Asset Categorization

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Asset Categorization

• Asawin Rajakrom

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Course Syllabus

• This course describes how the power distribution
  network assets are modeled and categorized into
  classes and draw a relationships among those
  classes. The class attribute represents a network
  data that will be used for inducing asset
  conditions, costs, probability of network failure
  as well as social and environment factors that
  influence the asset investment decision. The
  modeling approach bases on the prominent a Common
  Information Model (CIM) modeling method that used
  for representing real-world objects and
  information entities exchanged within the value
  chain of the electric power industry.
• Underpinning the CIM knowledge representation are
  several methods and methodologies such as UML,
  XML, and RDF. The course provides all necessary
  background of these technologies. In addition,
  engineering disciplines such as knowledge
  engineering and ontological engineering which
  emphasizes the knowledge acquisition and ontology
  development are also explicated. Combining them
  all together, attendees will equip themselves
  with all necessary knowledge to model not just
  power distribution system assets but all the
  other area of knowledge modeling.

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Course Outline

• Categorization principle terminologies
• Unified modeling language
• eXtensible markup language
• Resource description framework
• Common information model
• knowledge engineering
• Ontological development
• Power distribution network asset categorization

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Asset Categorization

• Categorization Principle Terminologies

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Categorization Overview

• The basic cognitive process of arranging into
  classes or categories
• The process in which ideas and objects are
  recognized, differentiated and understood.
  Categorization implies that objects are grouped
  into categories, usually for some specific
  purpose. Ideally, a category illuminates a
  relationship between the subjects and objects of
  knowledge
• The function of category systems and asserts that
  the task of category systems is to provide
  maximum information with the least cognitive
  effort
• The structure of the information so provided and
  asserts that the perceived world comes as
  structured information rather than as arbitrary
  or unpredictable attributes

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Controlled Vocabulary

• Way of describing a concept under a single word
  or phrase
• May vary in its definition and usage when use in
  different domain
• An established list of standardized terms used
  for both indexing and retrieval of information
• The list of terms should be controlled by and be
  available from a controlled vocabulary
  registration authority in order to make a it
  unambiguous, non-redundant

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Controlled Vocabulary

• At a minimum, the following two rules should be
  enforced to make true in practice
• If the same term is commonly used to mean
  different concepts in different contexts, then
  its name is explicitly qualified to resolve this
  ambiguity.
• If multiple terms are used to mean the same
  thing, one of the terms is identified as the
  preferred term in the controlled vocabulary and
  the other terms are listed as synonyms or aliases.

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Classification

• Systematic arrangement in groups or categories
  according to established criteria
• Act or process of putting people or things into a
  group or class
• Establishing the correct class (or category) for
  an object where an object needs to be
  characterized in terms of class to which it
  belongs

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Classification

• Classification is an approach to systematically
  arranging objects into categories according to
  established criteria.
• Objects are the physical and conceptual things we
  find in the universe around us Hardware,
  software, documents, animals, human beings, and
  even concepts.
• Classification allows to us manage things easily
  by grouping them into certain category under
  specific criteria and then manipulate against
  established condition.

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Taxonomy

• An orderly classification of plants and animals
  according to their presumed natural relationships
• A hierarchy created according to data internal to
  the items in that hierarchy
• An orderly classification of objects into
  hierarchical structure using a parent-child
  relationships
• Using parent-child relationships in taxonomy
  e.g., whole part, genus species, type
  instance, or class subclass.
• Differ from classification in the sense that it
  classifies in a structure according to some
  relation between the entities and that a
  classification uses more arbitrary (or external)
  grounds

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Taxonomy
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Ontology

• A branch of metaphysics concerned with the nature
  and relations of being
• A system of concepts used as building blocks of
  an information processing system
• Consists of concepts, hierarchical (is-a)
  organization of them, relations among them, in
  addition to is-a and part-of, axioms to formalize
  the definitions and relations.
• An explicit specification of a conceptualization

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Ontology

• Taxonomy and ontology are often interchangeably
  used, however they are fundamentally different.
• Taxonomy classifies objects in a domain in
  hierarchical structure
• give exact names for everything in a specified
  domain
• show which things are parts of other things
• Ontology offers more by expressing meaningful
  content within a specified domain of interest.
• Has strict, formal rules (a "grammar") about
  those relationships that let us make meaningful,
  precise statements about our entities/relationship
  s
• A formal ontology is hence a controlled
  vocabulary expressed in an ontology
  representation language

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Meta-model

• Data about data
• Facilitate the understanding, characteristics,
  and management usage of data
• An explicit model of the constructs and rules
  needed to build specific models within a domain
  of interest
• A valid meta-model is an ontology, but not all
  ontologies are modeled explicitly as meta-models
• Schema is Metadata

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Power Distribution System Asset Categorization

• Provide all key attributes of network assets,
  either concrete or abstract, operational stresses
  and external environments for determining asset
  conditions and failure probability
• Provide all key attributes to deduce asset costs
• Provide all associated social and environment
  factors that influence decision of asset
  investment
• This information is modeled into classes and
  attributes as well as class relationships using
  the common information model (CIM) specification

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UML

• Unified Modeling Language

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Origins of UML

• Evolution of object-oriented technology-
• Develop and start using OOP language
• Use of OOAD in business process modeling,
  requirement analysis and software systems design
• UML was designed to bring together the best
  features of a number of analysis and design
  technologies and notations to produce and
  industrial standard.

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Emergence of UML
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What is UML?

• UML is a visual language that originally applied
  in developing software systems.
• Now is extended for using in other area like
  knowledge modeling.
• It is a specification language.
• it has a set of elements and a set of rules that
  determine how it can be used.
• Most of UML elements are graphical lines,
  rectangles, ovals and other shapes, and many of
  these graphical elements are labelled with words
  that provides additional information.

