CS 566 Web Semantics ECommerce and Semantic Web

1
CS 566Web SemanticsE-Commerce and Semantic Web

• Professor
• Antoniou Grigoris
• June 2003

Antonis Misargopoulos misarg_at_csd.uoc.gr
Athina Tziaki tziaki_at_csd.uoc.gr
2
Introduction

• The growth of a wide range of e-commerce services
  is contributing to the increasing international
  trading of products and services
• The ability to find, interrogate and exchange
  knowledge is fundamental for Business-to-Business
  (B2B) and Business-to-Customer (B2C) e-commerce
• Semantic Web brings structure to the content of
  Web pages
• Semantic Web is extension of the current Web, in
  which information is given a well-defined meaning
• It will be able to support automated electronic
  services using semantics-based descriptions
• Ontologies and metadata are becoming increasingly
  prevalent and important in a wide range of
  e-commerce applications
• RDF is the technical foundation of the Semantic
  Web which provides a generic core data model

3
When Semantic Web Approaches E-Commerce

• Semantic Web will enable automated agents to
  describe and carry out more intelligent tasks on
  behalf of the user
• Tim Berners-Lee, the inventor of the WWW, has
  conceived a five-layer architecture for Semantic
  Web
• The syntax layer XML allows to markup arbitrary
  content by means of nested, attributed elements
• The data layer RDF allows the encoding,
  exchange and reuse of structured metadata.
  Contrary to XML, RDF allows assigning global
  identifiers to resources and allows referring and
  extending statements made in other documents
• The ontology layer describe structurally
  heterogeneous and distributed information sources
  of interest
• The logic layer consists of rules that enable
  inferences
• The proof layer allows the explanation of given
  answers generated by automated agents. This will
  require the translation of agents internal
  reasoning mechanisms into some unifying proof
  representation language.

4
Ontologies

• While e-service approaches to e-commerce is to
  become widespread, standarisation of ontologies,
  message content and message protocols will be
  necessary
• Because of the great XML-like modelling languages
  release, the challenge is to create small
  standards for communities to describe information
  with meaning
• Ontologies can be seen as metadata that
  explicitly represent semantics of data in
  machine-processable way
• Ontology-based reasoning services help people and
  computers to access the information they need,
  and effectively communicate with each other

5
Semantic E-Commerce Lifecycle (1/10)

• Lifecycle Stages
• Matchmaking A trader locates other traders that
  it could potentially do business with.
• This is done by some traders placing
  advertisements, and others making queries over
  these advertisements
• Negotiation The trader enters into negotiation
  with one or more of these potential business
  partners, to see if they can agree mutually
  acceptable terms of business.
• This is done through an interchange of
  negotiation proposals describing constraints on
  an acceptable deal. The outcome of this is an
  agreement.
• Contract Formation The agreement is transformed
  into a legally binding contract
• Contract Fulfilment The parties carry out the
  agreed transaction, within the parameters
  specified in the contract

6
Semantic E-Commerce Lifecycle (2/10)

• Matchmaking
• Matchmaking is the process whereby potential
  trading partners become aware of each others
  existence
• Provides an associated partially specified
  service description that defines the set of
  possible services the provider can offer which
  are of the interest to the buyers
• Despite different architectures and communication
  protocols
• we can identify clear roles which are common to
  all of them.
• we have a repository of information about
  services or service requirements, which is
  maintained by the repository host.
• agents adopting advertiser role are willing to
  advertise descriptions of services in the
  repository. They may be buyers, advertising a
  service request, or may be marketplaces offering
  environments where such services can be traded.
• agents adopting the seeker role similarly wish to
  locate appropriate advertisers. Seekers can query
  a repository, via the repository host, and may be
  able to browse the repository.

