Explicitly Dependent Events

Multiple failures may be either independent or dependent. Two events are said to be independent if the occurrence of one does not effect the likelihood of the other, otherwise the events are said to be dependent. Most important severe accidents are expected to include events that are at least partially dependent, due to common underlying causes of failure or interactions among systems. Depeiident failures defeat the redundancy or diversity of plant systems that provide key functions such as coolant injection. The term system interaction is used to describe dependent failures that involve or affect more than one plant system. Examples of actual accidents that illustrate various types and modes of failure are presented in Section 2.3 and Appendices 2A and 2B. Dependent failures can be divided into three categories explicitly dependent events, conunon cause failures, and subtle failures. The distinctions between these categories are based on the manner in which the impact of the dependent events are (or are not) treated in risk assessments (Section 2.6). The following subsections describe these three categories of dependent failures in more detail. 

In addition to the explicit dependencies noted above, other dependencies are included by accounting for common cause events. 

Development of laser technology over the last decade or so has permitted spectroscopy to probe short-time events. Instead of having to resort to the study of reactants and products and their energetics and shuctures, one is now able to follow reactants as they travel toward products. Fast pulsed lasers provide snapshots of entire molecular processes [5] demanding similar capabilities of the theory. Thus, explicitly time-dependent methods become suitable theoretical tools. 

Practitioners of SELF explicitly include the dependencies either in the event trees or in the fault trees. Examples of the LESF method that have been examined, treat major dependencies by the definition of degraded states and reevaluate the systems and event trees for the assumed degraded state as well as for the probability of being in that state. Mathematically this is very effective but the dependency coupling is not as pictorial as the SELF method. 

Declarative memory, also termed explicit memory, is memory of places, events, facts and people, and is dependent on the temporal lobe system. Retrieval of these memories requires conscious recollection. This type of memory tends to form easily and be forgotten easily. 

Waller factor because it depends on the transient character of the scattering event, whereas the usual Debye-Waller factor involves only the overall momentum transfer. It is given explicitly [96] by... 

At the heart of the mode coupling theory of liquids is the assumption that a separation of time scale exists between different dynamical events. While the time scale separation between the fast collisional events and the slower collective relaxation is explicitly exploited in the formulation of the theory, there is also an underlying assumption of the separation of length scales between different relaxation modes. Much of the success of MCT depends on the validity of this separation of length and time scales. 

Interactions that involve carbohydrate structures are important in many biological events, including cell adhesion, apoptosis, and immune responses. Their interactions with proteins are normally weak in affinity and traditional techniques may be difficult to use. SPR detection can therefore be favorably utilized for these studies and the need for such analytical methods is expected to grow within the emerging field of glycomics. However, immobihzation of carbohydrates may be a challenge, depending on the explicit nature of the substance. 

Once a reaction mechanism consisting of a sequence of individual elementary reactions has been proposed it is possible to develop rate equations, which predict the dependence of the observed reaction rate on concentration. The principle of mass action, which states the rate at which an elementary reaction takes place is proportional to the concentration of each chemical species participating in the molecular event, is used to write differential rate equations for each elementary reaction in the proposed reaction mechanism. The goal is then to obtain explicit functions of time, which are referred to as integrated rate laws, from these differential rate equations. For simple cases, analytical solutions are readily obtained. Complex sets of elementary reactions may require numerical solutions. 

The kind of modelling of auxiliary processes depends on their structure and importance for the entire system. Often auxiliary processes are modelled on an aggregated level as (global) environmental variables affecting the attributes (such as capacities) of processors. Such processes are often not modelled explicitly by means of processors or flows but rather as (environmental) events which are ruled by stochastic processes. 

Most well-managed projects have embedded within than a series of gates or milestones. These events usually have defined inputs and outputs with explicit expectations that certain materials and decisions will have been completed by that point. The gates are included in the project plan - a document owned by the project manager. It is into these gates that the output from the CRM analysis will feed. In this way the CRM project team is tasked with producing a clear set of deliverables at specific points in the project - formally agreed material which other workstreams will consume and utilise in their own work. These dependencies are important to define at the start of a project so that if timescales are unexpectedly drawn out the impact on other stakeholders can be quickly ascertained. 

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