The optimization of large trusses often leads to a nearly optimal solution, rather than a truly optimal design. In fact, the problem space for truss optimization grows exponentially with the size of the truss. Using the method of problem reduction, this paper demonstrates that truss optimization is in the set of NP-complete problems. Hence, the only practical techniques for solving the truss pr...

This paper presents a hybrid geometric modeling method to create CAD models of large-scale conformal cellular structures effectively and efficiently. Cellular material structures can be engineered at the mesoscopic scale for high performance and multifunctional capabilities. One type of cellular structure is conformal lightweight truss. A simple method of constructing models of uniform trusses ...

Engineering and horticultural research efforts aimed at developing an innovative, controlled environment, plant production system have been completed. In this production system, tomato plants are made transportable and each plant is allowed to produce only one truss of fruit. The main objective of this production system is to secure uninterrupted and predictable quantities of uniform quality to...

This paper shows the complementary roles of mathematical and engineering points of view when dealing with truss analysis problems involving systems of linear equations and inequalities. After the compatibility condition and the mathematical structure of the general solution of a system of linear equations is discussed, the truss analysis problem is used to illustrate its mathematical and engine...

Particle swarm optimization (PSO) algorithm is a heuristic optimization technique based on colony intelligence, developed through inspiration from social behaviors of bird flocks and fish schools. It is widely used in problems in which the optimal value of an objective function is searched. Geometrically nonlinear analysis of trusses is a problem of this kind. The deflected shape of the truss w...

The k-truss is a type of cohesive subgraphs proposed recently for the study of networks. While the problem of computing most cohesive subgraphs is NP-hard, there exists a polynomial time algorithm for computing k-truss. Compared with k-core which is also efficient to compute, k-truss represents the “core” of a k-core that keeps the key information of, while filtering out less important informat...

Frontal-impact airbag systems have the potential to provide a benefit to rear seat occupants by distributing restraining forces over the body in a manner not possible using belts alone. This study sought to investigate the effects of incorporating a belt-integrated airbag ("airbelt") into a rear seat occupant restraint system. Frontal impact sled tests were performed with a Hybrid III 50th perc...

Recent studies suggest that the softerror rate in microprocessor logic is likely to become a serious reliability concern by 2010. Detecting soft errors in the processor’s core logic presents a new challenge beyond what error-detecting and correcting codes can handle. Currently, commercial microprocessor systems that require an assurance of reliability employ an error-detection scheme based on d...