7
Semantic E-Commerce Lifecycle (3/10)

• Negotiation
• Negotiation stage of the e-commerce interaction
  lifecycle refines the abstract service
  specification from the matchmaking phase to a
  concrete agreement between two parties
• Negotiation can be one-to-one, one-to-many or
  many-to-many
• Negotiation protocols determine the interchange
  of messages which take place during the
  negotiation, and the roles by which the
  negotiation must abide
• In each case there are at least two negotiation
  participants trying to make a deal with each
  other
• There is at least one (possible more) negotiation
  host, responsible for enforcing the rules of the
  negotiation and ensuring it goes normally

8
Semantic E-Commerce Lifecycle (4/10)

• Negotiation
• Before negotiation can begin, the parties have
  already agreed roughly what the negotiation is
  about. So, this places a restriction on the
  parameters and values to be negotiated, which is
  called negotiation template
• The negotiation template refers to a common
  ontology accepted by all participants in the
  negotiation.
• It defines a schema for valid negotiation
  proposals that participants submit to each other
• The result of the negotiation process is an
  agreement

9
Semantic E-Commerce Lifecycle (5/10)

• Standardization take place at 3 levels
• Standards for business-specific ontologies which
  describe goods, services and contracts being
  traded
• Standards for specifying the format of
  advertisements, proposals, contracts and other
  constructs which are used during B2B interactions
• Standards that specify the protocols which
  traders use to interact with each other during
  different phases of the B2B lifecycle

10
Semantic E-Commerce Lifecycle (6/10)

• Description Language for B2B E-Commerce Lifecycle
  
• Requirements
• Description should offer a high degree of
  flexibility and expressiveness
• Descriptions need to share a common semantics
• Descriptions should easily lend themselves to
  performing the operations described in the
  negotiation and matchmaking sections
• Descriptions should express restrictions and
  constraints

11
Semantic E-Commerce Lifecycle (7/10)

• Description Language for B2B E-Commerce Lifecycle
  
• Why DAMLOIL is a good candidate?
• DAMLOIL offers support for types, which greatly
  enhances the expressiveness and modularity of the
  descriptions
• DAMLOIL offers support for ontologies. It is
  almost integrated with tools such as OilEd and
  Protégé which make the generation of new
  ontologies for service descriptions much easier
• All the operations can be expressed in terms of
  the subsumption operation. DAMLOIL descriptions
  lend themselves very well
• DAMLOIL offers some support for expressing
  constraints

12
Semantic E-Commerce Lifecycle (8/10)

• Description Language for B2B E-Commerce Lifecycle
  
• Using DAMLOIL

• The Description Ontology
• Description class is a common superclass for
  Advertisement, Query, Template and Proposal

• The PC Ontology
• PC class is a subclass of Product and must have
  at most one Processor and one amount of memory

13
Semantic E-Commerce Lifecycle (9/10)

• Description Language for B2B E-Commerce Lifecycle
  
• Using DAMLOIL

• The Service Ontology
• Two services are defined in this ontology Sales
  and Delivery

• The Participant Ontology
• Public information about prospective advertisers
  and negotiators.
• Built from information that individuals or
  companies are requested to provide at
  registration time.
• Such information is then used at matchmaking and
  negotiation time to verify compatibility of
  advertisements and proposals.

14
Semantic E-Commerce Lifecycle (10/10)

• Description Language for B2B E-Commerce Lifecycle
  
• Agreement Instance Example

15
E-commerce issues (1/2)

• Many consumers do not trust the Internet to
  provide robust security for online transactions,
  and many businesses neither trust e-commerce
  systems nor believe they will be able to evaluate
  or control their business risk when using them
• Lack of automation human intervention is
  required for browsing, selecting, ordering and
  paying for products
• Current e-commerce sites do not include semantic
  representations of data, services, processes, or
  business models that are readable by software
  programs (agents)

16
E-commerce issues (2/2)

• Three technologies will bring e-commerce to the
• next generation by increasing efficiency,
• compatibility, autonomy, and security
• Mobile Agents Automate Electronic Transactions
• Security and Trust Build a Web of Trust
• XML Create a Semantic Web

17
Mobile Agents Automate Electronic Transactions

• Mobile software agents are programs that act on
  behalf of a user or another program and, for a
  specified mission, are able to migrate from host
  to host on a network
• Numerous applications could benefit from mobile
  agent technology, such as Internet information
  retrieval and network management
• However, the greatest potential for mobile agents
  has been e-commerce applications in which the
  agents automate and facilitate the phases of
• Brokering of a transaction
• Negotiation of a transaction
• Payment of a transaction
• Delivery of a transaction

18
Security and Trust Build a Web of Trust

• Most of the security issues, such as
  confidentiality, authentication, integrity, and
  non - repudiation, are addressed by well-known
  cryptographic algorithms and protocols
• However, even if we have a secure channel
  connecting us to a party whose identity can be
  verified, we still have no way to confirm the
  trustworthiness of that party
• To meet this challenge, we need a trust
  management mechanism to manage the histories and
  reputation of parties involved in the business to
  create a web of trust
• While the mobile agent automates the electronic
  transactions, it also introduces new security
  threats

