Filtering & Selecting Semantic Web Services with Interactive Composition Techniques By Evren Sirin, Bijan Parsia, and James Hendler Presenting By : Mirza Tania Nasreen Mohammad Hasan

2 Outline of the Presentation Main Idea of the Paper Works done by Authors Relevant Terms Comparisonal Work Flow Technology Used Implementation details Conclusion

3 Main Idea of the Paper Composition of Web Services

4 Why Composition ???  Goal: applications will be able to communicate each other very flexibly to achieve some combined and new functionality from existing ones.  Present Condition: failed to achieve this goal  the expected ability to compose web services has not been achieved yet

5 Works Done by the Authors Developed  goal-oriented  interactive composition approach Implemented  In a Prototype system Help the users to dynamically compose web services from internet with filtering capabilities

6 Web Service  Web Service is a software system designed to support interoperable Machine to Machine interaction over a network. [ W3C ]  A web service is a collection of protocols and standards used for exchanging data between applications or systems. [ Wikipedia ] No Semantics in WSDL Current State of SOA

7 Drawback with Example

8 Semantic Web Service World Wide Web Semantic Web  a services whose properties, capabilities, interfaces, and effects are encoded in an unambiguous, machine- understandable form. Web Service Semantic Web Service Web Service + Semantics = Semantic Web Service [ HOW & WEHERE ] [ WHAT & WHY ]

9 Why Semantics ????  (Discovery) Neither WSDL nor UDDI allows for software to determine what a Web service offers to the client. A Semantic Web service describes its properties and capabilities so that software can automatically determine its purpose.  (Invocation) A Semantic Web service provides a descriptive list of what an agent needs to be able to do to execute and fulfill the service. This includes what the inputs and outputs of the service are.  (Monitoring) services can interoperate with each other seamlessly and can combine results for a valid solution. Dynamic Composition

10 Why Semantics? An Example Semantic Annotation is the main concept behind Dynamic Composition DictionaryTranslator wordtranslated wordwordmeaning French to English Dictionary French word translated English wordmeaning How & Where WSDL How & Where WSDL string WS 1 WS 2 + What & Why + What & Why

11 How Semantics ????  UDDI Dynamic Composition  WSDL  SOAP Standards for Service Directory Standards for Description Standards for Messaging Protocols First System to directly combine the OWL-S semantic service descriptions with actual invocations of the WSDL descriptions. WSDL + OWL-S = Semantic Web Service Description

12 Major Focuses of the Paper Filtering and Selecting Semantic Web Services with Interactive Composition Techniques Filtering Selecting Interactive Composition Techniques

13 Filtering When a service goes into the composition, this service’s information about input, output, preconditions, and effects (IOPE) serves to automatically filter the services whose outputs are incompatible with the current selection. Filter is designed to examine each input or output request for certain qualifying criteria and then process or forward it accordingly. Filtering helps to determine the service that best fits user’s/clients personal preferences. Filtering for their tool done by using matchmaking algorithms

14 Selecting

15 Interactive Composition A successful, executable composition correctly combines a set of compatible components to achieve the composition’s overall goal. At each step, their system adds a new service to the composition and filters further possibilities based on the current context and user decisions. Gradually generates the composition with a forward or backward chaining of services. Filtering + Selecting = Interacting Compositing Techniques

16 Step-by-step Composition Fixing a GOAL Select 1 st web Service Filtering Select 2 nd web Service Compose 2 web services RESULT Auto. Filtering List of Services Selecting Auto. Filtering List of Services Selecting Monitoring Selection Manual CompositionDynamic CompositionPartial Automation of Composition

17 Creating Semantic Service Description – OWL-S OWL : Enables greater access only to content OWL-S ( formerly DAML-S): Enables greater access to the Web Services OWL-S partitions a Web Service’s description into three components : 1. Service Profile - IOPE parameters - service parameter 2. Process Model -Atomic Process -Composite Process 3. Grounding -Mapping from OWL-S to WSDL

18 Translation from WSDL to OWL-S WSDL Operation ≡ OWL-S Atomic Process WSDL message parts ≡ OWL-S Process’s Parameters Difficulties with Type Conversion :  Message parts are described by XML Schema data types  OWL itself permits only a subset (constrained range) of XML Schema data types (integers / strings).  OWL references data types by URI  No canonical way in XML Schema to determine a URI for a complex data type Preferred Solution : Parameter types of OWL-S services be OWL classes

19 Translation from WSDL to OWL-S cont’d… Author’s Solution:  Treated the WSDL-supplied types as descriptions of the service parameters  i.e. the serialization of the values the process actually uses.  Extended the OWL-S grounding to include marshaling and unmarshaling functions using XSLT  Unmarshalling function : XML Schema type to an RDF graph serialized in the RDF/XML exchange syntax  That graph encodes the relevant assertions about the individual, which becomes the actual input to the service Difficulties:  It’s difficult to write XSLT that can handle all the legal serializations of a given RDF graph.

20 Implementation The Prototype System

21 Implementation 4 Types of IOPE Matching:  Exact: If advertisement A and request R are equivalent concepts  PlugIn: If request R is a subconcept of advertisement A  Subsume: If request R is a superconcept of advertisement A  Fail: No match.

22 Matching IOPE Only IO was used for matching Specifications of PE are still an open OWL-S issue Exact and Plug-In matches between the parameters of ServiceProfiles yields useful results Returns an ordered list

23 Matching Service Parameters To get rid of long list of available choice Service names themselves might not contain enough information Means of introducing more user constraint Applies the result of this new query to the previous result set

24 Matching Service Parameters

25 Generating and Executing Composed Services Generation :  Each Composition ≡ OWL-S CompositeProcess  It can also be advertised, discovered, and composed with other services  Generates exactly such a CompositeProcess description  Creates the corresponding ServiceProfile Execution :  Invoking each individual services and passing the data  Client program serves as the central control authority

26 Improvement and further automation Strong need for a suitable set of service descriptions of sufficient and compatible detail to support Converting the IO type descriptions from XML Schema data types to OWL classes Removing human interaction from the loop by integrating a planner Introduce machine learning – better and preferred suggestions

27 Conclusion Semantic Web Semantic Web Service Maturity Hill Web Service Full Automation Partial Automation of Composition

28 References Filtering and Selecting Semantic Web Services with Interactive Composition Techniques. IEEE Intelligent Sytems. 19(4): (2004). Semantic Web Services. IEEE Intelligent Systems, Volume: 16 Issue: 2, March-April 2001, Pages: Semantic Web Service Architecture — EvolvingWeb Service Standards toward the Semantic Web. American Association for Artificial Intelligence ( Bringing Together Semantic Web and Web Services. Proceedings 1st International Semantic Web Conference (ISWC 02),

29 Thank You...