NIAC

Contents 1 How to contact the NIAC 2 Current Members 3 Constitution 3.1 Terms of Reference 3.2 Membership 3.3 Organization 4 Procedures 4.1 Online Votes 4.2 Ratification of Instrument Definitions and Base Classes 5 Meetings 6 Action Items 7 Sub-Committees

How to contact the NIAC

You may contact the NIAC by sending an email to mailto://nexus-committee@nexusformat.org

Current Members

• Frederick Akeroyd, Rutherford Appleton Laboratory, UK (ISIS Representative, Technical Committee Chair)
• Stuart Campbell Spallation Neutron Source, USA (Executive Secretary - non voting)
• Bjorn Clausen, Los Alamos National Laboratory, USA
• Stephen Cottrell, Rutherford Appleton Laboratory, UK (Muon Representative)
• Matthias Drochner, Forschungzentrum Jülich, Germany
• Nick Hauser, Australian Nuclear Science and Technology Organisation, Australia (netCDF contact)
• Jens-Uwe Hoffmann, Helmholtz Zentrum Berlin (renamed HMI), Germany
• Pete Jemian, Advanced Photon Source, USA (Documentation Release Manager)
• Mark Könnecke, Paul Scherrer Institut, Switzerland (Chair)
• Raymond Osborn, Argonne National Laboratory, USA
• Peter Peterson, Spallation Neutron Source, USA
• Tobias Richter, Diamond Light Source, UK
• Armando Sole, European Synchrotron Radiation Facility, France
• Jiro Suzuki, KEK, Japan
• Ben Watts, Swiss Light Source, Switzerland
• Joachim Wuttke FRM II and JCNS, Germany

The expiration dates for the various members.

Constitution

Terms of Reference

The purpose of the NeXus International Advisory Committee is to supervise the development and maintenance of the NeXus common data format for neutron, x-ray, and muon science. This purpose includes, but is not limited to, the following activities.

1. To establish policies concerning the definition, use, and promotion of the NeXus format.
2. To ensure that the specification of the NeXus format is sufficiently complete and clear for its use in the exchange and archival of neutron, x-ray, and muon data.
3. To receive and examine all proposed amendments and extensions to the NeXus format. In particular, to ratify proposed instrument and group class definitions, to ensure that the data structures conform to the basic NeXus specification, and to ensure that the definitions of data items are clear and unambiguous and conform to accepted scientific usage.
4. To ensure that documentation of the NeXus format is sufficient, current, and available to potential users both on the internet and in other forms.
5. To coordinate with the developers of the NeXus Application Programming Interface to ensure that it supports the use of the NeXus format in the neutron, x-ray, and muon communities, and to promote other software development that will benefit users of the NeXus format.
6. To coordinate with other organizations that maintain and develop related data formats to ensure maximum compatibility.

The committee will meet at least once every calendar year according to the following plan:

• In years coinciding with the NOBUGS series of conferences (once every two years), members of the entire NIAC will meet as a satellite meeting to NOBUGS, along with interested members of the community.
• In intervening years, the executive officers of the NIAC will attend, along with interested members of the NIAC. This is intended to be a working meeting with a small group.

Membership

The NeXus International Advisory Committee will seek balanced representation of the international community. It will consist of at most one voting representative from each major neutron, synchrotron x-ray, and muon facility. Membership would normally be for a three year renewable term. Members will be nominated by each facility through the facility director and approved by the existing committee. Each member can appoint a substitute to attend a particular meeting.

The committee reserves the right to appoint additional members for a limited period to ensure balanced representation.

Organization

Accountability

The NeXus International Advisory Committee will ensure that their decisions are reported both on the NeXus web site and on the NeXus mailing list. Committee business will be conducted either through a mailing list, to which non-committee members can subscribe and whose archive will be available on the web, or through meetings, which will be advertised on the NeXus mailing list and which non-committee members may attend.