19
XML Create a Semantic Web

• Todays Web is a vast unstructured mass of
  information
• HTML was designed to provide a usable interface
  for humans, rather than to communicate with other
  machines. While HTML reflects the structure and
  limited presentation of a Web page, it conveys
  nothing about the meaning of the marked document
• Search engines and software programs have
  difficulty using information that is not
  semantically encoded
• Today, several industry-focused initiatives have
  been formed to work on standards based on XML for
  interoperable frameworks for e-commerce
  application domains
• Rules range from how to offer items for sale, to
  making payment choices, delivering products,
  generating receipts, and resolving problems

20
Integration Problems of XML-BasedCatalogs for
B2B Electronic Commerce

• Electronic marketplaces for Business-to-Business
  (B2B) electronic commerce bring together many
  online suppliers and buyers
• Each individual participant can potentially use
  his own format to represent the products in his
  product catalog
• A B2B mediator has to integrate both suppliers
  and buyers formats to allow them to do
  contracting with one another
• Given the dominance of XML, e-commerce
  integration technology must be based on the XML
  low-level integration architecture provided by
  the W3C consortium with XSLT and XPath languages

21
Product Description Standards (1/2)

• xCBL 3.0 developed by Commerce One2, Inc
• Provides a comprehensive set of standardized XML
  document formats, allowing buyers, suppliers and
  service providers to integrate their existing
  systems quickly and efficiently in the electronic
  marketplaces
• Internet Open Trading Protocol (IOTP) was
  developed within the Internet Engineering Task
  Force (IETF3) consortium
• Provides the data structures and communication
  protocols for payment transactions purchase,
  refund, authentication, deposit, and other
  protocols that occur in electronic commerce

22
Product Description Standards (2/2)

• Open Applications Group Integration Specification
  (OAGIS)
• Provides data structures, messaging formats and
  protocols for business integration. OAGIS defines
  a vocabulary of business terms and more than 90
  different types of business documents can be
  exchanged
• Real Estate Data Interchange Standard (RETS)
• Defines a protocol for implementing transactions,
  and incorporates an XML specification for
  general-purpose interchange. It also provides a
  compressed data interchange format and
  specification to allow the interchange of
  machine-interpretable property information

23
Catalog Integration (1/3)

• If a marketplace mediates between n suppliers and
  m buyers, then it must be able to map each of the
  n suppliers catalogs into m buyers formats
  performing nxm mappings
• The numbers n and m may be high enough to make
  the problem of creating and maintaining these
  catalog integration rules nontrivial

24
Catalog Integration (2/3)

• Unified Catalog (the UC), only requires the
  marketplace to perform mapping between each
  supplier or buyer catalog and the UC, and
  therefore requires only nm mappings

• There are two opposing strategies for selecting
  the elements for
• inclusion in the UC
• The unified catalog stores the minimum
• core number of attributes for each product
• The unified catalog stores the maximum
• possible number of attributes

25
Catalog Integration (3/3)

• In both strategies the UC can change if we add a
  new
• catalogue
• In strategy (a)
• The addition of a more detailed catalog will not
  change the UC
• The addition of a less detailed catalog will
  reduce the granularity level of the UC. As a
  result, this strategy bounds the granularity
  level of the UC to the less detailed catalog,
  which is unacceptable for most B2B systems
• In strategy (b)
• The addition of a new catalog that is less
  detailed than the UC will not influence the
  latter
• The addition of a more detailed catalog will
  require updates to the UC so that it will not be
  less detailed than the former

26
Integration at the XML Catalog Level (1/5)

• Four types of mapping between the attributes of
  C1 and
• C2 are possible
• one-to-one mapping (11)
• It occurs when the element of C1 has a semantic
  equivalent in C2, i.e. element StateOrRegion in
  IOTP standard is equivalent to Province in the
  UC. If the element is encoded by an XML attribute
  in C1 and by an XML element in C2 then the rule
  can be expressed as follows (from IOTP to UC)

ltxslfor-each select"PostalAddress"gt ltProvincegt
ltxslvalue-of select"_at_StateOrRegion"/gt lt/Provinc
egt lt/xslfor-eachgt
27
Integration at the XML Catalog Level (2/5)

