Vojnotehnicki glasnik / Military Technical Courier / Военно-технический вестник

This paper presents the results of a comparative analysis of Serbian phonemes. The characteristics of vowels are quasi-periodicity and clearly visible formats. Non-vowels are short-term quasi-periodical signals having a low power excitation signal. For the purpose of this work, speech production systems were modelled with linear AR mod els and the corresponding non-linear models, based feed-forward neural networks with one hidden-layer. Sum squared error minimization as well as the back-propagation algorithm were used to train models. The selection of the optimal model was based on two stopping criteria: the normalized mean squares test error and the final prediction error. The Levenberg-Marquart method was used for the Hessian matrix calculation. The Optimal Brain Surgeon method was used for pruning. The generalization properties, based on the time-domain and signal spectra of outputs at hidden-layer neurons, are presented.

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Разработана математическая модель газодинамического обтекания плоской пластины при ее движении с положительным и отрицательным углом атаки. Показано, что при малых скоро стях движения пластины подъемная сила и лобовое сопроти вление определяются газодинамикой течения воздуха в тыль ной области, а при скоростях движения близких к скорости зву ка решающую роль выполняет ударное взаимодействие пласти ны с молекулами окружающей среды в передней области. Срыв ное течение за пластиной при малых скоростях движения не во зникает. Определены условия, когда лобовое сопротивление и подъемная сила пластины изменяет знак.

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The article draws attention to the development of science and technology in 19th and 20th century, biology and chemistry in particular, and its relation with the green revolution of the middle of 20 th century and the gene revolution of the end of 20 th century. These two revolutions have resulted in significant changes in food production and integrated agriculture into high technology-based economy.

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Shape memory alloys -SMAs are specific materials which has the ability to change their shape and return to some memorized state, which is caused by the changes in their temperature. Because of their specificity and unusual characteristics, the area of usage of SMAs is very large and heterogeneous. SMAs are mostly biocompatible, which enables their usage in medicine. Some basic characteristics of the shape memory alloys, different types of their transformations, as well as some possibilities of their usage in medicine will be presented in this paper.

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The paper presents the results of alloying titanium by oxygen in the process of chamber electroslag remelting. As an oxygen-containing ligature, we used the electrodes-satellite from the reaction mass residues mixture from the retort lid for magnesium thermal reduction of a titanium sponge, a specially prepared gaseous argon oxygen mixture containing 30% oxygen applied directly to the melting space, micro-size (10-15 mm) powder particles of titanium oxide and titanium oxide nanopowder with a particle size of 21 ± 5 nm. The structure and the properties of titanium alloyed by oxygen from the oxygen-containing ligature, gas phase and titanium oxide powder during chamber electroslag remelting of the titanium sponge are investigated. It was found that at the oxygen content of 0.053%mas. to 0.22%mas. in the metal formed a homogeneous single-phase structure typical for commercial titanium formed by polyhedral grains of the α-phase. The increase of the oxygen concentration in titanium for more than 0.22%mas. leads to the formation of the microstructurewith a typical -phase. αneedle structure, which allows it to be classified as the

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The work presents research of the materials necessary for the maintenance of protective ballistic vests. In this paper is proposed a new construction design with modern materials for ballistic inserts producing. This paper also presents the results of laboratory tests of ballistic cartridges with new materials. Based on the test results, it can be concluded, the proposed technical solution for making ballistic inserts adequately meets current standards.

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Logistics is a set of activities for planning and implementing the relocation of materials. Since sources of raw materials, factories and outlets are not usually in the same location it is therefore necessary to conduct a series of logistics activities for supplying products or services to end users. Logistics manages the flow of data from suppliers, movement of materials through various operations within the organization as well as the flow of materials to final customers. Integrating these logistics activities is performed through supply chains which provide opportunities for cost saving and offering better services to customers. The supply chains in the Macedonian Army are an important factor in the planning and implementation of logistics support.

