Sommige metodes en toepassings van kwadratiese programmering

Proefskrif (M. Sc.) -- Universiteit van Stellenbosch, 1968.Full text to be digitised and attached to bibliographic record

Ontwikkeling en toepassing van wiskundige programmerings-tegnieke vir besluitneming by voermengselprobleme

Proefskrif (Ph. D.) -- Universiteit van Stellenbosch, 1988.Full text to be digitised and attached to bibliographic record

Affecting patients with work-related problems by educational training of their GPs: a cost-effectiveness study

Contains fulltext : 201908.pdf (publisher's version ) (Open Access

Treatise of digital reconstruction and restauration of lace porcelain

Lace porcelain is a fragile type of ceramics that is used to be in fashion in 19th century Dresden artworks. It is known to break easily while manual repair is nearly impossible. Instead, we considered digital scanning, reconstruction, and 3D printing of the damaged areas towards new digital restauration methodologies. One reference case was used throughout testing the enabling technologies, and the combination of micro CT and polyjet 3D printing proved to be most useful. However, defining a proper workflow are specifically digital modeling of porcelain lace requires complex modelling strategies, especially to make it fit for 3D printing

Work-relatedness of the presented health problem and sickness absence

BACKGROUND: Perception by workers of their health problems as work-related is possibly associated with sickness absence (SA). The aim of this study was to to study the relationship between perceived work-relatedness of health problems and SA among workers who visit their GP, taking the influence of other potential determinants into account and to study the influence of these determinants on SA. Design and setting prospective cohort study in 32 Dutch GP practices. METHODS: A secondary analysis of RCT data among workers, aged 18-63 years, who visited their GP. We measured self-reported SA days in 12 months and high SA (>20 days in 12 months) and compared workers who perceived work-relatedness (WR+) with workers who did not (WR-). With multivariable linear and logistic regression models, we analyzed the influence of age, gender, experienced health, chronic illness, prior SA, number of GP consultations and perceived work ability. RESULTS: We analyzed data of 209 workers, 31% perceived work-relatedness. Geometric mean of SA days was 1.6 (95% CI: 0.9-3.0) for WR+- workers and 1.2 (95% CI: 0.8-1.8) for WR- workers (P = 0.42). Incidence of high SA was 21.5 and 13.3%, respectively (odds ratio 1.79; 95% CI: 0.84-3.84). SA was positively associated with chronic illness, prior SA, low perceived work ability and age over 50. CONCLUSIONS: Perceived work-relatedness was not associated with SA. SA was associated with chronic illness, prior SA, low perceived work ability and age over 50

Conventional CT for the prediction of an involved circumferential resection margin in primary rectal cancer

Purpose: To determine the accuracy of conventional computed tomography (CT) scan in the preoperative prediction of an involved circumferential resection margin (CRM) in primary rectal cancer. Methods: 125 patients with biopsy-proven adenocarcinoma of the rectum underwent CT of the abdomen before undergoing total mesorectal excision. Scans were scored by three observers, differing in experience. The main outcome was yes/no involvement of the CRM. Histology was taken as reference standard. Results: For the most experienced observer, observer A, sensitivity was 46.7% and specificity 92.6%. For observer B, sensitivity was 46.7% and specificity 89.5%. For the least experienced observer C, sensitivity was 43.3% and specificity 92.6%. Inter-observer variability was good between observers A and B (kappa 0.648), B and C (kappa 0.648), and intermediate between A and C (kappa 0.542). Discrepancies occurred in a total of 34 patients; 25 had a CT scan of low technical quality, 10 an anteriorly located distal tumor. Conclusion: Conventional CT scan lacks sensitivity for a clinical use in the preoperative assessment of an involved CRM in primary rectal cancer. Modern multislice spiral CT will probably resolve some of the problems of conventional CT; however, further research is needed to establish its role. Copyright (c) 2007 S. Karger AG, Base