• one-to-many mapping (1n)
• It occurs when an element in C1 has to be
  translated into several elements in C2. For
  example, ADDRLINE in OAGIS semantically
  corresponds to the pair of attributes Street and
  House in the UC
• XSLT rules must be extended with small XPath
  expressions (element parsers) that will split the
  elements as required

ltADDRLINEgtDe Boelelaan, 1081alt/ADDRLINEgt

• ltADDRESSgt
• ltADDRLINEgt
• ltSTREETgtDe Boelelaanlt/STREETgt
• ltHOUSEgt1081alt/HOUSEgt
• lt/ADDRLINEgt
• lt/ADDRESSgt

• ltSTREETgt
• ltxslvariable name"addrline" select"ADDRLINE"/gt
• ltxslvalue-of select"substring-before(addrline,'
  ,')"/gt
• lt/ STREET gt
• ltHOUSEgt
• ltxslvariable name"addrline" select"ADDRLINE"/gt
• ltxslvalue-of select"substring-after(addrline,',
  ')"/gt
• lt/ HOUSE gt

28
Integration at the XML Catalog Level (3/5)

• many-to-one mapping (n1)
• It occurs when two or more elements from C1 have
  to be translated into one element in C2. For
  example, the Street and House elements in the UC
  must be translated into the element ADDRLINE in
  OAGIS. This can be done by means of XSLT in the
  following way

ltxslfor-each select"address"gt ltADDRLINEgt ltxslva
lue-of select"Street"/gt, ltxslvalue-of
select"House"/gt lt/ADDRLINEgt lt/xslfor-eachgt
ltADDRLINEgtDe Boelelaan, 1081alt/ADDRLINEgt
29
Integration at the XML Catalog Level (4/5)

• Many to-many mapping (nn)
• It occurs when a piece of a description is spread
  over several elements without evident
  partitioning of information between them. For
  example, Street, House, and PObox elements of the
  UC correspond to the pair (AddressLine1,
  AddressLine2) in IOTP without any indication
  where street, house, and postbox information
  should be stored within these two address lines.
  Mapping of a structured UC record into a less
  structured IOTP record can be done
  straightforwardly

ltxslfor-each select"address"gt ltAddressLine1gtltxsl
value-of select"Street"/gt ltxslvalue-of
select"House"/gtlt/AddressLine1gt ltAddressLine2gtP.O.
Box ltxslvalue-of select"PObox"/gt
lt/AddressLine2gt lt/xslfor-eachgt
30
Integration at the XML Catalog Level (5/5)

• If an element was mapped into the UC with one 1n
  mapping then the reverse mapping will require one
  n1 mapping
• Most of the rules (89) represent one-to-one
  mappings, while the other types only appear in
  special cases, once or twice for each catalog
  standard

31
Existing Frameworks and Applications

• MOMIS
• SEMANTICEDGE
• KAON
• ONTOWEB
• ONTOKNOWLEDGE

32
E-Commerce Data Classification MOMIS

• To interact with a specific local source, MOMIS
  uses a Wrapper, which has to be placed over each
  source.
• The wrapper translates metadata descriptions of a
  source into the common ODL representation.
• The core of the MOMIS system is the Mediator.
• The Global Virtual Schema module processes and
  integrates descriptions received from wrappers to
  derive the global shared schema by interacting
  with different service modules, namely ODB-Tools,
  an integrate environment for reasoning on object
  oriented database based on Description Logics,
  WordNet lexical database that supports the
  mediator in building lexicon-derived
  relationships, and ARTEMIS tool that performs the
  clustering operation

33
MOMIS Architecture
MOMIS (Mediator envirOnment for Multiple
Information Systems) is a mediator-based system
aiming to extract and integrate information from
heterogeneous data sources, such as relational,
object, semi-structured sources (XML)
34
SemanticEdge (1/2)

• SemanticEdge has developed a state of the art
  multilingual natural language (text and voice)
  dialog system capable of handling dialogs with
  humans wanting to access information, for
  example, to purchase products and services
• The technology extends naturally to Customer
  Relations Management (CRM) and other e-business
  functions
• This technology depends on several distinct
  technology areas within Artificial Intelligence
  natural language processing, including deep
  language processing and statistical analyses
  machine learning, including inductive learning
  speech recognition automated dialog generation,
  both user and content specific and knowledge
  representation and ontologies