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Why use UML?

• The needs of modeling Modeling can be as
  straightforward as drawing a flowchart listing
  the steps carried out in business process.
• Readability brings clarityease of understanding.
  This involves knowing what a system is made up
  of, how it behaves, and so forth.
• Reusability is the byproduct of making a system
  readable. After a system has been modeled to make
  it easy to understand, we tend to identify
  similarities or redundancy, be they in terms of
  functionality, features, or structure.
• The underline is standardization.

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UML Concepts

• UML is used to
• Show main functions and boundaries in a system
  using use cases and actors.
• Illustrate use case realizations using
  interaction diagrams.
• Represent a static structure of a system using
  class diagrams.
• Modelling object behaviour using state diagrams.
• Show implementation of the physical architecture
  using component and deployment diagrams.
• Enhance the functionality using stereotypes.

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UML Diagrams and Elements

• Use case diagrams
• Static structural diagrams
• Class, object
• Interaction diagrams
• Sequence, collaboration
• State diagrams
• Activity diagrams
• Implementation diagrams
• Packages, Components, Deployment

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Use Cases Diagram

• Use cases diagrams describes the behavior of the
  target system from an external point of view. Use
  cases describe "the meat" of the actual
  requirements.
• Use cases A use case describes a sequence of
  actions that provide something of measurable
  value to an actor and is drawn as a horizontal
  ellipse.
• Actors An actor is a person, organization, or
  external system that plays a role in one or more
  interactions with your system. Actors are drawn
  as stick figures.
• Associations  Associations between actors and
  use cases are indicated by solid lines. An
  association exists whenever an actor is involved
  with an interaction described by a use case

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Use Cases Diagram
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Class Diagram

• Class diagrams show the classes of the system,
  their inter-relationships, and the operations and
  attributes of the classes
• Explore domain concepts in the form of a domain
  model.
• Analyze requirements in the form of a
  conceptual/analysis model
• Depict the detailed design of object-oriented or
  object-based software

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Class Diagram
Class name
Person
Attributes
attribute name type
Operations
operation name(parameter type) result type
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Object Diagram

• Object diagrams (instance diagrams), are useful
  for exploring real world examples of objects and
  the relationships between them. It shows
  instances instead of classes. They are useful for
  explaining small pieces with complicated
  relationships, especially recursive
  relationships.

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Class and Objects
City
Name String default
Country String default
Population integer default
setName (s String deault)
setPopulation(p integer default)
ltltinstanceOfgtgt
ltltinstanceOfgtgt
ltltinstanceOfgtgt
New York City
Sydney City
London City
Name London
Name New York
Name Sydney
Country USA
Country Australia
Country UK
Population 2,324,320
Population 5,734,012
Population 3,536,000
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Sequence Diagram

• Sequence diagrams models the collaboration of
  objects based on a time sequence. It shows how
  the objects interact with others in a particular
  scenario of a use case.

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Sequence Diagram
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Collaboration Diagram

• Collaboration (Communication) diagrams used to
  model the dynamic behavior of the use case. When
  compare to Sequence Diagram, the Communication
  Diagram is more focused on showing the
  collaboration of objects rather than the time
  sequence.

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Collaboration Diagram
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State Diagram

• State diagrams can show the different states of
  an entity also how an entity responds to various
  events by changing from one state to another. The
  history of an entity can best be modeled by a
  finite state diagram.

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State Diagram
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Activity Diagram

• Activity diagrams helps to describe the flow of
  control of the target system, such as the
  exploring complex business rules and operations,
  describing the use case also the business
  process. It is object-oriented equivalent of flow
  charts and data-flow diagrams (DFDs).

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Activity Diagram
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Packages Diagram

• Package diagrams simplify complex class diagrams,
  it can group classes into packages. A package is
  a collection of logically related UML elements.
  Packages are depicted as file folders and can be
  used on any of the UML diagrams.

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Packages Diagram
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Components Diagram

• Component diagrams shows the dependencies among
  software components, including the classifiers
  that specify them (for example implementation
  classes) and the artifacts that implement them
  such as source code files, binary code files,
  executable files, scripts and tables.

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Components Diagram
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Deployment Diagram

• Deployment diagram depicts a static view of the
  run-time configuration of hardware nodes and the
  software components that run on those nodes.
  Deployment diagrams show the hardware for your
  system, the software that is installed on that
  hardware, and the middleware used to connect the
  disparate machines to one another.

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Deployment Diagram
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UML Class Diagrams and Relationships

• How would you draw a family tree? The steps you
  would take would be
• Identify the main members of the family
• Determine how they are related to each other
• Identify the characteristics of each family
  member
• Find relations among family members
• Decide the inheritance of personal traits and
  characters

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UML Class Diagrams and Relationships

• By definition, a class diagram is a diagram
  showing a collection of classes and interfaces,
  along with the collaborations and relationships
  among classes and interfaces.
• A class diagram consists of a group of classes
  and interfaces reflecting important entities of
  the business domain of the system being modeled,
  and the relationships between these classes and
  interfaces.
• A class diagram is a pictorial representation of
  the detailed system design.

