Sökning: "Proportional Hazards"

Visar resultat 11 - 15 av 76 avhandlingar innehållade orden Proportional Hazards.

  1. 11. On efficient use of censored data and covariate factors in survival analysis and maintenance scheduling

    Författare :Ulf Westberg; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kvalitetsteknik; Quality Technology and Management;

    Sammanfattning : This thesis deals with survival analysis and maintenance scheduling, two important issues to achieve efficient use of different production systems. In survival analysis of failure time data, the survival function and the cumulative hazard function are important reliability characteristics. LÄS MER

  3. 12. Some problems on the selection of a condition based maintenance technique for mechanical systems

    Författare :Basim Al-Najjar; Bo Bergman; Linköpings univeristet; []
    Nyckelord :Terotechnology; Systemekonomi;

    Sammanfattning : In the first paper we focused mainly on establishing a sequential method for the selection of a maintenance technique for mechanical systems. The selection problem is studied for the components having considerable consequences and a non-negligible failure intensity. LÄS MER

  4. 13. Topics on mathematical statistics for medical applications : summary measures and exact simulation of diffusions

    Författare :Celia García-Pareja; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : The first part of this thesis deals with exact simulation of multidimensional diffusion processes. The main contribution is the development of an exact rejection algorithm for sampling coupled Wright-Fisher diffusions. The algorithm’s output provides a skeleton from the diffusion sampled at a random number of time points. LÄS MER

  5. 14. Perforations of the Upper Gastro-Intestinal Tract

    Författare :Michael Hermansson; Lund Kirurgi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; orthopaedics; Prognostic factors; Incidence; Surgery; Diagnostic methods; Proton pump inhibitors; NSAID; Peptic ulcer perforation; Esophageal perforation; traumatology; Kirurgi; ortopedi; traumatologi;

    Sammanfattning : Material and methods: In all, 237 consecutive patients with a perforated peptic ulcer admitted from 1974-1992 and 125 consecutive patients with an oesophageal perforation admitted from 1970-2006 to Lund University hospital were studied retrospectively. Prognostic factors were evaluated using the Cox proportional hazards model. LÄS MER

  7. 15. Prenatal metabolic risks for offspring neurodevelopmental and psychiatric disorders

    Författare :Linghua Kong; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Prenatal metabolic disturbances have been reported to increase the risk for offspring adverse outcomes. However, the joint (i.e. LÄS MER