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The effects of prestressing forces on a reinforced concrete frame are shown in the paper. The structure is a statically indeterminate frame with two fixed supports. The load is due to tendon prestressing with Nk = 600 kN and due to self-weight of columns and beam. The columns height is 6.00 m and the beam span is 20.00 m. Effects of prestressing can be replaced by an external equivalent load. Calculations are performed by the force method, by the direct stiffness method and using the “Tower” software. The rotational restraints are released at fixed supports and the restraint moments are calculated by the force method. The direct stiffness method uses the members’ stiffness relations for computing member forces and displacements in structures. The unknown nodal rotations and translations are obtained by solving a system of equations. The considered tendon profile is without eccentricity above the columns. “Tower 7” is software for static and dynamic structural analysis and for design of concrete elements. It enables overall structural analysis of plane and three-dimensional structures. Automated, integrated tools allow fast and reliable design or the verification of the results obtained by standard methods. Version 7 is a professional tool with high performance. Three different calculation methods have given close results, with minor differences.

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It is difficult to achieve rational engagement, directing and developing, motivating, rewarding, and improving organizational efficiency, without the evaluation of the quality of job performance of employees. In management literature, this technique is known as

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Besides geographic maps, atlases represent the most important cartographic models of environment. Nowadays, contemporary geographic information systems (GIS)are increasingly used ' in planning, designing and predicting the conditions and processes of complex dynamic spatial systems. Collecting data and information for a specific geographical map and GIS represents its basis.

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The process of professionalisation of the Serbian Army has caused qualitative and quantitative changes in the personnel structure and has led to the reduction in the numerical strength of its members. The restaurant at the Military Academy has faced infrastructural and organisational ballasts in its capacity for food preparation and distribution thus making the Military Academy food system uneconomic. The capacities of the restaurant are designed to allow for the preparation and distribution of 40% more meals than the actual needs, which, in the economic context, places unnecessary financial burden on the limited amount of funds allocated for this purpose. In terms of economic principles, it is possible to reduce or completely eliminate the negative effects through employing redundant workforce or finding alternative ways to organise the food system at the Military academy in a more rational way. The article represents a

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The Serbian Army is the only institution of the social system in the Republic of Serbia which posesses amphibious vehicles and uses them for their designated purpose. The goal of this paper is to draw conclusions regarding the influence of amphibious vehicles on the three parts of the environment many scientists find the most important: land, air and water. The paper processes the influence of amphibious military vehicles on the basic parts of environment, as well as the measures for the improvement of safety and environmental management systems regarding the change in the usage and reconstruction of the vehicles. This paper is based on the authors’ own experience in work with amphibious vehicles combined with the basic theoretical postulates of the safety and environmental management systems. It also shows how many negative consequences on the environment can be caused by just one type of the military vehicles. It is very important to emphasize that this paper does not include all negative influences of amphibious vehicles on the environment, since it is based on the negative influence of amphibious vehicles on the basic indicators of environment only.

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An oven for baking bread in field conditions is assigned to units that are by their nature relatively stationary and whose size does not require a movable bakery. It is intended for baking bread in our units located in international missions with supply difficulties, since our units have a habit of consuming bread instead of biscuits. The oven is of a prefabricated type, adapted for use in all types of terrains, simple design which makes it possible to be, dismantled and easily transported.

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Единообразие в маскировочно-защитных конструкциях резко увеличивают выживаемость танков на марше -основной ударной силы, т.к. при его применении будет сложно отличить танк от ав томобиля или пустого прицепа. Применение, при этом, тента из многослойной ткани высокой прочности обеспечивает преждевре менный подрыв противотанковых кумулятивных снарядов. С уче том того, что большая часть этих снарядов рассчитана на актив ную броню, первый взрыв будет не на активной броне, а на ткани тента, а второй ─ основной взрыв произойдет уже на активной броне, и кумулятивная струя будет разрушена взрывом активной брони. Стоимость конструкции значительно ниже надувных моде лей техники, а по эффективности значительно их превосходит. В статье приводится анализ средств борьбы с бронете хникой и методы наведения на цель «умных» боеприпасов, а также анализ методов борьбы со средствами нападения. Описан способ борьбы с «умными» боеприпасами и работа за щитно-маскировочного средства. Приведено описание патента.

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