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Elements of a Class Diagram
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UML Class Relationships
Relation Symbol Description
Association When two classes are connected to each other in any way, an association relation is established. For example A "student studies in a college" association can be shown as
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UML Class Relationships
Relation Symbol Description
Multiplicity An example of this kind of association is many students belonging to the same college. Hence, the relation shows a star sign near the student class (one to many, many to many, and so forth kind of relations).
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UML Class Relationships
Relation Symbol Description
Directed Association Association between classes is bi-directional by default. You can define the flow of the association by using a directed association. The arrowhead identifies the container-contained relationship.
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UML Class Relationships
Relation Symbol Description
Reflexive Association No separate symbol. An example of this kind of relation is when a class has a variety of responsibilities. For example, an employee of a college can be a professor, a housekeeper, or an administrative assistant.
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UML Class Relationships
Relation Symbol Description
Aggregation When two classes are When a class is formed as a collection of other classes, it is called an aggregation relationship between these classes. It is also called a "has a" relationship.
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UML Class Relationships
Relation Symbol Description
Composition Composition is a variation of the aggregation relationship. Composition connotes that a strong life cycle is associated between the classes.
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UML Class Relationships
Relation Symbol Description
Inheritance/ Generalization Also called an "is a" relationship, because the child class is a type of the parent class. Generalization is the basic type of relationship used to define reusable elements in the class diagram. Literally, the child classes "inherit" the common functionality defined in the parent class.
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UML Class Relationships
Relation Symbol Description
Realization In a realization relationship, one entity (normally an interface) defines a set of functionalities as a contract and the other entity (normally a class) "realizes" the contract by implementing the functionality defined in the contract..
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Other Terms for Annotations of Class Diagrams

• Responsibility of a class It is the statement
  defining what the class is expected to provide.
• Stereotypes It is an extension of the existing
  UML elements it allows you to define new
  elements modeled on the existing UML elements.
  Only one stereotype per element in a system is
  allowed.
• Vocabulary The scope of a system is defined as
  its vocabulary.
• Analysis class It is a kind of a stereotype.
• Boundary class This is the first type of an
  analysis class. In a system consisting of a
  boundary class, the users interact with the
  system through the boundary classes.
• Control class This is the second type of an
  analysis class. A control class typically does
  not perform any business functions, but only
  redirects to the appropriate business function
  class depending on the function requested by the
  boundary class or the user.
• Entity class This is the third type of an
  analysis class. An entity class consists of all
  the business logic and interactions with
  databases.

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Put Them Together
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XML

• eXtensible Markup Language

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Evolution

• SGML (Standard Generalized Markup Language)
• ISO Standard, 1986, for data storage exchange
• Metalanguage for defining languages (through
  DTDs)
• A famous SGML language HTML!!
• Separation of content and display
• Used in U.S. gvt. contractors, large
  manufacturing companies, technical info.
  Publishers,...
• SGML reference is 600 pages long
• XML (eXtensible Markup Language)
• W3C (World Wide Web Consortium) --
  http//www.w3.org/XML/) recommendation in 1998
• Simple subset (80/20 rule) of SGML ASCII of
  the Web, Semantic Web.
• XML specification is 26 pages long

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Evolution

• Canonical XML
• normalization, equivalence testing of XML
  documents
• SML (Simple Markup Language)
• Reduce to the max No Attributes / No
  Processing Instructions (PI) / No DTD / No
  non-character entity-references / No CDATA marked
  sections / Support for only UTF-8 character
  encoding / No optional features
• XML Schema
• XML Schema definition language
• Back to complex
• Part I (Structures), Part II (Data Types), Part
  III aehm 0 (Primer)

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What is XML?

• XML is a universal format for structured
  documents and data.
• Can be understood using any (archaic CP/M)
  editor
• Can be parsed easily
• Contains its own structure (parse tree) in the
  data
• Allows separation of marked-up content from
  presentation (style sheets)
• As a self-describing format good for archival
  into the past - not bad for archival into the
  future
• XML uses a Document Type Definition (DTD) or an
  XML Schema to describe the data
• XML with a DTD or XML Schema is designed to be
  self-descriptive

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Simple XML Example

• lt?xml version1.0 encodingwindows-874?gt
• ltnotegt
• lttogt Tom lt/togt
• ltfromgt Jane lt/fromgt
• ltheadinggt Reminder lt/headinggt
• ltbodygt Meeting at 9.00 AMlt/bodygt
• lt/notegt

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Why Is XML Important?

• Plain Text
• Easy to edit
• Useful for storing small amounts of data
• Possible to efficiently store large amounts of
  XML data through an XML front end to a database
• Data Identification
• Tell you what kind of data you have
• Can be used in different ways by different
  applications

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Why Is XML Important?

• Stylability
• Inherently style-free
• XSL---Extensible Stylesheet Language
• Different XSL formats can then be used to display
  the same data in different ways
• Inline Reusabiliy
• Can be composed from separate entities
• Modularize your documents without resorting to
  links

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Why Is XML Important?

• Linkability -- XLink and XPointer
• Simple unidirectional hyperlinks
• Two-way links
• Multiple-target links
• Expanding links
• Easily Processed
• Regular and consistent notation
• Vendor-neutral standard
• Hierarchical
• Faster to access
• Easier to rearrange

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XML Building Blocks

• Element
• Delimited by angle brackets
• Identify the nature of the content they surround
• General format ltelementgt lt/elementgt
• Empty element lt/empty-Elementgt
• Attribute
• Name-value pairs that occur inside start-tags
  after element name, like
• ltelement attributevaluegt

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XML Building blocks--Prolog

• The part of an XML document that precedes the XML
  data
• Includes
• A declaration version , encoding, standalone
• An optional DTD (Document Type Definition )
• Example
• lt?xml version"1.0" encoding"ISO-8859-1"
  standalone"yes"?gt

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XML Syntax

• All XML elements must have a closing tag
• XML tags are case sensitive
• All XML elements must be properly nested
• All XML documents must have a root tag
• Attribute values must always be quoted
• With XML, white space is preserved
• With XML, a new line is always stored as LF
• Comments in XML
• lt!-- This is a comment --gt

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XML is Based on Markup
Markup indicates structure and semantics

• ltbibliographygt
• ltpaper ID "object-fusion"gt
• ltauthorsgt
• ltauthorgtY.Papakonstantinoult/authorgt
• ltauthorgtS. Abiteboullt/authorgt
• ltauthorgtH. Garcia-Molinalt/authorgt
• lt/authorsgt
• ltfullPaper source"fusion"/gt
• lttitlegtObject Fusion in Mediator
  Systemslt/titlegt
• ltbooktitlegtVLDB 96lt/booktitlegt
• lt/papergt
• lt/bibliographygt

