[Mass screening for cervical cancer. Experiences after 25 years of voluntary screening and 2 years of organized screening]. / Masseundersøkelsen for livmorhalskreft. Erfaringer etter 25 år med villscreening og to års organisert screening.

In 1990 the Norwegian Ministry of Health and Social Services initiated an organised screening programme for cervical cancer, the main goal of which is to reduce the incidence of and mortality from cervical cancer in Norway. All women aged between 25-69 years are offered screening every third year. In the first three years of the programme, all voluntary screening was reported to The Cancer Registry of Norway. This showed that a high number of smear tests were carried out on young women, against a low rate of smear tests on older women. Since January 1995 invitations have been sent to all women aged between 25-69 years, where there is no record of a smear test having been done in the last three years. Results so far show that the number of women who have had a smear test done in the last three years is increasing in the older age groups. A total of 2.6 million smears have been recorded. Approximately 90% of the smears were normal, only 1.7% showing signs of dysplasia. All pathological smears will be followed up with a reminder either from the laboratories or The Cancer Registry.

Multivariate autoregressive feature extraction and the recognition of multichannel waveforms.

It is proposed that the autoregressive coefficient matrices appearing in a multivariate autoregressive model fitting may be used for feature extraction purposes in problems concerning recognition of multichannel waveforms. It is demonstrated how the information contained in the autoregressive parameters may be further compressed by applying the ordinary or a modified Karhunen-Loeve expansion. The feature extraction procedures are illustrated on a large data base of seismic wave traces originating from shallow earthquakes and underground nuclear explosions. The results obtained (using a multivariate Gaussian classification algorithm) suggest that the combined autore-gressive/Karhunen-Loeve method has a considerably larger discrimination potential than the more conventional seismic discriminants.