Sökning: "Proportionality assumption"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Proportionality assumption.
1. Essays on the Assumption of Proportional Hazards in Cox Regression
Sammanfattning : This thesis consists of four papers about the assumption of proportional hazards for the Cox model in survival analysis. The first paper compares the hazard ratio estimated from the Cox model to an exact calculation of the geometric average of the hazard ratio when the underlying assumption of proportional hazards is false, i.e. LÄS MER
2. Democracy and the Common Good : A Study of the Weighted Majority Rule
Sammanfattning : In this study I analyse the performance of a democratic decision-making rule: the weighted majority rule. It assigns to each voter a number of votes that is proportional to her stakes in the decision. LÄS MER
3. Essays on Econometric Theory
Sammanfattning : This dissertation contains a variety of contributions to econometric theory. Broadly speaking, econometrics may be categorized depending on what type of data is being analyzed, the two main categories being time series data and cross sectional data. A third category is panel data, combining cross sectional data observed over time. LÄS MER
4. Fault detection and model quality estimation using mixed integer linear programming
Sammanfattning : Robustness is a necessary property of a control system in an industrial environment, due to changes of the process such as changes of material quality, aging of equipment, replacing of instrument, manual operation (e.g. a valve that is opened or closed) etc. LÄS MER
5. On efficient use of censored data and covariate factors in survival analysis and maintenance scheduling
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