Performance trees

Company executives strive to increase company value. Companies with higher ROIC and revenue growth are valued more highly in the stock market and over the long term lead to higher total return to 

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The decision tree can be considered as a road map which indicates the chronological order in which a series of actions will be performed, and shows several possible courses, only one of which will actually be followed. 

Finally, the evaluation can be performed by rolling back the tree, starting at the leaves, and working backwards towards the trunk of the tree. 

Sensors on the tree allow the control module to transmit data such as tubing head pressure, tubing head temperature, annulus pressure and production choke setting. Data from the downhole gauge is also received by the control module. With current subsea systems more and more data is being recorded and transmitted to the host facility. This allows operations staff to continuously monitor the performance of the subsea system. 

Parallelizing this method was not difficult, given that we already had parallel versions of several multipole algorithms to start from. The entire macroscopic assembly, given its precomputed transfer function, is handled by a single processor which has to perform k extra multipole expansions, one for each level of the macroscopic tree. Each processor is already typically performing many hundreds or thousands of such expansions, so the extra work is minimal. 

Our multipole code D-PMTA, the Distributed Parallel Multipole Tree Algorithm, is a message passing code which runs both on workstation clusters and on tightly coupled machines such as the Cray T3D/T3E [11]. Figure 3 shows the parallel performance of D-PMTA on a moderately large simulation on the Cray T3E the scalability is not affected by adding the macroscopic option. 

W. T. Rankin and J. A. Board, Jr., A Portable Distributed Implementation of the Parallel Multipole Tree Algorithm, Proceedings, Fourth IEEE International Symposium on High Performance Distributed Computing, IEEE Computer Society Press (1995), pp. 17-22. 

Rankin, W., Board, J. A portable distributed implementation of the parallel multipole tree algorithm. IEEE Symposium on High Performance Distributed Computing. Duke University Technical Report 95-002. 

Methods for performing hazard analysis and risk assessment include safety review, checkhsts, Dow Fire and Explosion Index, what-if analysis, hazard and operabihty analysis (HAZOP), failure modes and effects analysis (FMEA), fault tree analysis, and event tree analysis. Other methods are also available, but those given are used most often. 

Oakmoss. Extracts of oakmoss are extensively used in perfumery to furnisli parts of the notes of the fougnre or chypre type. The first step in the preparation of an oakmoss extract is treatment of the Hchen Evemiaprunastri (L.) Ach., collected from oak trees mainly in southern and central Europe, with a hydrocarbon solvent to obtain a concrete. The concrete is then further processed by solvent extraction or distillation to more usable products, of which absolutes are the most versatile for perfumery use. A definitive analysis of oakmoss volatiles was performed in 1975 (52). The principal constituents of a Yugoslav oakmoss are shown in Table 15 (53). A number of phenoHc compounds are responsible for the total odor impression. Of these, methyl P-orcinol carboxylate is the most characteristic of oakmoss. 

Pimento Berry Oil. The pimento or allspice tree, Pimenta dioca L. (syn. P. officinalis, Liadl.), a native of the West Indies and Central America, yields two essential oils of commercial importance pimento berry oil and pimenta leaf oil. The leaf oil finds some use ia perfumery for its resemblance to clove leaf and cinnamon leaf oils as a result of its high content of eugenol. Pimento berry oil is an item of commerce with extensive appHcation by the flavor industry ia food products such as meat sauces, sausages, and pickles, and moderate use ia perfumery, where it is used primarily as a modifier ia the modem spicy types of men s fragrances. The oil is steam-distilled from dried, cmshed, fully grown but unripe fmits. It is a pale yellow Hquid with a warm-spicy, sweet odor with a fresh, clean topnote, a tenacious, sweet-balsamic-spicy body, and a tea-like undertone. A comparative analysis of the headspace volatiles of ripe pimento berries and a commercial oil has been performed and differences are shown ia Table 52 (95). 

