From e797ce5082cba946c54150cae80e63827c05e40d Mon Sep 17 00:00:00 2001 From: Robin Clark Date: Thu, 21 Jun 2012 20:48:27 +0100 Subject: [PATCH] JMC proof read --- submission_thesis/CH4_FMMD/copy.tex | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/submission_thesis/CH4_FMMD/copy.tex b/submission_thesis/CH4_FMMD/copy.tex index d2b7f85..123bd2d 100644 --- a/submission_thesis/CH4_FMMD/copy.tex +++ b/submission_thesis/CH4_FMMD/copy.tex @@ -481,6 +481,7 @@ defined by $ G_v = 1 + \frac{R2}{R1} $ at the output. As the resistors work to provide a specific function, that of a potential divider, we can treat them as a collection of components with a specific functionality---which can be termed a `{\fg}'. This {\fg} has two members, $R1$ and $R2$. +% Using the EN298 specification for resistor failure~\cite{en298}[App.A], we can assign failure modes of $OPEN$ and $SHORT$ to the resistors individually (assignment of failure modes is discussed in more detail in section~\ref{sec:resistorfm}). @@ -502,7 +503,7 @@ We represent a resistor and its failure modes as a directed acyclic graph (DAG) \path (R) edge (RSHORT); \path (R) edge (ROPEN); \end{tikzpicture} - \caption{DAG representing a resistor and its failure modes} + \caption{DAG representing a resistor and its failure modes.} \label{fig:rdag} \end{figure} @@ -521,7 +522,7 @@ Each {\fc} is analysed to determine the `symptom' of the potential dividers' operation. For instance if resistor $R_1$ were to become open, then the potential~divider would not be grounded and the voltage output from it would float high (+ve). -This would mean the symptom of the failed potential divider would be voltage high output.%We can now consider the {\fg} +This would mean the symptom of the failed potential divider would be voltage high output. %We can now consider the {\fg} %as a component in its own right, and its symptoms as its failure modes. { \small @@ -998,7 +999,7 @@ Failure Scenario & A single failure mode (or a combination), used to \subsection{Parts, Components and Base Components.} -A component is anything we use to build %a product or +A component is anything we use to build a %a product or system. It could be something %quite complicated like an %integrated @@ -1023,7 +1024,7 @@ and say that we want to define an atomic entity. % used as a building block. %The term component, in American English, can mean a building block or a part. %In British-English a component generally is given to mean the definition for part above. We define {\bc} to be the lowest level---or entities we begin with in our analysis---of component that we use as a building block. -This is a choice made by the analyst, often guided by the standards to which the analysis is being performed to. +This is a choice made by the analyst, often guided by the standards to which the analysis is being performed. % to. % Both op-amps and transistors have published statistical failure rates and yet an op-amp is constructed from transistors. % @@ -1041,7 +1042,7 @@ to which we are approving/analysing a system. %% FUCKING STEREO SUB_SYSTEM EXAMPLE, THE FUCKING CHILDRENS SECTION -\subsection{definition of terms: sound system example.} +\subsection{Definition of terms: sound system example.} %000000elpful here to define the terms, `system', `functional~group', `component', `base~component', `symptom' and `derived~component/sub-system'. %These are listed in table~\ref{tab:symexdef}. @@ -1125,7 +1126,7 @@ the symptoms of failure of the {\fg} are the failure modes of this new `{\dc}'. Electrical components have data-sheets associated with them. The data sheets supply detailed information on the component as supplied by the manufacturer. % -Because they are design related they rarely rarely show %clearly detail the +Because they are design related they rarely show %clearly detail the failure modes of the component, with environmental factors and MTTF~\cite{sccs}[p.165] statistics. Given the growing usage of FMEA/FMEDA in industry this may change. Currently, failure mode information is generally only available for generic component types~\cite{mil1991, fmd91}.