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                                                                   Exhibit 24(b)
                                  

                              C E R T I F I C A T E




         I, Jean M. Schmidt, do hereby certify that I am a duly elected,
qualified and acting Assistant Secretary of TRW Inc. ("TRW"), an Ohio
corporation; that attached hereto and marked as "Exhibit A" is a true and
correct copy of resolutions duly adopted by the Directors of TRW at a meeting
thereof duly called and held on February 4, 1997, at which meeting a quorum was
present and acting throughout; and that said resolutions have not been modified,
revoked or rescinded in any manner and are now in full force and effect.

         IN WITNESS WHEREOF, I have hereunto set my hand and have caused the
seal of TRW to be affixed hereto at Lyndhurst, Ohio this 18th day of March,
1997.









                                               /s/ Jean M. Schmidt
                                          ------------------------------
                                                Assistant Secretary



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                                                               Exhibit A        





RESOLVED that any officer or assistant officer of the Corporation is authorized
and empowered, for and on behalf of the Corporation, to prepare or cause to be
prepared, to execute and to file with the Securities and Exchange Commission,
Washington, D.C. (the "Commission"), the Corporation's Annual Report on Form
10-K for the year ended December 31, 1996, such other periodic reports as may be
required pursuant to the Securities Exchange Act of 1934, as amended (the
"Act"), amendments and exhibits to any of the foregoing and any and all other
documents to be filed with the Commission or elsewhere pertaining to such
reports, and to take other action deemed necessary and appropriate to effect the
filing of all such reports under the Act, including the execution of a power of
attorney evidencing the authority set forth herein; and

FURTHER RESOLVED that Martin A. Coyle,  James C. Diggs,  William A. Fullmer, 
Kathleen A. Weigand and J. Lawrence  Manning, Jr. and each of them is appointed
an attorney for the Corporation,  with full power of substitution and
resubstitution,  to execute  and file,  for and on  behalf  of the 
Corporation,  the  Annual  Report on  Form 10-K,  other  periodic  reports,
amendments  and  exhibits  to any of the  foregoing  and any and all other 
documents  to be filed with the  Commission  or elsewhere  pertaining to such
reports,  with full power and authority to take or cause to be taken all other
actions deemed  necessary and appropriate to effect the purposes of the
foregoing resolution.