The NeXus International Advisory Committee will have the following executive officers:

• Chair to oversee committee deliberations
• Executive Secretary to coordinate meetings and online debates. The person that holds the position does not need to be an existing member of the NIAC, and does not vote unless he/she is a regular member.
• Technical Committee Chair with the responsibility to oversee the NeXus API. The tasks of the chair are to coordinate tests, manage and announce releases, and promote code from the contributed directory to the regular release build. The person that holds the position does not need to be an existing member of the NIAC, and does not vote unless he/she is a regular member.
• Definition Release Manager with the responsibility to oversee the release of NeXus definitions and documentation. The person that holds the position does not need to be an existing member of the NIAC, and does not vote unless he/she is a regular member.

All of these officers will be elected each year, effective at the end of the voting period set forth by the executive officers. The position of chair and executive secretary carry a term limit of three years.

Voting

Only members of the NeXus International Advisory Committee will be able to vote on specific proposals that come under the remit of the committee. However, all debates will be conducted publicly and non-committee members are both allowed and encouraged to participate.

Topics voted on will require a simple majority unless specifically challenged by a committee member. In the event of a challenge, the issue will be presented to the NeXus mailing list inviting comments for a period of one month. At the end of this period, the challenge can be overruled by a two thirds majority.

The constitution can only be changed by a two thirds majority of the NIAC.

Special Interest Groups

The NeXus International Advisory Committee will appoint editors to be in charge of particular groups that wish to specify instrument definitions or develop specialized uses of the NeXus format. The groups will establish their own mode of operation, but will be expected to consult widely with the community relevant to their work, and to refer back to the NeXus International Advisory Committee any matters that involve a change in the current NeXus specification. Specific proposals produced by these groups will be presented to the NeXus International Advisory Committee for comment and formal ratification.

Procedures

Online Votes

The NeXus wiki will be used to conduct online votes of current members of the NIAC. The procedure and an example vote are described here.

Ratification of Instrument Definitions and Base Classes

The NeXus format is defined as a series of XML files describing both the base classes and generic instruments that contain a subset of those classes. It is the role of the NeXus International Advisory Committee to ratify those base classes, and to approve modifications when they are proposed. This is the current procedure:

1. The current version of the instrument definitions and base classes shall be kept on the NeXus wiki so that people can post suggested modifications.
2. The Executive Secretary of the NIAC will review those changes at regular intervals, monthly or bimonthly. If in his or her judgment, a reasonable proposal has been made, the information will be forwarded to the NIAC mailing list for discussion. If the change is significant, or has implications for backward compatibility, the proposal will also be sent to the NeXus mailing list.
3. The members of NIAC have one month to make comments concerning the proposed changes, after which the Executive Secretary will formulate a proposal based both on the original suggestion and the subsequent debate, and send it to the mailing list.
4. This will be voted online as described above. At least two-thirds of the committee must vote. Changes will be approved by a majority of the whole committee.
5. The revised instrument definitions and base classes will then be posted to the NeXus SVN server.

Meetings

• NIAC 2012 NeXus Code Camp and NIAC Meeting, hosted by ISIS and Diamond at RAL, Oxfordshire, UK, September 2012
• NIAC 2011 NeXus Code Camp and NIAC Meeting, APS, October 2011 (minutes)
• NIAC 2010 NeXus Code Camp and NIAC Meeting, ORNL, October 2010 (minutes)
• October 16-18 2009 NeXus Code Camp, hosted by APS, Chicago (Evanston, Illinois) (no minutes)
• October 30-31, 2008 at ANSTO, Australia (minutes )
• September 24-26, 2007 at HMI, Berlin, Germany (online and pdf format minutes)
• October 5-6, 2006 at LBL, Berkeley, CA, USA (minutes)
• February 1-3, 2006 at ILL, Grenoble, France (minutes)
• April 26-28, 2005 at Bishops Lodge in Sante Fe, NM, USA (minutes)
• October 21-22, 2004 at PSI, Villigen, Switzerland (minutes)
• September 8-10, 2003 at Pasadena, CA, USA (minutes)

Action Items

Action Items for members of the NIAC that are not associated to one of the repositories.

Sub-Committees

• NeXus Technical sub-committee