Dependence Diagrams

In a program, each object generally communicates with several others. Drawing a dependency diagram between the classes, you end up with many loops. For example, callbacks such as in an observer pattern result in loops. Simplistically, you may decide that each must know about the other, because it sends it a message (see Figure 7.13). In fact, this program is far more coupled than it need be. Each of these classes does not need to know about the more operations of the other class they are used by other correspondents we ve not shown here. 

Draw dependency diagrams (see Section 7.4, Decoupling with Packages) between operations, classes, packages, and components. Study the package-level dependencies and seek ways to refactor across packages to reduce coupling. 

Fig. 3. Simulations calculated with the PHREEQC geochemical code (Parkhust Appelo 1999) (a) time-dependent diagram for the pH evolution of the Aspo ground water/bentonite interaction (b) time-dependent diagram for the pe evolution of the Aspo groundwater/bentonite interaction. Curves correspond to different initial partial oxygen pressures. Initial calcite and pyrite contents are 0.3 wt% and 0.01 wt% respectively, except for the curve of log/02 = —0.22 where calcite and pyrite contents are 1.4 wt% and 0.3 wt%, respectively, pe calculated stands for the cases where the oxygen fugacity is obtained from the groundwater redox potential (Bruno et at. 1999).

FIGURE 3.11 Schematic frequency-dependence diagram of out-of-phase (y") AC susceptibilities measured for the single-molecule magnet Fe8 for a range of frequencies, indicating the slowing down of spin relaxation at low temperatures. 

In summary, the rules for the construction and subsequent evaluation of diagrams corresponding to matrix elements in the CCSDT model have been given. The adaptation of certain features from time-dependent diagrams, not usually found in time-independent approaches, have been seen to clarify and/or expedite time-independent diagrams. 

Fig. 4. Solidus portion of the pressure-dependent diagram for the PrS, jj-PrSioo system. Phase stability fields are marked as 1-6.

Dependence Diagrams (DD) These are similar to the FTA, but replace the logic gates by paths to show the relationship of the failures. A DD analysis is success oriented and is conducted from the perspective of which failures must not occur to preclude a defined Failure Condition. For more information, see Appendix E in SAE ARP4761. 

Step la This CMA process is performed to verify that AND events (e.g. in the Fault Tree Analysis (FTA) or Dependence Diagrams (DD), or any quahtative probabihty declaration) are truly independent. 

RTC A/DO-254 defines Functional Failure Path (FFP) as the specific set of interdependent circuits that could cause a particular anomalous behaviour in the hardware that implements the function or in the hardware that is dependent upon the function. FFP Analysis (FFPA) is used to iteratively decompose the hardware functions into a hierarchy of subfunction to determine if it will be possible to fulfil completely the objectives of RTCA/DO-254 for each subfunction. If the assurance lifecycle data available or expected to be available is complete, correct and acceptable per the RTCA/DO-254 objectives and guidance, then no further decomposition is necessary. If it is not, then decomposition continues until such a stage as the FFP feasibly maps to one of the Development Assurance methods (and associated data set) as described in the previous section. For FFPs that are not Levels A or B, their interrelationships with the Level A or B FFPs should be evaluated using an F-FMEA, common mode analysis or dependency diagram to ensure that the Level A and B FFPs cannot be adversely impacted by the FFPs which are not Level A or B. 

In our previous work we have developed the tool OpenSESAME (Simple but Extensive, Structured Availability Modeling Environment (Walter Schneeweiss 2005 Walter et al. 2008 Walter 2000)). In OpenSESAME, systems structures are specified using reliability block diagrams or fault trees. So called failure dependency diagrams (FDD) are used to describe failures with a common cause, failure propagation and so on. Furthermore, shared repair resources and non-zero fail-over times between redimdant components can be modeled with Open-SESAME. 

Determine the event sequences leading to the hazardous events. Five cut sets are indicated on the Dependence diagram with "Failure" to get on the system as the most significant being a single event... 

Size-Dependent Diagram and Solubilities in Multicomponent Nanomaterials... 

For a binary gas mixture, the dependence diagram is a straight line cutting off ipii and ( 21 sections at the limits of the mixture flame propagation in the Cartesian coordinate system (fn - ni-... 

Consider the probability of a double engine failure on the Tristar aircraft (which has three engines). The dependence diagram (see Chapter 6) for this double failure condition could be any of the following ... 

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