Computation of Surface Areas In GMSolid

When Applied to Combustion Chamber Design Analysis at General Motors, This Treebased Calculation Method Has Saved Time over the Boundary Representation Approach.     

Static Data Flow Analysis of PL/I Programs with the PROBE System

An experimental data flow analyzer for PL/I programs has been implemented within the PROBE system developed at the GM Research Laboratories. PROBE is an experimental software package that examines the internal structure of PL/I programs in order to expose error-prone design and programming features. This paper describes 1) the algorithms and data structures used by the data flow analyzer, 2) the salient aspects of PL/I usage in the analyzed production-level programs, and 3) the results of the data flow analysis.     

Using volume morphing to compensate shape distortions associated with injection molding

Manufacturing processes often produce parts with shapes that are distorted from the shapes specified in the CAD models created by designers. Volume morphing, a technique pioneered by Pierre Bézier in 1978 and by Sederberg and Parry in 1986, has been used quite successfully to alter tool-surface designs in order to compensate for shape distortions in manufacturing. FESHAPE, a computer software package created at the General Motors Research and Development Center, automatically modifies CAD models according to a finite set of displacement vectors. This article describes the basic methods of FESHAPE and their application to correct distortions produced by thermal stresses during injection molding.     

Malignant anorectal melanoma

Bone marrow cell responses to injections of nitrogen mustard, oncovin, procarbazine, hydrocortisone, and a regimen of all four drugs (MOPH) were evaluated in CRF1 and C57B1/6 mice by determining bone marrow cellularity and content of transplantable colony forming units (CFU) after treatment. The study was done to determine whether the combined regimen, which is widely used clinically in treatment of disseminated Hodgkin's disease, is more or less detrimental to the hemopoietic system than the same drugs used as single agents. Nitrogen mustard and procarbazine used clinically as single drugs are given in three and two times, respectively, greater doses than in the combined regimen. Hydrocortisone, given singly, was least toxic of the drugs, reducing the CFU/femur to 63% and 71% of control values. MOPH appeared slightly more toxic than hydrocortisone, resulting in 41% and 52% of the CFU/femur surviving, and was about equally as toxic as oncovin alone. Nitrogen mustard and procarbazine, administered as single drugs in high doses, were highly suppressive, resulting in only 10-19% survival of CFU/femur, whereas, reduced doses of the two drugs as used in the MOPH regimen spared 30-45% of the CFU/femur. Survival of CFU after MOPH treatment was three to four times greater than after high doses of nitrogen mustard or procarbazine alone. The component drugs of the combined regimen did not act on separate populations of stem cells to produce an additive effect but appeared to inactivate the same population of cells.