viscosity: Viscosity of resin over time

Description Usage Format Details Source Examples

Description

In an experimental setting the viscosity of resin was measured over time to asses the curing process depending on 5 binary factors (low-high).

Usage

1
data("viscosity")

Format

A data list with 64 observations on the following 7 variables.

visAll

viscosity measures over all available time points

timeAll

time points of viscosity measures

T_C

temperature of tools

T_A

temperature of resin

T_B

temperature of curing agent

rspeed

rotational speed

mflow

mass flow

Details

The aim is to determine factors that affect the curing process in the mold. The desired viscosity-curve has low values in the beginning followed by a sharp increase. Due to technical reasons the measuring method of the rheometer has to be changed in a certain range of viscosity. The first observations are measured by rotation of a blade giving observations every two seconds, the later observations are measured through oscillation of a blade giving observations every ten seconds. In the later observations the resin is quite hard so the measurements should be interpreted as a qualitative measure of hardening.

Source

Wolfgang Raffelt, Technical University of Munich, Institute for Carbon Composites

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
 data("viscosity", package = "FDboost")
 ## set time-interval that should be modeled
 interval <- "101"

 ## model time until "interval" and take log() of viscosity
 end <- which(viscosity$timeAll==as.numeric(interval))
 viscosity$vis <- log(viscosity$visAll[,1:end])
 viscosity$time <- viscosity$timeAll[1:end]
 # with(viscosity, funplot(time, vis, pch=16, cex=0.2))

 ## fit median regression model with 100 boosting iterations,
 ## step-length 0.4 and smooth time-specific offset
 ## the factors are in effect coding -1, 1 for the levels
 mod <- FDboost(vis ~ 1 + bols(T_C, contrasts.arg = "contr.sum", intercept=FALSE)
                + bols(T_A, contrasts.arg = "contr.sum", intercept=FALSE),
                timeformula=~bbs(time, lambda=100),
                numInt="equal", family=QuantReg(),
                offset=NULL, offset_control = o_control(k_min = 9),
                data=viscosity, control=boost_control(mstop = 100, nu = 0.4))
 summary(mod)

FDboost documentation built on May 19, 2017, 9:54 p.m.

Search within the FDboost package
Search all R packages, documentation and source code