Three Rivers Computer Corporation

The Three Rivers Computer Corporation (3RCC) was a spinoff from the Research Engineering Laboratory of the Computer Science Department of Carnegie-Mellon University, and was founded in May 1974 by Brian S. Rosen, James R. Teter, William H. Broadley, J. Stanley Kriz, D. Raj Reddy and Paul G. Newbury in Pittsburgh, Pennsylvania, USA to manufacture advanced technology computer displays, peripherals, and systems. Early products included: the GDP/2A Graphics Display processor with high speed vector generator capable of drawing in excess of 50,000 vectors at 60 Hz refresh rates; a CVD/2 Color Video Display System that displayed a full color raster scanned image with a unique data compression algorithm capable of full frame animation display; ADA-16 Analog to Digital and Digital to Analog convertors for high fidelity music and speech research, and a UMB-11 Unibus Monitor that was a low-cost test instrument for PDP-11 series minicomputers. In 1979, the company launched its principal products, a line of workstation computers called PERQ, which were single-user high performance workstations with the power of a medium-scale mainframe computer from that era coupled with a versatile graphics display. In the summer of 1980, the company divested itself of all activities other than those related to PERQ. From 1981 onwards, 3RCC developed and produced the PERQ jointly with ICL in the United Kingdom. 3RCC changed its name to PERQ Systems Corporation in 1984, but became insolvent in 1985.

Region connection calculus

The region connection calculus (RCC) is intended to serve for qualitative spatial representation and reasoning. RCC abstractly describes regions (in Euclidean space, or in a topological space) by their possible relations to each other. RCC8 consists of 8 basic relations that are possible between two regions:

From these basic relations, combinations can be built. For example, proper part (PP) is the union of TPP and NTPP.

Composition table

The composition table of RCC8 are as follows:

Examples

The RCC8 calculus is intended for reasoning about spatial configurations. Consider the following example: two houses are connected via a road. Each house is located on an own property. The first house possibly touches the boundary of the property; the second one surely does not. What can we infer about the relation of the second property to the road?

RCC2

Protein RCC2 also known as telophase disk protein of 60 kDa (TD-60) or RCC1-like protein TD-60 is a protein that in humans is encoded by the RCC2 gene.

Function

RCC2 has structural similarity to RCC1, and has been shown to have weak guanine nucleotide exchange factor (GEF) activity on the small GTPase Rac. TD-60 has also been shown to interact with the Chromosomal Passenger Complex (CPC), and to activate the catalytic component of the CPC, Aurora B, in the presence of microtubules.

References

Further reading