Coupling of analytical techniques (detectors) to high-performance liquid chromatographic (HPLC) systems has increased in the last tree decades. Initially, gas chromatography was coupled to mass spectrometry (MS), then to infrai ed (IR) spectroscopy. Following the main interest was to hyphenate analytical techniques to HPLC. 

A logic model that graphically portrays the combinations of failures that can lead to a particular main failure (TOP event) or accident of interest. Given appropriate data, fault tree models can be quantitatively solved for an array of system performance characteristics (mean time between failures, probability of failure on demand, etc.)... 

A significant development of the study was the use of event trees to link the system fault trees to (lie accident initiators and the core damage states as described in Chapter 3. This was a response to the ditficulties encountered in performing the in-plant analysis by fault trees alone. Nathan Villalva and Winston Little proposed the application of decision trees, which was recognized by Saul Levine a.s providing the structure needed to link accident sequences to equipment failure. 

Figure 3.4.4-1 summarizes conventional fault tree symbols. The many symbols are daunting, but remember that the computer only performs AND (Boolean multiplication) and OR (Boolean addition) operations. All else are combinations of these. 

A fault tree may either stand alone or be coupled to an event tree to quantif" bability. The top event in either case is the abjective of performing the analysis. If tht is the reliability of a system under specific conditions - then that is the top event. If it is to qua iify a node of an event tree the top event title is that of that particular node subject to the condi ons imposed by the preceding modes. 

Testing schemes generally affect complete subsystems hence, consideration of each hardware element is unnecessary. Tests of redundant portions of a system are particularly important, and may be constrained by the technical specifications which must be reflected in the fault tree. Testing may require the reconfiguration of systems for the test, which may prevent the performance of their designed function. In this case, other members of the redundancy must be available, but may fail. Failure to restore a system after test significantly increases the risk. 

Human factors, discussed in Section 4.2, enter a fault tree in the same manner as a component failure. The failure of manual actions, that prevent or mitigate an accident, are treated the same as hardware failures. The human error failure probability is conditioned by performance sluiping factors imposed by stress, training and the environment. 

Human errors may be dependent on the specific accident sequence displayed in the event tree, and, for that reason, may be included in the event tree. This requires the human-factors specialist to consider the context of the error in terms of stress, operator training in response to the accident, di.tgnosiic paiierns, environmental, and other performance-shaping factors. 

Function event trees include primarily the engineered safety features of the plant, but other systems provide necessary support functions. For example, electric power system failure amid reduce the effectiveness of the RCS heat-removal function after a transient or small UJ( A. Therefore, EP should be included among the systems that perform this safety function. Siipfiort systems such as component-cooling water and electric power do not perform safety functions directly. However, they significantly contribute to the unavailability of a system or group of systems that perform safety functions. It is necessary, therefore, to identify support systems for each frontline ssstcm and include them in the system analysis. 

A system event tree provides this display and uses the Tech Spec ciiicna (n specify the func tion. Figure 3.4.5-4 shows a system event tree developed from the function event tree presented as Figure 3.4.5-2, It should be noted that the functions RS, COl, C02 and ECR are accomplished by systems and are thus unchanged ongoing from a function to system event tree. ECI is quiic complex and may be performed by various system combinations such as 2 or 1 core spray (CS) loops, or various combinations of low pressure in jection (LPCI),... 

Functional and hardware relationships between systems are considered in selecting the order of event tree headings. Systems that depend on the operation of other systems in order to perform their function should be listed after the other systems. For example, the decay-heat removal system... 

Postprocessing cutset information such as cutset acronyms and cutset searches is performed by REPORT (BNL written to aid in preparation of NUREG/CR-4207). A standard output format for the fault tree codes would facilitate postprocessing,... 

PSAPACK 4,2 is an integrated fault/event tree package with capabilities for easily examining results and performing recalculations. There are two levels of processing in the package ... 

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