Decoupled from presentation
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XML Elements

• XML Elements are Extensible
• XML documents can be extended to carry more
  information
• XML Elements have Relationships
• Elements are related as parents and children
• Elements have Content
• Elements can have different content types
  element content, mixed content, simple content,
  or empty content and attributes
• XML elements must follow the naming rules

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XML as Labeled Ordered Trees

• can also represent
• relational and
• object-oriented data

ltbibliographygt ltpaper ...gt ltauthorsgt
ltauthorgtYannislt/authorgt ltauthorgtSergelt/autho
rgt ... lt/authorsgt lttitlegtObject
Fusionlt/titlegt ... lt/papergt lt/bibliographygt
? semistructured data ? labeled trees/graphs
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Elements and their Content
Element Content
element name
ltbibliographygt ltpaper ID"object-fusion"gt
ltauthorsgt ltauthorgtY.Papakonstantinoult/author
gt ltauthorgtS. Abiteboullt/authorgt
ltauthorgtH. Garcia-Molinalt/authorgt lt/authorsgt
ltfullPaper source"fusion"/gt
lttitlegtObject Fusion in Mediator Systemslt/titlegt
ltbooktitlegtVLDB 96lt/booktitlegt
lt/papergt lt/bibliographygt
element
Empty Element
Character content
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XML Attributes

• Located in the start tag of elements
• Provide additional information about elements
• Often provide information that is not a part of
  data
• Must be enclosed in quotes
• Should I use an element or an attribute?
• metadata (data about data) should be stored as
  attributes, and that data itself should be stored
  as elements

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Element Attributes
Attribute name
ltbibliographygt ltpaper ID"object-fusion"gt
ltauthorsgt ltauthorgtY.Papakonstantinoult/author
gt ltauthorgtS. Abiteboullt/authorgt
ltauthorgtH. Garcia-Molinalt/authorgt lt/authorsgt
ltfullPaper source"fusion"/gt
lttitlegtObject Fusion in Mediator Systemslt/titlegt
ltbooktitlegtVLDB 96lt/booktitlegt
lt/papergt lt/bibliographygt
Attribute Value
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XML Validation

• "Well Formed" XML document
• correct XML syntax
• "Valid" XML document
• well formed
• Conforms to the rules of a DTD (Document Type
  Definition)
• XML DTD
• defines the legal building blocks of an XML
  document
• Can be inline in XML or as an external reference
• XML Schema
• an XML based alternative to DTD, more powerful
• Support namespace and data types

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Displaying XML

• XML documents do not carry information about how
  to display the data
• We can add display information to XML with
• CSS (Cascading Style Sheets)
• XSL (eXtensible Stylesheet Language) --- preferred

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XML Specification

• XML Document Type Definitions (DTDs)
• define the structure of "allowed" documents
  (i.e., valid written a DTD)
• database schema
• improve query formulation, execution, ...
• XML Schema
• defines structure and data types
• allows developers to build their own libraries of
  interchanged data types
• XML Namespaces
• identify your vocabulary

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Document Type Definitions (DTD)
Define and Constrain Element Names Structure
lt!element bibliography papergt lt!element paper
(authors, fullPaper?, title, booktitle)gt lt!element
authors authorgt lt!element author
(PCDATA)gt lt!element fullPaper EMPTYgt lt!element
title (PCDATA)gt lt!element booktitle
(PCDATA)gt lt!attlist fullPaper source ENTITY
REQUIREDgt lt!attlist paper ID IDgt
Element Type Declaration
Attribute List Declaration
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Document Type Definitions (DTD)
Authors followed by optional fullpaper, followed
by title, followed by booktitle
Sequence of 0 or more paper
lt!element bibliography papergt lt!element paper
(authors, fullPaper?, title, booktitle)gt lt!element
authors authorgt lt!element author
(PCDATA)gt lt!element fullPaper
EMPTYgt lt!element title (PCDATA)gt lt!element
booktitle (PCDATA)gt lt!attlist fullPaper source
ENTITY REQUIREDgt lt!attlist paper ID IDgt
Sequence of 1 or more author
Character content
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Document Type Definitions (DTD)
ltperson ID"yannis"gt Yannis info lt/persongt
ltbibliographygt ltpaper ID"object-fusion"
ROLE"publication"gt ltauthorsgt ltauthor
authorRef"yannis"gt Y.Papakonstantinoult/authorgt
lt/authorsgt ltfullPaper source"fusion"/gt
lttitlegtObject Fusion in Mediator Systemslt/titlegt
ltrelated papers "semistructured-data"
"mediators"/gt lt/papergt lt/bibliographygt
Object Identity Attribute
CDATA (character data)
IDREF intradocument reference
Reference to external ENTITY
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XML Namespaces

• Namespace is a mapping between an element prefix
  and a URI
• cars is the prefix in this example,
• ltcarspart xmlnscarsURIgt
• URIs are not a pointer to information about the
  Namespace. They are just unique identifiers.
  You cannot resolve XML namespace URIs.

