National Defence University, Pakistan

About: National Defence University, Pakistan is a education organization based out in Islamabad, Pakistan. It is known for research contribution in the topics: Context (language use) & Decision support system. The organization has 802 authors who have published 816 publications receiving 3701 citations. The organization is also known as: National Defence University of Pakistan & National Defence University Islamabad.

High-temperature susceptibility series for square-lattice ising model with first and second neighbour interactions

Abstract: We have calculated the high-temperature series expansion of the zero-field susceptibility of the square-lattice Ising model with first and second neighbour interactions to the 20th order by computer. Our results extend the previous calculation by Hsiao and Lin to two more orders. We use the Pade approximants to estimate the critical exponent γ and the critical temperature. Our result 1.747 < γ < 1.753 supports the universality conjecture that all two-dimensional Ising models have the same critical exponent γ = 1.75.

Complex Substantiation of Reliability and Maintainability Requirements for Mobility Means of Surface-to-Air Missile Systems

Abstract: General principles regarding the complex substantiation of reliability and maintainability requirements are considered for the mobility means of surface ‐ to ‐ air missile systems (SAMs), which take into account the impact of the hierarchical-branched structure of SAM system, the values ​​of the reliability and maintainability of the mobility means on their effectiveness under the real conditions. The coefficient of effectiveness sustainment is used as an indicator of the effectiveness of the mobility means of SAMs, which is the ratio of the characteristic of the output effect, taking into account the reliability and maintainability of the mobility means to its value in the case when the mobility means do not fail. The coefficient, used here, is the function of mean distance between failures (MDBF) and the average recovery rate of the combat and technical mobility means of SAM system.

SIMSCRIPT: A Programming Language for Military Simulation

Abstract: SIMSCRIPT is high-level simulation language with a long history and world-wide acceptance, especially in the field of military simulation The paper first introduces the SIMSCRIPT world-view and its simulation mechanism, which lay the basis for its success, and next points out the language's prominent advantages from the viewpoint of a military modeler, and also lists its weaknesses which are yet to be improved, and then proposes suggestions to better utilize the capability of the simulation language, and last discusses the development trend of SIMSCRIPT

Characterizations on bending effect on customized splitters using various radii of elliptical-shaped blocks

Abstract: Macro-bending effect unto polymer optical fiber (POF) based splitters study is done to analyse the performance and characterizations using several bending radii of geometrical blocks that hold a customized prepared polymer fiber splitter. A pair of etched fibers with similar core diameters are attached to the ellipse-shaped blocks built using matching refractive index material where the blocks were built with various bending radii. The tapered fibers were lapped closely with some forces exerted upon them in order to stimulate the splitting of modes between the two fibers. This study is done by experimental set-up where each of the splitter ports is connected with optical power meter to measure the power output while pressure is exerted. Characterization is executed in order to investigate and analyse which bending radius gives the most optimize splitting ratio with considerable low loss for the particular splitter prepared. As for normal force of 0.3 lbF, the optimum splitting ratio with low loss is specified having bending radius, Rc, of 13 mm whilst for external force of 3.0 lbF, bending radius is found to be 19 mm. Small bending radius stimulates the radiation of rays into the second fiber while larger Rc gives longer coupling length that optimize the splitting ratios. Efficiencies between simulated values and experimental values are also analysed.