OTRAS ACTIVIDADES DE LA SUBDIRECCIÓN

ORB – manages all communication b/t components and enables them to interact in a heterogeneous

and distributed environment.

 ORB works independently of the platforms where the objects reside, which provides greater interoperability.

 ORB relies on object services to provide access control. Track relocated objects, and create objects

 ORB is the middleware that est. the client/server relationship b/t objects.

 When a client needs to access an object on a server the ORB intercepts the request and is responsible for finding the object.

 Once the object is found, ORB invokes an operation, passes the parameters, and returns the results to the client.

 When objects communicate to each other they use pipes, communciaition services. ORB is a pipe.

 ORBs are mechanisms that enable objects to communicate locally or remotely

COBRA – Common Object Request Broker Architecture – provides interoperability among th vast

array of SW, platforms, and HW in environments.

 Enables applications to communicate with one another no matter where the application is located or who developed it.

CASE Computer Aided SW Engineering – a general term for tools that help make program applications

more quickly and with fewer errors in an automated fashion.

 First CASE tools were translators, compilers, assemblers, linkers, and loaders

 Graduated to program editors, debuggers, code analyzers, and version control mechanisms.

 CASE applies engineering principals to the development and analysis of specifications using specific tools.

 Integrated-Computer Aided SW Engineering (I-CASE) – When automation covers the

complete life cycle of a product.

 CASE tools – used for one specific part of the life cycle

 Rapid Prototyping – more CASE tools utilize these technologies that enable applications to

be developed faster with higher quality and lower cost.

 A prototype can be made so that testing can begin earlier in the development process

Prototyping Building a model of the gathered requirements of a SW product can show the customer where the development team is headed and its interpretation of the customers stated requirements.

 Prototype also enables testing to being earlier in the development process so that errors or problems can be uncovered and addressed.

 Security testing can also be done in earlier stages

COM and DCOM COM – Component Object Model – defines how components interact and provides an architecture

for simple interprocess communication (IPC)

 Enables apps to use components on the same systems.

DCOM – Distributed Component Object Model – Supports the same model for component

interaction, but supports distributed IPC

 DCOM enables applications to access objects that reside in different parts of the network

 Has a library that takes care of session handling, synchronization, buffering, fault identification and handling, and data format translation

 Acts as a middleware

 DCOM provides ORB services, data connectivity services, distributed messaging services, and distributed transaction services layered over its RPC mechanism

 DCOM uses the same interface as COM

 Other types of middleware:

 ORB

 MOM – Message Oriented Middleware

 RPC

 ODBC

ODBC A de facto standard that provides a standard SQL dialect that can be used to access many types of rational DB. ODBC is the middleman b/t apps and DBs.

OLE Object Linking and Embedding – provides a way for objects to be shared on a local personal

computer and to use COM as their foundation.

 Linking – capability for one program to call another program.

 Embedding – capability to place a piece of data inside a foreign program or document DDE Dynamic Data Exchange – enables apps to share data by providing IPC. Based on the client/server

model and enables 2 programs or apps to send commands to each other directly

DCE Distributed Computing Environment – Standard that was developed by the Open SW Foundation

(OSF). It is basically middleware that is available to many venors to sue.

 DCE provides an RPC servers, security service, directory service, time service, and distributed file support

 DCE and DCOM provide the same functionality, but DCOM is Microsoft proprietary.

 DCOM uses a Globally Unique Identifier (GUID) and DCE uses a Universal Unique

Identifier (UUID) and are both used to uniquely identify users, resources, and components

w/in an environment.

 RPC function collects the arguments and commands from the sending program and prepares them for tansmission over the network.

 RPC determines the network transport protocol that is to be used and finds the receiving host’s address in the directory service

Enterprise Java Bean EJB – A java component is called a java bean. A structural design for the development and

to allow different applications to be able to communicate across a network environment.

Expert Systems and Knowledge based systems

Expert Systems are also called knowledge-based systems – use artificial intelligence to solve

problems.

 Expert system is a computer program containing a knowledge base and a set of algorithms and rules used to infer new facts from knowledge and incoming data.

 AI SW uses nonnumerical algorithms to solve complex problems, recognize hidden patterns, prove theorems, play games, mine data, and help in forecasting and diagnosing a range of issues.

 Expert systems emulate human logic to solve problems that would usually require human intelligence and intuition.

 Expert system will attempt to think like a person, reason through different scenarios, and provide an answer even w/out the necessary data.

 Rule-based programming – a common way of developing expert systems. Rules are based

on if-then logic units that specifies a set of actions to be performed for a given situation

 This is one way that expert systems are used to find patterns, which is called

pattern matching.

 A mechanism called the inference engine, automatically matches facts against patterns and determines which rules are applicable.

An expert system consists of 2 parts: