Dynamic analysis using superelements for a large helicopter model

Using superelements (substructures), modal and frequency response analysis was performed for a large model of the Advanced Attack Helicopter developed for the U.S. Army. Whiffletree concept was employed so that the residual structure along with the various superelements could be represented as beam-like structures for economical and accurate dynamic analysis. A very large DMAP alter to the rigid format was developed so that the modal analysis, the frequency response, and the strain energy in each component could be computed in the same run

Linear systems analysis program, L224(QR). Volume 1: Engineering and usage

The QR computer program is described as well as its use in classical control systems analysis and synthesis (root locus, time response, and frequency response)

Status of ψ\psi (3686), ψ\psi (4040), ψ\psi (4160), Y (4260), ψ\psi (4415) and X (4630) charmonia like states

We examine the status of charmonia like states by looking into the behaviour of the energy level differences and regularity in the behaviour of the leptonic decay widths of the excited charmonia states. The spectroscopic states are studied using a phenomenological Martin-like confinement potential and their radial wave functions are employed to compute the di-leptonic decay widths. Their deviations from the expected behaviour provide a clue to consider them as admixtures of the nearby S and D states. The present analysis strongly favour \\backslash$psi \$ (3686) as admixture of $c \bar{c}$ (2S) and $c \bar{c}$g (4.1 GeV) hybrid, \\backslash$psi \$ (4040) and \$$\backslash$psi \$ (4160) as admixture states of charmonia (3S, 3D) states with mixing angle \$$\backslash$theta \$ = 11$^\circ$and 45$^\circ$respectively. We identify Y (4260) as a pure$c \bar{c}$(4S) state whose leptonic decay is predicted as 0.65 keV. While X(4630) is closer to the$c \bar{c}$(6S) state. The status of \$$\backslash$psi \$ (4415) is still not clear as it does not fit to be pure or admixture state

Shaping Code

To allow society to intervene and proactively shape code (i.e., the software and hardware of information technologies), we analyze a number of mechanisms and schemes concerning how society can shape the development of code. These recommendations include regulatory and fiscal actions by the government, as well as actions that public interest organizations can take to shape code. These recommendations also include a number of specific policy prescriptions, such as prohibitions on code, using standards or market-based incentives, modifying liability, requiring disclosure, governmental funding for the development of code, government\u27s use of its procurement power to favor open source code, export prohibitions on encryption code, developing an insurance regime for cybersecurity, and fashioning technology transfer policy for code. For each measure, we identify and discuss regulatory and technological issues that affect its effectiveness. The result is a more informed approach in weighing the alterative approaches to shaping code. We do not attempt to determine the comparative efficiency of different approaches to shaping code, because, in part, that analysis is a factually laden inquiry depending on the specific characteristics and issues related to the particular type of code in question. These recommendations will allow policymakers to better anticipate and guide the development of code that contributes to our society and reflects its values and preferences