80
XML Namespaces

• An XML document may reference more than one
  schema
• A Namespace specifies which schema defines a
  given tag
• XML, like Java, uses qualified names
• This helps to avoid collisions between names
• Java myObject.myVariable
• XML myDTDmyTag
• Note that XML uses a colon () rather than a dot
  (.)
• If an XML processor is not namespace-aware, the
  colon is just part of the name

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Namespaces and URIs

• A namespace is defined as a unique string
• To guarantee uniqueness, typically a URI (Uniform
  Resource Indicator) is used, because the author
  owns the domain
• It doesn't have to be a real URI it just has
  to be a unique string
• Example http//www.matuszek.org/ns
• There are two ways to use namespaces
• Declare a default namespace
• Associate a prefix with a namespace, then use the
  prefix in the XML to refer to the namespace

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Namespace Syntax

• In any start tag you can use the reserved
  attribute name xmlns
• ltbook xmlns"http//www.matuszek.org/ns"gt
• This namespace will be used as the default for
  all elements up to the corresponding end tag
• You can override it with a specific prefix
• You can use almost this same form to declare a
  prefix
• ltbook xmlnsdave"http//www.matuszek.org/ns"gt
• Use this prefix on every tag and attribute you
  want to use from this namespace, including end
  tags--it is not a default prefix
• ltdavechapter davenumber"1"gtTo
  Beginlt/davechaptergt
• You can use the prefix in the start tag in which
  it is defined
• ltdavebook xmlnsdave"http//www.matuszek.org/ns
  "gt

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Namespaces and DTD

• Here is a sample Namespace specification within a
  DTD.
• lt!ELEMENT title ...gt
• lt!ATTLIST title xmlns CDATA FIXED
  ttp//www.person.com"gt
• lt!ELEMENT persontitle ...gt
• lt!ATTLIST persontitle
• xmlnsperson CDATA FIXED "http//www.person.c
  om"gt

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XML Schema

• People are dissatisfied with DTDs due to-
• It's a different syntax
• You write your XML (instance) document using one
  syntax and the DTD using another syntax --gt
  bad, inconsistent
• Limited datatype capability
• DTDs support a very limited capability for
  specifying datatypes. You can't, for example,
  express "I want the ltelevationgt element to hold
  an integer with a range of 0 to 12,000"
• Desire a set of datatypes compatible with those
  found in databases
• DTD supports 10 datatypes XML Schemas supports
  44 datatypes

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What is XML Schema?

• A grammar definition language
• Like DTDs but better
• Uses XML syntax
• Defined by W3C
• Primary features
• Datatypes
• e.g. integer, float, date, etc
• More powerful content models
• e.g. namespace-aware, type derivation, etc
• A schema is a collection of
• type definitions
• simple type
• complex type (contains element or attribute)
• element declarations

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Schema Terminology

• Schema a formal description for the structure
  and allowed content of a set of data (esp. in
  databases)
• XML Schema is often used for each of 1. XML
  Schema, the W3C Rec. that defines 2. XML
  Schema Definition Language (XSDL), an XML-based
  markup language for expressing ... 3. schema
  documents, each of which describes a schema (DTD)
  for a set of XML document instances

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Advantages of XSDL

• XML syntax
• schema documents easier to manipulate by programs
  (than the special DTD syntax)
• Compatibility with namespaces
• can validate documents using declarations from
  multiple sources
• Content datatypes
• 44 built-in datatypes (including primitive Java
  datatypes, datatypes of SQL, and XML attribute
  types)
• mechanisms to derive user-defined datatypes

88
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89
Advantages of XSDL

• Independence of element names and content types
  Compare with
• DTDs 1-to-1 correspondence btw. element type
  names and their content models
• CFGs 1-to-1 correspondence btw. nonterminals and
  their productions
• For example, could define titles of people as
  Mr./Mrs./Ms. and titles of chapters as
  strings

90
Advantages of XSDL

• Support for schema documentation
• element annotation with sub-elements
  documentation (for human readers) and
• appInfo (for applications)
• Ability to specify uniqueness and keys within
  selected parts of document
• for example, that titles of chapters should be
  unique

91
Disadvantages of XSDL

• Complexity of XSDL (esp. of Rec. Part 1!)
• gt a long learning curve
• Possible immaturity of implementations (?)
• W3C XML Schema Web site mentions a dozen of tools
  or processors (http//www.w3.org/XML/SchemaTools,
  March 2002)
• Open-source Apache XML parsers (Xerces C 1.7.0
  and Xerces Java 1.4.4) seem reasonable
  implementations, but also document
  limitations/problems in their XML Schema support

92
Highlights of XML Schemas

• XML Schemas are a tremendous advancement over
  DTDs
• Enhanced datatypes
• 44 versus 10
• Can create your own datatypes
• Example "This is a new type based on the string
  type and elements of this type must follow this
  pattern ddd-dddd, where 'd' represents a digit".
• Written in the same syntax as instance documents
• less syntax to remember
• Object-oriented'ish
• Can extend or restrict a type (derive new type
  definitions on the basis of old ones)
• Can express sets, i.e., can define the child
  elements to occur in any order
• Can specify element content as being unique (keys
  on content) and uniqueness within a region
• Can define multiple elements with the same name
  but different content
• Can define elements with nil content
• Can define substitutable elements - e.g., the
  "Book" element is substitutable for the
  "Publication" element.

93
Example DTD
lt!ELEMENT note (to, from, heading,
body)gt lt!ELEMENT to (PCDATA)gt lt!ELEMENT from
(PCDATA)gt lt!ELEMENT heading (PCDATA)gt lt!ELEMENT
body (PCDATA)gt
note.dtd
94
Example XML?DTD
lt?xml version"1.0"?gt lt!DOCTYPE note
SYSTEM "http//www.w3schools.com/dtd/note.dtd"gt lt
notegt lttogtTovelt/togt ltfromgtJanilt/fromgt ltheadinggtRem
inderlt/headinggt ltbodygtDon't forget me this
weekend!lt/bodygt lt/notegt
note.xml
95
Example XML Schema
lt?xml version"1.0"?gt ltxsschema
xmlnsxs"http//www.w3.org/2001/XMLSchema" targ
etNamespace"http//www.w3schools.com" xmlns"ht
tp//www.w3schools.com" elementFormDefault"qual
ified"gt ltxselement name"note"gt
ltxscomplexTypegt ltxssequencegt ltxseleme
nt name"to" type"xsstring"/gt ltxselement
name"from" type"xsstring"/gt ltxselement
name"heading" type"xsstring"/gt ltxselement
name"body" type"xsstring"/gt
lt/xssequencegt lt/xscomplexTypegt lt/xselementgt
lt/xsschemagt
note.xsd
96
Example XML?XML Schema
lt?xml version"1.0"?gt ltnote xmlns"http//www.w3s
chools.com" xmlnsxsi"http//www.w3.org/2001/XM
LSchema-instance" xsischemaLocation"http//www
.w3schools.com note.xsd"gt lttogtTovelt/togt ltfromgtJani
lt/fromgt ltheadinggtReminderlt/headinggt ltbodygtDon't
forget me this weekend!lt/bodygt lt/notegt
note.xml
97
RDF

