1,818 research outputs found

    Building Information Modeling (BIM) for Project Value: Quantity Take-Off of Building Frame Approach

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    Purpose - Under today's increasingly complex and large-scale construction environment, building information modeling (BIM) is being recognized as an effective and dominant project management tool. To demonstrate the practical benefits of BIM application, we focused on the quantity take- off (QTO) of a building frame by BIM modeling because accurate cost management is now seen as a critical factor for project value. Design/methodology/approach - QTO is the systematic breakdown of a project into units of work in order to evaluate the cost and time needed to complete a project. We analyze the traditional manual-based approach and the BIM-based approach to find the most practical method, and then examine comparative data from actual case projects. Particularly, a direct comparison of the QTO of building frames between two approaches reveals the accuracy and availableness of the both approaches respectively. Findings - As a result, the BIM-based approach shows higher QTO accuracy (95%) than the manual-based approach (less than 89%). BIM also has other advantages such as allowing partial calculation, re-calculation, and design changes during production stage. Moreover, because design changes are calculated automatically by the BIM operation, drawing omissions and cost estimation errors can be reduced significantly. Originality/value - Thus, project value can be improved by the application of BIM for cases in which all the available cost management information is handled and reproduced by different project participants

    Performance comparison of point and spatial access methods

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    In the past few years a large number of multidimensional point access methods, also called multiattribute index structures, has been suggested, all of them claiming good performance. Since no performance comparison of these structures under arbitrary (strongly correlated nonuniform, short "ugly") data distributions and under various types of queries has been performed, database researchers and designers were hesitant to use any of these new point access methods. As shown in a recent paper, such point access methods are not only important in traditional database applications. In new applications such as CAD/CIM and geographic or environmental information systems, access methods for spatial objects are needed. As recently shown such access methods are based on point access methods in terms of functionality and performance. Our performance comparison naturally consists of two parts. In part I we w i l l compare multidimensional point access methods, whereas in part I I spatial access methods for rectangles will be compared. In part I we present a survey and classification of existing point access methods. Then we carefully select the following four methods for implementation and performance comparison under seven different data files (distributions) and various types of queries: the 2-level grid file, the BANG file, the hB-tree and a new scheme, called the BUDDY hash tree. We were surprised to see one method to be the clear winner which was the BUDDY hash tree. It exhibits an at least 20 % better average performance than its competitors and is robust under ugly data and queries. In part I I we compare spatial access methods for rectangles. After presenting a survey and classification of existing spatial access methods we carefully selected the following four methods for implementation and performance comparison under six different data files (distributions) and various types of queries: the R-tree, the BANG file, PLOP hashing and the BUDDY hash tree. The result presented two winners: the BANG file and the BUDDY hash tree. This comparison is a first step towards a standardized testbed or benchmark. We offer our data and query files to each designer of a new point or spatial access method such that he can run his implementation in our testbed

    Barriers to specialist palliative care in interstitial lung disease: a systematic review

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    Background: Current guidelines recommend palliative care based on individual needs for patients with idiopathic pulmonary fibrosis. However, patients with interstitial lung disease (ILD) are less likely to receive specialist palliative care services compared with patients with malignant disease. The aim of this review is to summarise recent studies addressing barriers to referring patients to specialist palliative care services. Methods: PubMed, Embase, Medline and Web of Science were reviewed to identify relevant publications. Studies were selected if they examined the frequency of specialist palliative care referral and/or addressed issues surrounding access to palliative care services for patients with ILD. Results: Ten studies with a total of 4073 people with ILD, 27 caregivers and 18 healthcare professionals were selected and analysed. Frequency of palliative care referrals ranged from 0% to 38%. Delay in palliative care referrals and end-of-life decisions, patients' fear of talking about the future, prognostic uncertainty and confusion about the roles of palliative care were identified as barriers to accessing palliative care services. Conclusion: Further research should concentrate on the early identification of patients who need specialist palliative care possibly with establishment of criteria to trigger referral ensuring that referrals are also based on patient's needs

    Women, but not men, have prolonged QT interval if depressed after an acute coronary syndrome

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    Aims Depression is a mortality risk marker for acute coronary syndrome (ACS) patients. We hypothesized that the QT interval, a predictor for risk of sudden cardiac death, was related to depressive symptoms in ACS. Methods and results We performed an analysis of admission electrocardiograms from hospitalized patients with unstable angina or non-ST elevation myocardial infarction from two prospective observational studies of depression in ACS. Depressive symptoms were assessed with the Beck Depression Inventory (BDI), and depression was defined as BDI score ā‰„10, compared with <5. Patients with QRS duration ā‰„120 ms and/or who were prescribed antidepressants were excluded. QT intervals were adjusted for heart rate by two methods. Our analyses included 243 men (40.0% with BDI ā‰„10) and 139 women (62.0% with BDI ā‰„ 10). Among women, average QT corrected by Fridericia's method (QTcF) was 435.4 Ā± 26.6 ms in the depressed group, vs. 408.6 Ā± 24.3 ms in the non-depressed group (P< 0.01). However, among men, average QTcF was not significantly different between the depressed and non-depressed groups (415.4 Ā± 23.6 vs. 412.0 Ā± 25.8 ms, P= 0.29). In multivariable analyses that included hypertension, diabetes, ACS type, left ventricular ejection fraction <0.40, and use of QT-prolonging medication, there was a statistically significant interaction between depressive symptoms and gender (P< 0.001). Conclusions In this ACS sample, prolongation of the QT interval was associated with depressive symptoms in women, but not in men. Further investigation of the mechanism of the relationship between depression and abnormal cardiac repolarization, particularly in women, is warranted to develop treatment strategies

    Global Psychological Distress and Risk of Atrial Fibrillation Among Women: The Women's Health Study

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    Background Symptoms of psychological distress and depression have been associated with risk of ventricular arrhythmias and sudden cardiac death. Their relationship with atrial arrhythmias, however, is less well studied. Methods and Results We sought to assess the long-term relations between psychological distress and risk of atrial fibrillation (AF) in the Women's Health Study of female health professionals. We measured psychological symptoms with the Mental Health Inventory-5. Incident AF was assessed annually and verified through medical records. Among 30 746 women without history of cardiovascular disease or AF, 771 cases of AF occurred during a median follow-up of 125 months (interquartile range, 117ā€“130 months). Global psychological distress was not associated with AF risk in age-stratified (P=0.61 for linear trend) or multivariable proportional-hazards models that included antidepressant use (P=0.34). A proxy measure for depression, consisting of Mental Health Inventory-5 score <53, antidepressant use, or both, was also not associated with AF risk in multivariable models (hazard ratio=0.99; 95% confidence interval, 0.78ā€“1.25; P=0.93). In post hoc analyses of individual symptoms from the Mental Health Inventory-5, positive affect, ā€œfeeling happy some/a good bit of the time,ā€ was associated with reduced risk of AF (hazard ratio=0.69; 95% confidence interval, 0.49ā€“0.99; P=0.04); other depressive and anxious symptoms were not. Conclusions In this prospective study of women without known cardiovascular disease, global psychological distress and specific depressive symptoms were unrelated to AF risk
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