n the Air Defense Systems Department, systems engineering is a way of thinking. More than a “process,” the systems perspective drives our approach to solving emerging air and missile defense problems as the threat becomes more advanced and the tactical environment more complex. This perspective and the requisite tools have evolved with the increasing complexity of those systems. In this article...

The superconducting proximity effect leads to strong modifications of the local density of states in diffusive or chaotic cavity Josephson junctions, which displays a phase-dependent energy gap around the Fermi energy. The so-called minigap of the order of the Thouless energy ETh is related to the inverse dwell time in the diffusive region in the limit ETh ∆, where ∆ is the superconducting ener...

Abstract The medium-thickness plate penetration enhanced behavior of coupled kinetic energy and chemical reactive fragment was investigated. A series experiments were conducted. After the experiments, High-speed photography images blackening at front compared. results show that enhancement penetrating is related to intensity deflagration plate. Division zones impacting proposed, combine dynamic...

The solution-space structure of the three-satisfiability problem (3-SAT) is studied as a function of the control parameter α (ratio of the number of clauses to the number of variables) using numerical simulations. For this purpose one has to sample the solution space with uniform weight. It is shown here that standard stochastic local-search (SLS) algorithms like average satisfiability (ASAT) e...

Polyurea elastomer is known to exhibit advantageous impact-mitigation characteristics and thus can improve the dynamic performance of various components structures. This study identifies mechanisms response thin metallic plates, covered by a frontal polyurea layer, using physically verified, custom material model for two-part implemented within finite-element-method framework. A linear increase...

an internal ballistics model has been developed for performance prediction of a solid propellant rocket motor. inthis model a 1-d unsteady euler equation with source terms is considered. the flow is assumed as a non-reacting mixture of perfect gases with space and time varying thermo physical properties. the governing equations in the combustion chamber are solved numerically by using the stege...

Aaron Karp is Senior Faculty Associate with the Graduate Programs in International Studies at Old Dominion University in Norfolk, Virginia. He is the author of Ballistic Missile Proliferation (Oxford University Press, 1996) and numerous articles that have appeared in such journals as International Security, Survival, and International Studies Quarterly. LESSONS OF IRANIAN MISSILE PROGRAMS FOR U...