Objective: This study developed and evaluated a computer-based method for automating the registration of scanned dental models with 3D reconstructed skulls and segmentation of the temporomandibular joint (TMJ). method...
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Objective: This study developed and evaluated a computer-based method for automating the registration of scanned dental models with 3D reconstructed skulls and segmentation of the temporomandibular joint (TMJ). methods: A dataset comprising 1274 skull models and corresponding scanned dental models was collected. In total, 1066 cases were used for the development of the computer-based method, while 208 cases were used for validation. Performance was evaluated by comparing the automated results with manual registration and segmentation performed by clinicians, using accuracy and completeness metrics (e.g. intersection of union [IoU] and Dice similarity coefficient [DSC]). Results: The automated registration achieved a mean absolute error of 0.35 mm for the maxilla and 0.38 mm for the mandible, and a root mean squared error of 0.46 mm and 0.39 mm, respectively. The automatic TMJ segmentation exhibited an accuracy of 97.48 %, a precision of 97.06 %, a IoU of 95.72 %, DSC of 97.3 %, and a Hausdorff value of 1.87 mm, which were sufficient for clinical application. Conclusion: The proposed method significantly improved the efficiency of orthognathic surgical planning by automating the registration and segmentation processes. The accuracy and precision of the automated results were sufficient for clinical use, reducing the workload on clinicians and facilitating faster and more reliable surgical planning. Clinical significance: The computer-based method streamlines orthognathic surgical planning, enhancing precision and efficiency without compromising clinical accuracy, ultimately improving patient outcomes and reducing the workload of surgeons.
Aims and objectives: This article presents findings from a dietary intervention designed to improve the nutritional knowledge, attitudes, intentions and dietary intake of socially disadvantaged children. Design: Quasi...
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Aims and objectives: This article presents findings from a dietary intervention designed to improve the nutritional knowledge, attitudes, intentions and dietary intake of socially disadvantaged children. Design: Quasi-experimental design. methods: A total of 201 (treatment group n = 106, control n = 95) children completed the questionnaire at pre- and post-test. Data from 99 participants from the treatment group were included at 12-month follow-up. The treatment group received a dual intervention of computer-based and traditional methods for 3 consecutive weeks. Results: The findings show no significant differences in scores of dietary knowledge and intentions between pre- and post-measures in both treatment and control groups. At post-test, however, the treatment group reported a better knowledge score, a significantly higher intention to limit unhealthy food and a more negative attitude towards less healthy food than the control group. The results of the short-term evaluation suggest that only the treatment group showed a significant reduction in unhealthy food consumption and a significant increase in vegetable intake. Nevertheless, at follow-up, these effects were not sustained. Prospectively, however, we found a predictive effect of dietary knowledge and intentions on food intake at follow-up. Conclusion: Given the relatively short-term effects achieved by the intervention, it remains crucial to understand the aspects of short-term interventions that may lead to longer term effects, as well as the mechanisms underlying dietary intake among this group of children.
Forensic firearm examiners compare the features in cartridge cases to provide a judgment addressing the question about their source: do they originate from one and the same or from two different firearms? In this arti...
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Forensic firearm examiners compare the features in cartridge cases to provide a judgment addressing the question about their source: do they originate from one and the same or from two different firearms? In this article, the validity and reliability of these judgments is studied and compared to the outcomes of a computer-based method. The features we looked at were the striation patterns of the firing pin aperture shear marks of four hundred test shots from two hundred Glock pistols, which were compared by a computer-based method. Sixty of the resulting 79,800 comparisons were shown to 77 firearm examiners. They were asked to judge whether the cartridge cases had the same source or a different source, and to indicate the degree of support the evidence provided for those judgments. The results show that the true positive rates (sensitivity) and the true negative rates (specificity) of firearm examiners are quite high. The examiners seem to be slightly less proficient at identifying same-source comparisons correctly, while they outperform the used computer-based method at identifying different-source comparisons. The judged degrees of support by examiners who report likelihood ratios are not well-calibrated. The examiners are overconfident, giving judgments of evidential strength that are too high. The judgments of the examiners and the outcomes of the computer-based method are only moderately correlated. We suggest to implement performance feedback to reduce overconfidence, to improve the calibration of degree of support judgments, and to study the possibility of combining the judgments of examiners and the outcomes of computer-based methods to increase the overall validity. (C) 2019 Elsevier B.V. All rights reserved.
Assembly line balancing (ALE) is an important aspect in the design of many flow line type manufacturing systems which may or may not be assembly oriented. It involves essentially assigning individual tasks into statio...
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Assembly line balancing (ALE) is an important aspect in the design of many flow line type manufacturing systems which may or may not be assembly oriented. It involves essentially assigning individual tasks into stations such that certain constraints are satisfied and some specified objectives achieved. Although this problem has attracted a great deal of research effort over the past forty years, it still remains unsolved. This paper presents a computer-based method for the simple assembly line balancing problem (SALBP). For a given problem, the method makes use of some efficient and systematic search and identification techniques to establish task trees for individual stations and to develop a station tree for multiple solutions. Different from all known existing assembly line balancing methods, this method aims at finding the best possible solutions that lead to the maximum production rate and the minimum station workload variation. The essential and distinct concepts adopted by the method are described in this paper, along with its step-by-step execution procedure and an illustrative example. Since the method does not involve difficult mathematics, many industrial practitioners can easily understand it and appreciate its effectiveness.
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