birt ean 128

birt ean 128

birt ean 128

birt gs1 128

birt ean 128

birt ean 128,

birt gs1 128,
birt gs1 128,

birt gs1 128,
birt ean 128,
birt ean 128,
birt ean 128,
birt ean 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt gs1 128,
birt ean 128,

birt gs1 128,
birt ean 128,
birt gs1 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt ean 128,
birt gs1 128,

birt gs1 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt ean 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt ean 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt gs1 128,
birt ean 128,
birt ean 128,
birt ean 128,
birt gs1 128,
birt ean 128,
birt gs1 128,
birt ean 128,
birt gs1 128,

that a message will be delivered, and that it will be delivered to each intended recipient exactly once 1153 Scalability In addition to decoupling the interaction of subsystems, MOM also decouples the performance characteristics of the subsystems from each other Subsystems can be scaled independently, with little or no disruption to other subsystems MOM also allows the system to cope with unpredictable spikes in activity in one subsystem without affecting other areas of the system MOM messaging models contain a number of natural traits that allow for simple and effective load balancing, by allowing a subsystem to choose to accept a message when it is ready to do so rather than being forced to accept it This load balancing technique will be covered in more detail later in the chapter.

State-of-theart enterprise-level MOM platforms have been used as the backbone to create massively scalable systems with support for handling 162 million concurrent queries per hour and over 270,000 new order requests per hour [3] 1154 Availability MOM introduces high availability capabilities into systems allowing for continuous operation and smoother handling of system outages MOM does not require simultaneous or same-time availability of all subsystems Failure in one of the subsystems will not cause failures to ripple throughout the entire system MOM can also improve the response time of the system because of the loose coupling between MOM participants This can reduce the process completion time and improve overall system responsiveness and availability 116 When to use MOM or RPC Depending on the scenario they are deployed in, both MOM and RPC have their advantages and disadvantages.

H fx ; fy is known as the coherent transfer function. It is observed that a coherent imaging system is equivalent to an ideal low-pass lter, which passes all frequencies within the pupil function s 1 zone and cuts off all frequencies outside this zone. 10.8.2 Incoherent Imaging System

RPC provides a more straightforward approach to messaging using the familiar and straightforward synchronous interaction model However, the RPC mechanism suffers from in exibility and tight coupling (potential geometric growth of interfaces) between the communicating systems; it is also problematic to scale parts of the system and deal with service outages RPC assumes that all parts of the system will be simultaneously available; if one part of the system was to fail or even become temporarily unavailable (network outage, system upgrade), the entire system could stall as a result There is a large overhead associated with an RPC interaction; RPC calls require more bandwidth than a similar MOM interaction Bandwidth is an expensive performance overhead and is the main obstacle to scalability of the RPC mechanism [4].

Mode-specific construction, on the other hand, suggests that survey modes may be inherently different in their capabilities for obtaining accurate answers, especially when visual vs aural modes are used As a result, certain changes in question structure may sometimes achieve more equivalent answers than if unified mode construction procedures are followed Several examples of the need for mode-specific construction appear in the paragraphs that follow, including use of technological features available on the web and how people respond to open-ended questions across multiple modes One of the barriers to collecting equivalent data across survey modes is that initial benchmark surveys are often conducted without considering the possibility that the survey mode may need to be changed for the follow-up.

The RPC model is designed on the notion of a single client talking to a single server; traditional RPC has no built-in support for one-to-many communications The advantage of an RPC system is the simplicity of the mechanism and straightforward implementation An advantage that RPC has over MOM is the guarantee of sequential processing With the synchronous RPC model, you can control the order in which processing occurs in the system For example, in an RPC system you can be sure that at any one time all the new orders received by the system have been added to the database and that they have.

If 4p2 fx2 fy2 k2 , m is real, and each angular spectrum component is just modi ed by a phase factor e jmz. Plane wave components satisfying this condition are known as homogeneous waves. If 4p2 fx2 fy2 k2 , then m can be written as q m j 4p2 fx2 fy2 k2 and Eq. (4.3-8 ) becomes A fx ; fy ; z A fx ; fy ; 0 e mz 4:3-11 4:3-10

12/01