults at hospital clinics, workplaces, universities, and community groups. Volunteer participants provided their age, sex, ethnic group, and use of hypertensive or cardiac medications. Capillary refill time, ambient temperature, and patient temperature were recorded in a standard manner. Data were analyzed using descriptive statistics and regression analyses. The 95th percentile was used to define the upper limit of normal.

RESULTS: One thousand participants were included; 57% were women, 90% were white, and 21% were taking cardiac medications. The median CRT was 1.9 seconds (95th percentile, 3.5 seconds). The CRT increased 3.3% for each additional decade of age. The CRT was also on average 7% lower in men than in women. The CRT decreased by 1.2% per degree-Celsius rise of ambient temperature, independently of patient's temperature, and decreased by 5% for each degree-Celsius rise in patient temperature, independently of ambient temperature. On multivariant analysis, age, sex, ambient temperature, and patient temperature were statistically significant predictors of CRT, but together explain only 8% of the observed variability.

CONCLUSION: Capillary refill time varies with environmental and patient factors, but these account for only a small proportion of the variability observed. Its suitability as a reliable clinical test is doubtful.

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This research is concerned with the mechanical and physical properties of hemp fibre reinforced concrete (HFRC). An experimental program was developed based on the statistical method of fractional factors design. The variables for the experimental study were: (1) mixing method; (2) fibre content by weight; (3) aggregate size; and (4) fibre length. Their effects on the compressive and flexural performance of HFRC composites were investigated. The specific gravity and water absorption ratio of HFRC were also studied. The results indicate that the compressive and flexural properties can be modelled using a simple empirical linear expression based on statistical analysis and regression, and that hemp fibre content (by weight) is the critical factor affecting the compressive and flexural properties of HFRC.

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The conservation of roosting and nesting resources is of critical concern for many hollow-dependent species around the world. We investigated the nest-tree requirements of the threatened brush-tailed phascogale (Phascogale tapoatafa) in a highly cleared agricultural landscape in south-eastern Australia. We documented the physical characteristics of selected nest trees and describe the spatial and temporal patterns of nest-tree use as revealed by radio-tracking. Nine phascogales (seven females, two males) were radio-tracked between March and July 1999 in an area where most woodland habitat is confined to linear strips along roads and streams or small patches and scattered trees in cleared farmland. Female phascogales were monitored for 13–35 days over periods of 5–15 weeks and two males were monitored for 2 and 9 days respectively. A total of 185 nest-tree fixes was collected and all nests occupied by phascogales were in standing trees. Eighty-three nest trees were identified, ranging in diameter at breast height (dbh) from 25 to 171 cm, with a mean dbh for the trees used by each individual phascogale of >80 cm. Phascogales did not discriminate between canopy tree species in selecting nest trees, but showed highly significant selection for trees in the largest size class. All individuals used multiple nest trees, with the seven females occupying an average of 11.4 nest trees from a mean of 25 diurnal locations. The number of nest trees continued to increase throughout the study, suggesting that more would be identified during a longer or more intensive study. Occupied nest trees were located throughout each individual’s home range, highlighting the importance of a continuous spatial distribution of suitable nest trees across the landscape. Nest trees were also located in adjacent farmland up to 225 m from roadside vegetation, demonstrating the value that scattered clumps and even single trees in farmland can have for wildlife conservation.

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The survival of habitat-dependent fauna within agricultural mosaics depends on their ability to occupy remnant habitat patches and move through the modified landscape. In north-west Victoria, Australia, less than 10% of the pre-European extent of Selah Casuarina pauper woodland remains intact due to agricultural development. The White-browed Treecreeper Climacteris affinis, is a small, insectivorous passerine that, in this region, preferentially inhabits Selah woodland. To assess the ability of C. affinis to persist in an agricultural landscape, 30 woodland sites in the Millewa landscape (34°30'S, 141°30'E) were surveyed, and patterns of patch occupancy used to examine the influence of spatial characteristics, landscape context and grazing by stock on the suitability of remnants as C. affinis habitat. Sites occupied by C. affinis were larger and less likely to be grazed by stock than vacant patches. The area-dependency of patch occupancy represents a step-threshold: C. affinis were not detected in remnants with less than 18.5 ha of Selah woodland but above this threshold, density was not correlated with patch area. Measures of patch isolation, the existence of linking linear "corridors" and tree density were not reliable indicators of patch occupancy. The presence of the species in remnants entirely surrounded by agricultural land suggests they are capable of crossing up to 450 m of cultivated land to prospect for habitat. The extensive network of linear vegetation and the numerous small remnants and scattered trees appear to facilitate movements of C. affinis in this landscape. Increasing the size of existing remnants, creating new habitat to expand the area of occupancy and maintaining landscape connectivity are priorities for the long-term management of this threatened species.