35
SemanticEdge (2/2)

• The system mediates between humans and
  information.
• That is, it mediates between an information space
  and a humans conceptualization of that
  information space for example, between a product
  space and a customers conceptualization of that
  product space, and how they will consequently go
  about searching and querying that product space
• Users hold negotiations with the system, which is
  mediating access to the product spaces, and it
  will ask questions of them.
• This requires the system to have the ability to
  guide those dialogs according to a representation
  of that product space.
• This ability to a large extent is supported by
  ontologies
• Financial Application demo

36
References

• 1 Semantic Web Support for Business-to-Busines
  s E-Commerce Lifecycle David Trastour, Claudio
  Bartolini and Chris Preist. Trusted E-Services
  Laboratory, HP Laboratories Bristol. April 5th
  2002
• 2 Towards a Semantics for the Web Christopher
  Welty. Vassar College Computer Science Dept.
  Poughkeepsie, NY 12604-0462, USA
• 3 A Semantic Web Approach to Service
  Description for Matchmaking of Services David
  Trastour, Claudio Bartolini and Javier
  Gonzalez-Castillo. HP Labs, Filton Road, Bristol
  BS34 8QZ, UK
• 4 Reduction of price dispersion through
  Semantic E-Commerce A Position Paper Tanya Gupta
  and Abir Qasem
• 5 An Analysis of Integration Problems of
  XML-Based Catalogs for B2B Electronic Commerce.
  B. Omelayenko, D. Fensel. In Proceedings of the
  9th IFIT 2.6 Working Conference on Database
  Semantics (DS-9), April 25-28, Hong-Kong, 2001.
• 6 A Data Integration Framework for E-commerce
  Product Classification. S. Bergamaschi, F.
  Guerra and M. Vincini.
• CSITE-CNR viale Risorgimento 2, 40136 Bologna,
  Italy.
• 7 A Layered Integration Approach for Product
  Descriptions in B2B E-commerce. Borys Omelayenko
  and Dieter Fensel.
• 8 Next-Generation E-Commerce XMLMobile
  AgentTrust. CG topics 4/2000. Dr. Jian Zhao,
  Thomas Blum.
• 9 Enterprise-standard ontology environments for
  intelligent e-business. Alan Flett, Mike Brown
• 10 Syntactic-Level Ontology Integration Rules
  for E-commerce. Borys Omelayenko. In
  Proceedings of the 14th International FLAIRS
  Conference (FLAIRS-2001), Key West, FL, May
  21-23, 2001.
• 11 A Two-Layered Integration Approach for
  Product Information in B2B E-commerce. Borys
  Omelayenko and Dieter Fensel. In Proceedings of
  the Second International Conference on Electronic
  Commerce and Web Technology (EC WEB-2001),
  Munich, Germany, September 4-6, 2001.
• 12 http//www.semanticedge.com/

37
Related Papers

• 1 The Contract Net protocol High-level
  communication and control in a distributed
  problem solver R.G. Smith. In Proceedings
  Computing Systems, pages 186-192, Washington, DC,
  1979. IEEE Computer Society.
• 2 UDDI. Universal Description Discovery
  Integration Technical White Paper, 2000
• 3 Auction theory a guide to the literature P.
  Klemperer. Journal of Economic Surveys, 13(3)
  227-286, 1999
• 4 OilEd a reason-able ontology editor for the
  semantic web S. Bechhofer, I.Horrocks, C.Goble,
  and R.Stevens. In Working Notes of the 2001 Int.
  Description Logics Workshop (DL-2001), pages 1-9,
  2001.
• 5 Knowledge Modeling at the Millenium The
  Design and Evolution of Protégé W. Grosso, H.
  Eriksson, R. Fergerson, J. Gennari, S. Tu, and M.
  Musen. In Proceedings of the 12th International
  Workshop on Knowledge Acquisition, Modeling and
  Management (KAW 99), 1999.
• 6 Proceedings of the International Workshop on
  Description Logics (DL'99) I.Horrocks. FaCT and
  iFaCT. In P. Lambrix, A. Borgida, M. Lenzerini,
  R. Möller, and P. Patel-Schneider.
• 7 Description logics for matchmaking of
  services J. González-Castillo, D. Trastour, and
  C. Bartolini. In Proceedings of the KI-2001
  Workshop on Applications of Description Logics,
  2001.