Guaranteeing manufacturability of CSG operations

\u3cp\u3eThe paper deals with the integration of design, process planning and manufacturing using Constructive Solid Geometry (CSG) design operations. This integration is achieved by mapping CSG design operations onto manufacturing operations. The mapping is realised such that the manufacturability of the current design can be guaranteed while designing and that a right-first-time production can be realised. Especially the mapping of the CSG operator unite two solids onto the material removal manufacturing technique milling will be dealt with extensively in this paper. The chosen approach is described and explained using an example.\u3c/p\u3

An efficient automatic tool path generator for 2 1/2D free-form pockets

\u3cp\u3eThis paper describes an efficient tool path generator, capable of automatically generating the NC code needed to manufacture arbitrarily shaped pockets with constant depth. The pockets are defined by contours consisting of line-segments and arcs, and may contain islands of unremoved material (also defined by contours of line-segments and arcs). The algorithm used to construct the contour parallel tool path is based on Voronoi diagrams and has an O(n log(n)) complexity, where n denotes the number of contour-segments defining the pocket's boundary.\u3c/p\u3

A relation-based product model suited for integrating design and manufacturing

In this paper a model of the design process is proposed, based on manufacturable design transformations. The product model enables manufacturability checking while designing. The model is based on relations between geometrical entities, with a tolerance model as an inseparable part. When performing for instance assembly analysis, creating numerical code for a machining centre, or command code for a Co-ordinate Measuring Machine, the product description is interpreted for implications in those specific applications. The authors demonstrate a method to reason with tolerances in several stages in design and manufacturing. A typical example is used to illustrate the method

Prevalence, risk factors, and optimal way to determine overweight, obesity, and morbid obesity in the first Dutch cohort of 2338 long-term survivors of childhood cancer:a DCCSS-LATER study

BackgroundOverweight and obesity are common challenges among childhood cancer survivors. Overweight may be disguised, as survivors can have normal weight but high fat percentage (fat%) on dual-energy X-ray absorptiometry (DXA). We aimed to assess prevalence, identify determinants and biomarkers, and assess which method captures overweight best, in a nationwide cohort.MethodsThe prevalence of overweight and obesity, primarily defined by body mass index (BMI), was assessed in the DCCSS-LATER cohort of adult survivors treated from 1963-2002, with the LifeLines cohort as reference. The associations between risk factors and overweight metrics were investigated using logistic regression. Additional overweight metrics included DXA fat%, waist circumference (WC), waist/hip ratio (WHR), waist/height ratio (WHtR), and high-molecular-weight (HMW) adiponectin.ResultsA total of 2338 (mean age 35.5 years, follow-up 28.3 years) survivors participated. The overweight prevalence was 46.3% in men and 44.3% in women (obesity 11.2% and 15.9%, morbid obesity 2.4% and 5.4%), with highest rates among brain tumor survivors. Compared to controls, there was no overall increased overweight rate, but this was higher in women > 50 years, morbid obesity in men > 50 years. Overweight at cancer diagnosis (adjusted odds ratio [aOR] = 3.83, 95% CI 2.19-6.69), cranial radiotherapy (aOR = 3.21, 95% CI 1.99-5.18), and growth hormone deficiency (separate model, aOR = 1.61, 95% CI 1.00-2.59) were associated with overweight. Using BMI, WC, WHR, and WHtR, overweight prevalence was similar. Low HMW adiponectin, present in only 4.5% of survivors, was an insensitive overweight marker. Dual-energy X-ray absorptiometry–based classification identified overweight in an additional 30%, particularly after abdominal radiotherapy, total body irradiation, anthracyclines, and platinum.ConclusionsOverweight occurs in almost half of long-term survivors. There was no overall increased incidence of overweight compared to controls. We identified factors associated with overweight, as well as subgroups of survivors in whom DXA can more reliably assess overweight