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.

Synthesis of an optimal digital filter of a compensation radiometer for radiometric correlation-extreme navigation systems of unmanned aerial vehicles

Abstract: The expediency of using a compensation radiometer (CR) with periodic absolute calibration as a sensor for preprocessing the information of correlation-extreme navigation systems (CENS) of unmanned aerial vehicles (UAV) was shown. This is determined by the possibility of obtaining and using the estimates of gain fluctuations obtained in previous frames which will provide an increase in the radiometer sensitivity. In addition, due to the accumulation of information, an increase in accuracy of measurement of the elements of the current image formed by the CENS will be provided. The algorithm of processing the obtained calibration estimates during linear processing corresponds to a certain digital filter (DF). By defining a set of the DF weight coefficients, it is possible to improve the CR fluctuation sensitivity by reducing the gain fluctuations. Up to 1.8-time gain in sensitivity can be reached for typical frequency and time parameters of the compensation radiometer of UAV CENS. The problem of synthesis of a digital filter was set. A solution to the problem of synthesizing an optimal digital filter was proposed. Its use in a CR will improve the fluctuation sensitivity. In its turn, this will make it possible to improve the quality of a current image generated by the system when siting by means of sighting surfaces with low-contrast objects taking into account fluctuations in radio-brightness temperature. It was found that the gain in sensitivity when using the optimal digital filter increases with an increase in the operating period of the radiometer and an increase in the digital filter order. Improvement of fluctuation sensitivity of the CENS data preprocessing system is important for UAV location in low-contrast areas

The Expediency of Identifying Strategic Alternatives to the Development of the State's Economic Security System Through SWOT Analysis

Abstract: The outcomes of the conducted research presented in the article will be valuable for managers of all levels involved in strategic planning and management of the modern economy of the state. The article addresses the urgent issue of identifying certain strategic alternatives in the development of the state's economic security system. The analysis of existing threats to the economic security of the state is conducted; the approaches to the definition of economic security are analyzed. The study emphasizes the complex political, social and economic situation in Ukraine due to the difficult situation in eastern Ukraine and the temporary occupation of the Republic of Crimea. It draws attention to the place of Ukraine in the ranking of international organizations and provides information on the main forecast macroeconomic indicators of economic and social development of Ukraine for 2020-2022. It is determined that the economic security of the state is based on self-sufficiency, stability and development of all constituent elements of the economy, and their list is given. The article emphasizes the priority development of the economic security system in the conditions of continuous improvement of the scientific and technical market, constant modernization of production, development of educational institutions, creation of a favorable climate for investment, significant state support of innovative activity. The possibility of using SWOT analysis as a tool for determining strategic alternatives has been investigated and confirmed. The article analyzes information and gives a detailed description of the elements (components) of SWOT analysis. The algorithm of estimation with use of SWOT analysis is graphically presented. The method of carrying out SWOT analysis with corresponding detail of each stage is presented. The study identified and analyzed the advantages and disadvantages of using SWOT analysis in comparison with other methods.

Electrochemical studies on cellulose acetate-LiBOB polymer gel electrolytes

Abstract: Liquid electrolytes were prepared by dissolving different amounts of lithium bis(oxalato) borate (LiBOB) in γ-butyrolactone (GBL) solvents. Upon addition of 0.8 M LiBOB in GBL solvent, this liquid electrolyte showed room temperature ionic conductivity of 4.79 mS cm −1 . In order to prepare polymer gel electrolytes (PGE), 1 to 6 wt.% cellulose acetate (CA) was added into this optimum liquid electrolyte composition. The highest room temperature conductivity obtained for the PGE system was 5.36 mS cm −1 for sample containing 2 wt.% CA. Temperature dependent conductivity data revealed the CA-LiBOB polymer gel electrolyte obeys an Arrhenius rule implying that this PGE could operate at intermediate and high temperature conditions. Moreover, linear sweep voltammetry (LSV) and cyclic voltammetry (CV) measurements confirmed this PGE system also exhibits excellent electrochemical stability. Thus, the CA-LiBOB -based PGE could be a promising candidate as an electrolyte particularly in lithium batteries application.

Systematically study on the magnetism and critical behaviour of layered NdMn1.4Cu0.6Si2

Abstract: The strong dependence of the field-induced on the body-centered tetragonal ThCr2Si2-type and the critical behaviour of magnetic phase transition in NdMn2-xCuxSi2 based compounds guide us to study the substitution Mn (atomic radius = 1.35 A) by Cu (atomic radius = 1.28 A) in layered NdMn1.4Cu0.6Si2 compound. Room temperature x-ray diffraction study indicates clearly that most of the reflections can be identified with ThCr2Si2-type structure with space group I4/mmm. It found lattice parameters a slightly increases and lattice parameter c decrease compare to NdMn2Si2 as indicated the decreasing of volume structure. The Neel temperature TN is found at 340 K while Curie temperature TC found at 75 K respectively. The increasing concentration of Cu in replacement of Mn changes the magnetic phase transition from first order type for NdMn2Si2 to second order type for layered NdMn1.4Cu0.6Si2 compound as been determined by particular the S-shaped nature of the Arrott plot near TC. Our results indicate that the magnetic-field-induced magnetic phase transition plays a critical role on producing large magnetocaloric effect in these systems especially on second order type as the key for further investigation. The critical behaviour analysis in the vicinity of TC demonstrates that the magnetism of the layered NdMn1.4Cu0.6Si2 compound is governed by long range interactions.