Changes between Version 4 and Version 5 of WikiStart


Ignore:
Timestamp:
10/12/06 00:59:06 (18 years ago)
Author:
gschadow
Comment:

--

Legend:

Unmodified
Added
Removed
Modified

  • WikiStart

    v4 v5  
    1818The Unified Code for Units of Measure is inspired by and heavily based on ISO 2955-1983, ANSI X3.50-1986, and HL7's extensions called ``ISO+''. The respective ISO and ANSI standards are both entitled Representation of [...] units in systems with limited character sets where ISO 2955 refers to SI and other units provided by ISO 1000-1981, while ANSI X3.50 extends ISO 2955 to include U.S. customary units. Because these standards carry the restriction of ``limited character sets'' in their names they seem to be of less value today where graphical user interface and laser printers are in wide-spread use, which is why the european standard ENV 12435 in its clause 7.3 declares ISO 2955 obsolete.
    1919
    20 ENV 12435 is dedicated exclusively to the communication of measurements between humans in display and print, and does not provide codes that can be used in communication between systems. It does not even provide a specification that would allow communication of units from one system to the screen or printer of another system. The issue about displaying units in the common style defined by the 9th Conférence Générale des Poids et Mesures (CGPM) in 1947 is not just the character set. Although The Unicode Standard and its predecessor ISO/IEC 10646 is the richest character set ever it is still not enough to specify the presentation of units because there are important typographical details such as superscripts, subscripts, roman and italics.1
     20ENV 12435 is dedicated exclusively to the communication of measurements between humans in display and print, and does not provide codes that can be used in communication between systems. It does not even provide a specification that would allow communication of units from one system to the screen or printer of another system. The issue about displaying units in the common style defined by the 9th Conférence Générale des Poids et Mesures (CGPM) in 1947 is not just the character set. Although The Unicode Standard and its predecessor ISO/IEC 10646 is the richest character set ever it is still not enough to specify the presentation of units because there are important typographical details such as superscripts, subscripts, roman and italics.^1^
    2121
    2222== Why is it needed? ==
    … …  
    4242The Unified Code for Units of Measures is very stable in content and has already been adopted by some standard organizations such as DICOM, HL7 and has been referenced as best practice by the Open Geospatial Consortium in their Web Map Service (WMS) and Geography Markup Language (GML) implementation specifications. We are still looking for the best way to establish this specification as a widely used industry standard. The official status and the affiliation may change during that process. However, we try to keep as much as possible of the specification freely available and redistributable to assure the maximum use and benefit. We would also like to keep this specification maintainable and flexible to updates. Although the initial version contains more than 250 terminal unit symbols (more than three times as many symbols as in ANSI X3.50), there are areas that are not covered completely yet.
    4343
    44 The specification is maintained electronically so that the printed version is guaranteed to contain consistent and tested data that is free from severe name conflicts or random errors. The full specification is now available as an HTML document (whereas it used to be only a PDF file). The PDF is still here for your convenience, however, the PDF is not updated at this time, hence it will slowly be outdated. The new XML format of the specification will soon enable us to make XML releases of the formal part of the specification, have better sorting and indexing capabilities, etc.
    45 
    46 A computer-readable XML file is now available which contains all the essential definitions.
     44The specification is maintained electronically so that the printed version is guaranteed to contain consistent and tested data that is free from severe name conflicts or random errors. The [http://aurora.regenstrief.org/~ucum/ucum.html full specification] is now available as an HTML document (whereas it used to be only a PDF file). The new XML format of the specification enabled us to make [http://aurora.regenstrief.org/~ucum/ucum-essence.xml XML releases of the formal part of the specification], have better sorting and indexing capabilities, etc.
    4745
    4846== IMPORTANT SPECIAL RELEASE NOTE ==
    … …  
    5856== More ==
    5957
    60 There is an open-source reference implementation, instantly usable as a Java applet, that is configured at runtime over the Internet with the latest release of The Unified Code for Units of Measures.
     58There is an open-source reference implementation, instantly usable as a [http://aurora.regenstrief.org/~schadow/units Java applet], that is configured at runtime over the Internet with the latest release of The Unified Code for Units of Measures.
    6159
    6260----------------------------------------------