• Resource Description Framework

98
Motivation for RDF

• RDF and Metadata
• Scenario 1 The library
• Lookup system search properties include author,
  title, subject etc.
• Scenario 2 The video store
• Lookup system search properties include
  directors, actors, etc.
• The common thread
• Metadata information about information

99
Motivation for RDF

• What about the Web?
• One big library, need call number to get things
  without a search
• Has hardly any metadata, HTML
• Yahoo
• Has metadata based lookup facility, uses human
  generated subject categories and site labels
• Library example to illustrate need for metadata

100
What is RDF?

• RDF stands for Resource Description Framework
• RDF is a framework for describing resources on
  the web
• RDF provides a model for data, and a syntax so
  that independent parties can exchange and use it
• RDF is designed to be read and understood by
  computers
• RDF is not designed for being displayed to people
  
• RDF is written in XML
• RDF is a part of the W3C's Semantic Web Activity
• RDF is a W3C Recommendation

101
What is RDF?

• Describe relationships and attributes of
  (Internet) resources, i.e. advanced metadata
• Based on Directed Labelled Graphs (DLG) and
  classical Information Analysis
• Also represented in XML, N3, N-Triple
• Attributes and Relation types may be defined by
  XML Namespaces, e.g. Dublin Core
• A general method to decompose knowledge into
  small pieces with some rules about semantics or
  meaning of those pieces
• Designed for knowledge, not data, means RDF is
  particularly concerned with meaning

102
RDF and XML

• RDF is an implementation of XML
• Why not just use XML?
• XML falls apart on the scalability design goal.
• There are two problems
• Order of elements important unnatural in
  metadata, also expensive in practice
• Representation of XML documents in memory trees
  difficult to manage when large
• XML unequalled as an exchange format on the Web,
  but it doesnt provide a metadata framework

103
Uses of RDF

• Resource Discovery to provide better search
  engine capabilities
• Cataloging for describing the content and
  content relationships
• Intelligent software agents to facilitate
  knowledge sharing exchange
• Content rating in describing collections of
  pages that represent a single logical document

104
Uses of RDF

• Describing intellectual property rights
• Privacy preferences expression of a user as
  well as the privacy polices of a Web site
• Web of Trust RDF with digital signatures will
  be key to building the Web of Trust for
  electronic commerce, collaboration, and other
  applications.

105
RDF Components

• Formal data model
• Syntax for interchange of data
• Schema Type system (schema model)
• Syntax for machine-understandable schemas
• Query and profile protocols

106
RDF Data Model

• Imposes structural constraints on the expression
  of application data models
• for consistent encoding, exchange and processing
  of metadata
• Enables resource description communities to
  define their own semantics
• Provides for structural interoperability

107
RDF Data Model

• Directed labelled graphs
• Model elements
• Statement Resource (Subject) Property
  (Predicate) Value (Object)
• Resource anything that can be identified,
  identified by a URI.
• Property specific aspect, characteristic,
  attribute, or relation used to describe a
  resource
• URI verbose name for Resource, can be http, urn,
  tag types
• Value

108
RDF Elements

• Subject source of relationship
• Always a resource
• Predicate labeled arc
• Always a resource
• Object relationships destination
• Resource or literal
• Subject and Predicates are first-class objects
• Which means they can be used as subjects or
  objects of other statements

109
RDF Model Primitives
Resource
Property
Value
110
RDF Model
Resource
Author
Paul
111
RDF Syntax

• RDF Model defines a formal relationships among
  resources, properties and values
• Syntax is required to...
• Store instances of the model into files
• Communicate files from one application to another
• W3C XML eXtensible Markup Language
• http//www.w3.org/XML

112
RDF Model Example
URIR
Title
RDF Presentation
Creator
Paul Miller
113
RDF Syntax Example
URIR
Title
RDF Presentation
Creator
Paul Miller
ltRDF xmlns http//www.w3.org/TR/WD-rdf-syntax
xmlnsdc http//purl.org/dc/element
s/1.0/gt ltDescription about URIRgt
ltdcTitlegt RDF Presentation lt/dcTitlegt
ltdcCreatorgt Paul Miller lt/dcCreatorgt
lt/Descriptiongt lt/RDFgt
114
RDF Model Example
URIR
Title
RDF Presentation
Creator
Paul Miller
115
RDF Syntax Example
ltRDF xmlns http//www.w3.org/TR/WD-rdf-syntax
xmlnsdc http//purl.org/dc/element
s/1.0/ xmlnsbib http//www.bib.org
/personsgt ltDescription about URIRgt
ltdcTitlegt RDF Presentation lt/dcTitlegt
ltdcCreatorgt ltDescriptiongt
ltbibNamegt Paul Miller lt/bibNamegt
ltbibEmailgt p.miller_at_ukoln.ac.uk lt/bibEmailgt
ltbibAff resource http//www.ukoln.ac.uk
/gt lt/Descriptiongt lt/dcCreatorgt
lt/Descriptiongt lt/RDFgt
116
RDF Schema

• RDFS or RDF Schema is an extensible knowledge
  representation language, providing basic elements
  for the description of ontologies, otherwise
  called RDF vocabularies, intended to structure
  RDF resources. The first version was published by
  W3C in April 1998, and the final W3C
  recommendation was released in February 2004.
  Main RDFS components are included in the more
  expressive language OWL.
• RDFS is also written in XML.

