OVERVIEW:
=========

The basic idea of network builder is to represent knowledge sources
for speech recognizer in a generalized hierarchy. These knowledge
sources include language model, pronunciation model and HMM topologies
etc. Figure 1 shows a typical hierarchical structure for a continuous
digit speech recognizer. At the top level (word level), the language
model for a sentences with continuous digits is represented as a
digraph with loop back arc which allows any digit can follows the
other. In such a generalized hierarchical structure, each level can be
conceptually considered as the same. Phrases, words or phones are
simply symbols at different levels. Each level contains a list of
symbols Sij and a list of graphs Gik., where, i is the index of the
level, j is the index of the symbol and k is the index of the
graph. Each graph has at least two dummy vertices, the start vertex
and the terminal vertex both indicating the start and the end points
of the graph in a search space.


MAIN PANEL
==========

The main frame of isip_network_builder is divided into three
panels. The top-left panel labeled with Hierarchy shows the
generalized hierarchical structure of the model. The bottom-left panel
labeled with Graph List shows the list of graphs at current level. The
right panel is the drawing area which allows users to construct graphs
by inserting nodes and arcs. Here are the explanation of menu options:

File Menu: 
      New: Clears the current window, and open a blank file. 
      Open: Opens a existing network builder file. 
      Save: Saves the current file. 
      Save As: Saves the current file to a different file name. 
      Save All: Save both the language model file and the statistical model 
		file
      Close: Closes the current file. 
      Exit: Exits network builder. 

Hierarchy Menu: 
      Add Level: Adds a level to the hierarchy. 
      Delete Level: Removes the currently selected level from the hierarchy. 
      Check Levels: Checks the integrity of all the levels in the hierarchy.
      Symbols: Opens the symbol table for the current level. 

Graph Menu: 
      Insert Start: Inserts a start node, each graph must have a start node. 
      Insert Stop: Inserts a stop node, each graph must have a stop node. 
      Insert Node: Inserts a node into the current graph. 
      Insert Arc: Inserts an arc between two nodes. 
      Insert Self Arc: Inserts an self connecting arc. 
      Copy: Copies the selected node to the clipboard. 
      Cut: Copies and deletes the selected node. 
      Paste: Pastes the node from the clipboard. 
      Delete: Deletes the currently selected node. 
      Add Graph: Adds a graph to current level.
      Delete Graph: Deletes selected graph.
      Copy Graph: Copies the selected graph to the clipboard. 
      Paste Graph: Pastes the graph from the clipboard. 
      Set Equal Weights: Sets equal weights for all arcs.


FAQ
==========
1. How to change the weight of an arc ?
Right-click the arc to bring up a configuration window.

2. How to define the property of a symbol at a certain level ?
Click on the level first and then select Hierarchy --> Symbols from
the Menu option.

3. What is the difference of three different format ?  

The "NATIVE" format is the format used by this tool. If you store the
models in this format, all the information of the graphs will be
preserved. The "DIGRAPH" format can be used directly by
isip_recognizer. The graph in this format is stored as Directional
Graph called DiGraph. The structure of each graph is stored but the
original layout of each node in the graph is not stored. When you open
file in this format with the isip_network_builder, the
isip_network_builder will automatically set the layout of the graph
for you. The "JSGF" format can be also used directly by the
isip_recognizer. The graphs are stored in terms of JSGF grammars. The
layout information of graphs won't be stored in this format. However,
you can also open file in this format with isip_network_builder with
automatic layout.

SUPPORT
=======

The Transform Builder tool is developed by:

Institute for Signal and Information Processing (ISIP)

Department of Electrical and Computer Engineering
PO Box 9571, Mississippi State University
Mississippi State, MS 39762

Voice / Fax: (662) 325-8335
WWW: http://www.isip.msstate.edu/

Please direct you questions and comments to: help@isip.msstate.edu.

