JanKees van der Poel

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Automatic face recognition is a challenging problem, since human faces have a complex pattern. This paper presents a technique for recognition of frontal human faces on gray scale images. In this technique, the distance between the Discrete Cosine Transform (DCT) of the face under evaluation and all the DCTs of the faces database are computed. The faces(More)
We present our experience with a new sensitive in vitro method for the study of the immune response to hepatitis B surface antigen (HBsAg). This immunoenzymatic technique, called spot-ELISA, detects specific immunoglobulin production (e.g. IgG- or IgM-anti-HBs) by stimulated individual B cells in vitro. We have studied the immune response against HBsAg by(More)
This paper presents a face recognition method based on Discrete Cosine Transform (DCT) coefficient's selection. Without a normalization phase, the proposed method uses, in its feature selection stage, a technique based only on the DCT coefficients amplitudes. Three coefficient selection criterions were analyzed: the first one is the average of the(More)
This work presents a new multiscale, curvature-based shape representation technique for planar curves. One limitation of the well-known curvature scale space (CSS) method is that it uses only curvature zero-crossings to characterize shapes and thus there is no CSS descriptor for convex shapes. The proposed method, on the other hand, uses(More)
Acute and chronic side-effects have been reported during topical treatment of mycosis fungoides with nitrogen mustard (HN2). In order to estimate the risk for the nurse applying topical HN2, the concentration of HN2 in the air during treatment was measured. Air samples were obtained before, and during the 20-min treatment period close to the nurse and(More)
Loss of protective anti-HBs levels (less than 10 IU/l) was noted in 5 (13%) of 38 well documented healthy responders to hepatitis B vaccine 30 months after completing the initial standard vaccination series. Revaccination with a single booster injection of 20 micrograms hepatitis B vaccine intramuscularly resulted in anti-HBs levels well above those(More)
Among 831 healthy hospital employees vaccinated in accordance with a standard hepatitis B vaccination schedule (three doses of 20 micrograms i.m.), we found 38 (4.6%) hypo- and non-responders with an anti-HBs level less than 10 IU/l. Additional vaccinations with up to three standard doses of hepatitis B vaccine were given to 26 individuals, nine of whom(More)
Methods and techniques for data compression have been used for pattern recognition, including automatic text classification. The performance of the Prediction by Partial Matching (PPM) as a text classifier has already been proofed by many works, including authorship attribution for Portuguese texts. Classes involved in classification process may not be(More)