117
RDF Schema

• RDF describes resources with classes, properties,
  and values.
• In addition, RDF also need a way to define
  application -specific classes and properties.
  Application-specific classes and properties must
  be defined using extensions to RDF RDF Schema
• RDF Schema does not provide actual
  application-specific classes and properties.
• Instead RDF Schema provides the framework to
  describe application-specific classes and
  properties
• Classes in RDF Schema is much like classes in
  object oriented programming languages. This
  allows resources to be defined as instances of
  classes, and subclasses of classes

118
RDF Schema

• Basic vocabulary to describe RDF vocabularies
• Defines properties of the resources (e.g., title,
  author, subject, etc)
• Defines kinds of resources being describes
  (books, Web pages, people, etc)
• XML Schema gives specific constraints on the
  structure of an XML document
• RDF Schema provides information about the
  interpretation of the RDF statements

119
RDFS / RDF Classes
Class
Resource
Datatype
Container
Literal
Property
List
Statement
Alt
Bag
Seq
XMLLiteral
ContainerMembershipProperty
120
RDFS / RDF Properties
Element Domain Range Description
rdfsdomain Property Class The domain of the resource
rdfsrange Property Class The range of the resource
rdfssubPropertyOf Property Property The property is a sub property of a property
rdfssubClassOf Class Class The resource is a subclass of a class
rdfscomment Resource Literal The human readable description of the resource
rdfslabel Resource Literal The human readable label (name)  of the resource
rdfsisDefinedBy Resource Resource The definition of the resource
rdfsseeAlso Resource Resource The additional information about the resource
rdfsmember Resource Resource The member of the resource
rdffirst List Resource  
rdfrest List List  
rdfsubject Statement Resource The subject of the resource in an RDF Statement
rdfpredicate Statement Resource The predicate of the resource in an RDF Statement
rdfobject Statement Resource The object of the resource in an RDF Statement
rdfvalue Resource Resource The property used for values
rdftype Resource Class The resource is an instance of a class
121
RDFS / RDF Attributes
Element Domain Range Description
rdfabout     Defines the resource being described
rdfDescription     Container for the description of a resource
rdfresource     Defines a resource to identify a property
rdfdatatype     Defines the data type of an element
rdfID     Defines the ID of an element
rdfli     Defines a list
rdf_n     Defines a node
rdfnodeID     Defines the ID of an element node
rdfparseType     Defines how an element should be parsed
rdfRDF     The root of an RDF document
xmlbase     Defines the XML base
xmllang     Defines the language of the element content
122
RDF Schema Example

• lt?xml version"1.0"?gt
• ltrdfRDF xmlnsrdf"http//www.w3.org/1999/02/2
  2-rdf-syntax-ns"
• xmlnsrdfs"http//www.w3.org/2000/01/
  rdf-schema"gt
• ltrdfsClass rdfID"Person"gt
• ltrdfscommentgtPerson Classlt/rdfscommentgt
• ltrdfssubClassOf
• rdfresource"http//www.w3.org/1999/02/
  22-rdf-syntax-nsResource"/gt
• lt/rdfsClassgt
• ltrdfsClass rdfID"Student"gt
• ltrdfscommentgtStudent Classlt/rdfscommentgt
• ltrdfssubClassOf rdfresource"Person"/gt
• lt/rdfsClassgt
• ltrdfsClass rdfID"Teacher"gt
• ltrdfscommentgtTeacher Classlt/rdfscommentgt
• ltrdfssubClassOf rdfresource"Person"/gt
• lt/rdfsClassgt

123
RDF Schema Example (cont.)

• ltrdfsClass rdfID"Course"gt
• ltrdfscommentgtCourse Classlt/rdfscommentgt
• ltrdfssubClassOf rdfresource"http//www.w3.
  org/1999/02/22-rdf-syntax-nsResource"/gt
• lt/rdfsClassgt
• ltrdfProperty rdfID"teacher"gt
• ltrdfscommentgtTeacher of a
  courselt/rdfscommentgt
• ltrdfsdomain rdfresource"Course"/gt
  
• ltrdfsrange rdfresource"Teacher"/gt
  
• lt/rdfPropertygt
• ltrdfProperty rdfID"students"gt
• ltrdfscommentgtList of Students of a course
  in alphabetical orderlt/rdfscommentgt
• ltrdfsdomain rdfresource"Course"/gt
  
• ltrdfsrange rdfresource"http//www.w3.org/
  1999/02/22-rdf-syntax-nsSeq"/gt
• lt/rdfPropertygt
• ltrdfProperty rdfID"name"gt
• ltrdfscommentgtName of a Person or
  Courselt/rdfscommentgt

124
RDF (corresponded to previous schema)

• lt?xml version"1.0"?gt
• ltrdfRDF xmlnsrdf"http//www.w3.org/1999/02/2
  2-rdf-syntax-ns"
• xmlns"http//www.cs.rpi.edu/puninj/XMLJ/cou
  rse_schema.rdf"gt
• ltCourse rdfID"csci_2962"gt
• ltnamegtProgramming XML in Javalt/namegt
• ltteachergt
• ltTeacher rdfID"jp"gt
• ltnamegtJohn Puninlt/namegt
• lt/Teachergt
• lt/teachergt
• ltstudentsgt
• ltrdfSeqgt
• ltrdfligt
• ltStudent rdfID"er"gt
• ltnamegtElizabeth Robertslt/namegt
• lt/Studentgt
• lt/rdfligt
• ltrdfligt
• ltStudent rdfID"gl"gt

