Question: What company was the fifth-largest defense contractor in the world in 2015 and is part of the VITA working group?

<P0-S0> General Dynamics Corporation is an American aerospace and defense multinational corporation. <P0-S1>  Formed by mergers and divestitures, it is the world's fifth-largest defense contractor based on 2012 revenues. <P0-S2>  General Dynamics is headquartered in West Falls Church, Fairfax County, Virginia. <SEP> <P1-S0> HRB Systems Inc., now part of Raytheon Intelligence and Information Systems, is a defense contractor located in State College, Pennsylvania. <P1-S1>  The company was started by three scientists: Haller, Raymond, and Brown. <P1-S2>  Initially, the firm provided imagery support, then transitioned to signal analysis and processing. <P1-S3>  The company was acquired by Singer, and became known as HRB-Singer, one of the firms in the Singer Defense Systems Group, dealing with infrared reconnaissance techniques and equipments. <P1-S4>  It was physically located in east e Science Park, in State College. <P1-S5>  The company had a strong internal R&D effort which was quite successful. <P1-S6>  HRB-Singer provided signal processing equipment and expertise to the US Department of Defense and to international clients in Europe and Asia. <P1-S7>  In 1988, Singer sold off the Defense unit to corporate raider Paul Bilzerian, who sold each of the companies separately. <P1-S8>  HRB division was sold to Hadson Corporation for $137 million in cash and 2 million shares of Hadson common stock. <P1-S9>  HRB was subsequently acquired by E-Systems, and was downsized to a considerable degree. <P1-S10>  The company was later acquired by Raytheon. <SEP> <P2-S0> Northrop Grumman Corporation () is an American global aerospace and defense technology company formed by Northrop's 1994 purchase of Grumman. <P2-S1>  Northrop Grumman employs over 68,000 people worldwide. <P2-S2>  It reported revenues of $23.526 billion in 2015. <P2-S3>  The company was named as the fifth-largest defense contractor in the world in 2015. <P2-S4>  Northrop Grumman ranks No. 124 on the 2015 Fortune 500 list of America's largest corporations and ranks in the top ten military-friendly employers. <P2-S5>  It is headquartered in West Falls Church, Virginia. <SEP> <P3-S0> VPX was originally defined by American Logic Machines Inc (ALM) as a scalable backplane technology. <P3-S1>  The VPX3264, VPX3232 bridge chips and the scalable backplane were based on VPX. <P3-S2>  VPX technology was presented at bus&board (VITA) in 2004. <P3-S3>  ALM continues to build custom chipsets for clients including VME-to-PCIX, VME-to-Futurebus+ and other custom scalable backplane technologies. <P3-S4>  VPX, formerly known as VITA 46, is an ANSI standard (ANSI/VITA 46.0-2007) that provides VMEbus-based systems with support for switched fabrics over a new high speed connector. <P3-S5>  Defined by the VITA (VME International Trade Association) working group (composed of companies such as ADLINK, Aitech, Boeing, Curtiss-Wright, Elma Electronic, Extreme Engineering (X-ES), GE Intelligent Platforms, Kontron, Mercury Computer Systems, Pentek, Cornet Technology, Inc., and Northrop Grumman), it has been designed specifically with defense applications in mind, with an enhanced module standard that enables applications and platforms with superior performance. <P3-S6>  VPX retains VME's existing 6U and 3U Eurocard form factors, supporting existing PCI Mezzanine Card (PMC) and XMC mezzanines (PMC with high-speed serial fabric interconnect), and maintaining the maximum possible compatibility with VMEbus.