Background Information in .NET

Integrated QR Code 2d barcode in .NET Background Information

Whenever events are available on a handle, its associated thread reads the event and places it on a queue that is processed sequentially by the reactor implementation. This design can be inefficient, however, because it serializes all the event handler threads. Thus, synchronization and context switching overhead increases without enhancing applicationlevel parallelism. Non-pre-emptive. In a single-threaded application, concrete event handlers that borrow the thread of their reactor can run to completion and prevent the reactor from dispatching other event handlers. In general, therefore, an event handler should not perform long duration operations, such as blocking I/O on an individual handle, because this can block the entire process and impede the reactor's responsiveness to clients connected to other handles. To handle long-duration operations, such as transferring multimegabyte images [PHS96], it may be more effective to process event handlers in separate threads. This design can be achieved via an Active Object (369) or Half-Sync/Half-Async (423) pattern variant that performs services concurrently to the reactor's main event loop. Complexity of debugging and testing. It can be hard to debug applications structured using the Reactor pattern due to its inverted flow of control. In this pattern control oscillates between the framework infrastructure and the method call-backs on application-specific event handlers. The Reactor's inversion of control increases the difficulty of 'single-stepping' through the run-time behavior of a reactive framework within a debugger, because application developers may not understand or have access to the framework code. These challenges are similar to the problems encountered trying to debug a compiler's lexical analyzer and parser written with lex and yacc. In such applications, debugging is straightforward when the thread of control is within user-defined semantic action routines. After the thread of control returns to the generated Deterministic Finite Automata (DFA) skeleton, however, it is hard to follow the program's logic.

Let us assume that the cable is three-core, X = 0.08 m / m (see section 4.2.1.4): phase: neutral:

Value2 = Low of 1 bar ago;

specialized to several types of things such as products, documents, people, and machines. A formal definition for information and information system is as follows: Information is the knowledge increment brought about by a receiving action in a message transfer; i.e., it is the difference between the conceptions interpreted from a [3] received message and the knowledge before the receiving action. [FRISCO 96] Consequences The consequence of not using this pattern when modeling systems that involve both information and the concept the information represents is that they become intermingled and result in a model that is hard to maintain and use as the basis for the information system. By using the Thing-Information pattern, the resource and the information about it are clearly separated, meaning that future maintenance of the models and the building of information systems based on the models will be easier. Example B2B Agency is a company that performs market analysis for other companies. B2B collects information about companies, including who their customers, subcontractors, competitors, and potential clients (prospects) are. The market analysis B2B performs is based on this information. B2B Agency then sells and distributes the market analysis report to actors in the marketplace, who may also be companies that B2B Agency collects information about. The market analysis contains information gathered for the purpose of increasing sales for B2B s customers. These customers are also operating in the marketplace, meaning that information about them is also present in the market analysis report. The customers can study the collected information about other actors in their marketplace and compare this with the information that B2B Agency has collected about them sometimes referred to as benchmarking (see Figure 7.34).

Universal Mobile Telecommunications System (UMTS)

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Table 7.2 Variable/object v[i] v[i].Home v[i].Box v[i].degree e[i][j] Pt1,Pt2 nv nLinks RButtonFlag Class CPoint CRect int int int int int int

circuit lengths shown in Figure 4-21 cross-section of the circuit phase conductors reactance per unit length of the conductors cross-sectional area of the earth conductor resistivity of the conductors equal to 1.5 times that at 20 C (which minimizes the short-circuit current)