125
CIM

• Common Information Model

126
CIM Motivation

• Deregulation of the power industry worldwide
  requires utility companies share power system
  data Energy Management System- EMS
• Exchanging power systems data is always
  problematic due to use of proprietary formats
• Needs of open standard for representing power
  system components
• CIM defines a common model for describing the
  components in power systems for use in a common
  EMS

127
CIM Overview

• CIM is an information object-oriented model
  representing real-world objects found in
  transmission and distribution operation and
  management
• Enable integration of applications/systems
• Provides a common model behind all messages
  exchanged between systems
• Basis for defining information exchange models
• CIM provides a comprehensive, logical view of EMS
  information for
• Transmission network analysis
• Generation control
• SCADA
• Operator training simulation

128
CIM Overview

• Enable data access in a standard way
• Common language to navigate and access complex
  data structures in any database
• Provides a hierarchical view of data for browsing
  and access with no knowledge of actual logical
  schema
• Inspiration for logical data schemas (e.g., for
  an operational data store)
• Not tied to a particular applications view of
  the world
• But permits same model to be used by all
  applications to facilitate information sharing
  between applications
• Also provides consistent view of the world by
  operators regardless of which application user
  interface they are using

129
CIM Overview

• A data model to enable data transfer or
  integration in any domain where a common power
  system model is needed
• Model includes Classes, their Attributes, and
  Relationships to represent utility objects
• The Classes (Objects) are abstract and may are
  used in a wide variety of applications
• Useful
• As Foundation for Logical Data Base Schema
• To Define Component Interfaces
• Common Language for Data Exchange

130
Sample Power System Model
131
Role of CIM in Utility Enterprise

• Data preparation
• Provides common set of semantics and data
  representation regardless of source of data
• Improves data quality and enables data validation
• Data exchange
• Provides common language and format
• Provides common set of services for sharing data
• System integration
• Provides basis for a standards-based integration
  framework
• Web services payloads and Service Oriented
  Architecture (SOA)
• Enterprise Information Management
• Part of overall Enterprise Information Model
  relating to business processes/automation/manageme
  nt

132
Benefits of Using CIM Approach

• Data model driven solutions leads to
  interoperability
• Provides common semantics for information
  exchange between heterogeneous systems
• Used for CA to CA communications
• NERC mandated use of CIM and RDF Schema version
  for power system model exchange
• Provides for automatic generation of message
  payloads in XML
• Ensures common language for all messages defined
• Avoids proprietary message formats from vendors
  (based on internal schemas)
• Eliminates work of creating DTD for each message
• Alternative to EDI or CSV file formats

133
Benefits of Using CIM Approach

• Uses industry standard modeling notation
• UML, XML, RDF
• Permits software tool use for
• Defining and maintaining data models
• Single point of maintenance for changes
• Documenting data models
• Automatic generation of information payloads
• Automatically generate IDL, Java, C code

134
CIM Related Standards

• EPRI CCAPI The Electric Power Research
  Institute (EPRI) proposed an integration
  framework called control center application
  program interface for EMS data sharing
• IEC 61970-301 Common Information Model (CIM)
  base- A semantic model describing the components
  of a power system at an electrical level and the
  relationships between each component
• IEC 61970-501 Common Information Model Resource
  Description Framework (CIM RDF) schema
• IEC 61968-4 Interfaces for records and asset
  management
• IEC 61968-11 Extends the model to cover the
  other aspects of power system software data
  exchange such as asset tracking, work scheduling
  and customer billing

135
CIM Representation

• CIM is documented as a set of class diagrams
  using the Unified Modeling Language (UML)
• UML specifies CIM in an abstract manner that
  allows for open implementation
• There is no restriction to relational, object
  oriented or other modeling technologies
• The UML is a Diagramming Tool for CIM

136
An Example of CIM in UML
137
CIM Packages

• CIM consists of a number of packages
• Needed to make the model easier to design,
  understand and review
• Packages are grouped to be handled as a single
  standard document
• CIM - Common Information Model
• CIM Base in UML - IEC 61970 Part 301
• CIM Energy Scheduling, Reservations Financial -
  IEC 61970 Part 302CIM
• SCADA - IEC 61970 Part 303
• CIS - Component Interface Specifications
• GID - Generic Interface Definition
• CIM Model Exchange Format
• CIM RDF Schema (UML-gtRDF) - IEC 61970 Part 501
• CIM XML Model data Exchange Format - IEC 61970
  Part 552-4

138
CIM Base Part 301

• CIM Base in UML
• Package used for the Project
• Dashed lines indicate a dependency relationship
  between packages
• Arrow points from the dependent package to the
  package on which it has a dependency
• The Generation package is divided into two sub
  packages
• Production
• GenerationDynamics

139
Components of Part 301

• Core
• This package contains the core Naming,
  PowerSystemResource, EquipmentContainer, and
  ConductingEquipment entities shared by all
  applications plus common collections of those
  entities
• Not all applications require all the Core
  entities
• This package does not depend on any other
  package, but most of the other packages have
  associations and generalizations that depend on
  it
• Topology
• This package is an extension to the Core Package
• Specifies physical definition of how equipment is
  connected together
• In addition it models Topology, that is the
  logical definition of how equipment is connected
  via closed switches
• The Topology definition is independent of the
  other electrical characteristics

140
Components of Part 301

• Wires
• The Wires package is an extension to the Core and
  Topology packages
• Models information on the electrical
  characteristics of Transmission and Distribution
  networks
• This package is used by network applications such
  as State Estimation, Load Flow and Optimal Power
  Flow
• Outage
• This package is an extension to the Core and
  Wires packages
• Models information on the current and planned
  network configuration

141
Components of Part 301

• Protection
• This package is an extension to the Core and
  Wires packages
• Models information for pro