overloaded FM function to cope with functional groups as well as components
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@ -231,6 +231,41 @@ would have a level of 1.
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% $$ \bowtie ( FG ) \mapsto DerivedComponent $$
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% $$ \bowtie ( FG ) \mapsto DerivedComponent $$
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%
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%
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\subsection{relationships between functional~groups and failure modes}
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Let the set of all possible components be $\mathcal{C}$
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and let the set of all possible failure modes be $\mathcal{F}$.
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We can define a function $FM$
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\begin{equation}
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FM : \mathcal{C} \mapsto \mathcal{P}\mathcal{F}
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\end{equation}
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defined by, where C is a component and F is a set of failure modes.
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$$ FM ( C ) = F $$
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\paragraph{Finding all failure modes within the functional group}
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For FMMD failure mode analysis we need to consider the failure modes
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from all the components in a functional~group as a flat set.
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Consider the components in a functional group to be $C$ indexed by j thus $C_j$.
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Thflat set of failure modes we are after can be found by applying function $FM$ to all the components
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in the functional~group and taking the union of them thus:
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$$ FunctionalGroupAllFailureModes = \bigcup_{j \in \{1...n\}} FM(C_j) $$
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We can actually overload the notation for the function FM
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and define it for the set components within a functional group $FG$ (i.e. where $FG \subset \mathcal{C} $) thus:
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\begin{equation}
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FM : FG \mapsto \mathcal{F}
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\end{equation}
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\section{Unitary State Component Failure Mode sets}
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\section{Unitary State Component Failure Mode sets}
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@ -261,19 +296,19 @@ probability theory\cite{probandstat}.
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Let the set of all possible components to be $\mathcal{C}$
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Let the set of all possible components to be $\mathcal{C}$
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and let the set of all possible failure modes be $\mathcal{F}$.
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and let the set of all possible failure modes be $\mathcal{F}$.
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%
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We can define a function $FM$
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%We can define a function $FM$
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%
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\begin{equation}
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%\begin{equation}
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FM : \mathcal{C} \mapsto \mathcal{F}
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%FM : \mathcal{C} \mapsto \mathcal{F}
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\end{equation}
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%\end{equation}
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%
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defined by
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%defined by
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%
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$$ FM ( C ) = F $$
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%$$ FM ( C ) = F $$
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%
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i.e. take a given component $C$ and return its set of failure modes $F$.
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%i.e. take a given component $C$ and return its set of failure modes $F$.
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%
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\begin{definition}
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\begin{definition}
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We can define a set $\mathcal{U}$ which is a set of sets of failure modes, where
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We can define a set $\mathcal{U}$ which is a set of sets of failure modes, where
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the component failure modes in each of its members are unitary~state.
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the component failure modes in each of its members are unitary~state.
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@ -415,9 +450,9 @@ For example: were we to have a simple functional group with two components R and
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$$FM(R) = \{R_o, R_s\}$$ and $$FM(T) = \{T_o, T_s, T_h\}$$.
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$$FM(R) = \{R_o, R_s\}$$ and $$FM(T) = \{T_o, T_s, T_h\}$$.
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This means that the functional~group $FG=\{R,T\}$ will have a component failure mode set
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This means that the functional~group $FG=\{R,T\}$ will have a component failure mode set
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of $FG_{cfg} = \{R_o, R_s, T_o, T_s, T_h\}$
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of $FM(FG) = \{R_o, R_s, T_o, T_s, T_h\}$
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For a cardinality constrained powerset of 2, because there are 5 error modes ( $|{FG_{cfg}}|=5$),
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For a cardinality constrained powerset of 2, because there are 5 error modes ( $|FM(FG)|=5$),
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applying equation \ref{eqn:ccps} gives :-
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applying equation \ref{eqn:ccps} gives :-
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$$\frac{5!}{1!(5-1)!} + \frac{5!}{2!(5-2)!} = 15$$
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$$\frac{5!}{1!(5-1)!} + \frac{5!}{2!(5-2)!} = 15$$
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@ -431,12 +466,12 @@ For component R there is only one internal component fault that cannot exist
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$R_o \wedge R_s$. As a combination ${2 \choose 2} = 1$. For the component $T$ which has
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$R_o \wedge R_s$. As a combination ${2 \choose 2} = 1$. For the component $T$ which has
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three fault modes ${3 \choose 2} = 3$.
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three fault modes ${3 \choose 2} = 3$.
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Thus for $cc == 2$, under the conditions of unitary state failure modes in the components $R$ and $T$, we must subtract $(3+1)$.
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Thus for $cc == 2$, under the conditions of unitary state failure modes in the components $R$ and $T$, we must subtract $(3+1)$.
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The number of combinations to check is thus 11, $|\mathcal{P}_{2}(FG_{cfg})| = 11$, for this example and this can be verified
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The number of combinations to check is thus 11, $|\mathcal{P}_{2}(FM(FG))| = 11$, for this example and this can be verified
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by listing all the required combinations:
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by listing all the required combinations:
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$$ \mathcal{P}_{2}(FG_{cfg}) = \{
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$$ \mathcal{P}_{2}(FM(FG)) = \{
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\{R_o T_o\}, \{R_o T_s\}, \{R_o T_h\}, \{R_s T_o\}, \{R_s T_s\}, \{R_s T_h\}, \{R_o \}, \{R_s \}, \{T_o \}, \{T_s \}, \{T_h \}
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\{R_o T_o\}, \{R_o T_s\}, \{R_o T_h\}, \{R_s T_o\}, \{R_s T_s\}, \{R_s T_h\}, \{R_o \}, \{R_s \}, \{T_o \}, \{T_s \}, \{T_h \}
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\}
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\}
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$$
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$$
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@ -466,11 +501,11 @@ that are members of the functional group $FG$
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i.e. $ \forall j \in J | C_j \in FG $
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i.e. $ \forall j \in J | C_j \in FG $
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\item Let $|FM({C}_{j})|$
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\item Let $|FM({C}_{j})|$
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indicate the number of mutually exclusive fault modes of each component
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indicate the number of mutually exclusive fault modes of each component
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\item Let $FG_{cfg}$ be the collection of all failure modes
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\item Let $FM(FG)$ be the collection of all failure modes
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from all the components in the functional group.
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from all the components in the functional group.
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\item Let $SU$ be a set of failure modes from the functional group,
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\item Let $SU$ be a set of failure modes from the functional group,
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where all contributing components $C_j$
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where all contributing components $C_j$
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are guaranteed to be `unitary state' i.e. $(SU = FG_{cfg}) \wedge (\forall j \in J | FM(C_j) \in \mathcal{U}) $
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are guaranteed to be `unitary state' i.e. $(SU = FM(FG)) \wedge (\forall j \in J | FM(C_j) \in \mathcal{U}) $
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\end{itemize}
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\end{itemize}
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%}
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%}
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@ -29,7 +29,7 @@ of the relationships between the contours.
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{ %% Introduction
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{ %% Introduction
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\section{Algorithm Purpose}
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\section{Algorithm Purpose}
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This paper discusses a two stage algorithm designed to greatly
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This chapter discusses a two stage algorithm designed to greatly
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reduce the number of Area compare operations required to determine which zones are `available' in an Euler
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reduce the number of Area compare operations required to determine which zones are `available' in an Euler
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diagram.
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diagram.
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