Vojnotehnicki glasnik / Military Technical Courier

30-46

Authors: Ionel A. Staretu

In general, anthropomorphic grippers for robots are similar to the human hand and they can have two, three, four or more fingers, with two or three phalanxes. Anthropomorphic grippers for robots compared to other mechanical grippers have more advantages such as: a higher degree of dexterity, a larger area of utility (more types of objects can be grasped) and a micro-movement of the grasped objects can be performed. This paper describes two groups of anthropomorphic grippers for robots: traditional mechanical anthropomorphic grippers and modular mechanical anthropomorphic grippers designed under the author’s coordination. For the first group, more versions with two, three, four and five fingers are shown and for the second group, there are more modular solutions shown. The stages of synthesis, analysis, design, and functional simulation are briefly shown as well.

64-86

Authors: Branka D. Mikavica, Aleksandra M. Kostić-Ljubisavljević, Vesna M. Radonjić-Đogatović

Fractional calculus is a field of mathematical analysis concerned with research and application of derivatives and integrals of an arbitrary order. Many famous mathematicians studied the theory of fractional calculus such as Euler, Riemann, Liouville, Abel, Fourier and others. There are many proposed definitions for calculating derivatives and integrals of non-integer order. In this paper, several proposed definitions along with basic statements of fractional calculus are presented with an emphasis on a possibility of fractional calculus application in telecommunication traffic modelling. The fact is that fractional calculus is widely used in various scientific disciplines in recent decades. Models based on fractional calculus have proved to be very useful in physics, mechanics, electrical engineering, biochemistry, medicine, economy, and probability theory. This paper analyses a possibility of application of fractional calculus for modelling telecommunication traffic. Many research studies have shown that traffic characteristics at a local and global level, such as self-similarity and long range dependence, can efficiently be described by fractional calculus instead of using conventional stochastic processes. Some proposed models based on fractional calculus that describe phenomena present in modern telecommunication networks are presented in this paper. Introduction Measurements and statistic analyses of telecommunication traffic have discovered that traffic in packet switched networks shows significant irregularities – burstiness, both in terms of traffic intensity variability and shape of autocorrelation function. It is noticed that traffic has fractional characteristics – self-similarity and long range dependence. As a result, a large bandwidth is required, and very often, this is one of the causes of network inefficiency. In comparison with conventional models based on Poisson distribution widely used in circuit switched networks, in models based on self-similarity property there are problems that are difficult to predict, measure and control in telecommunication traffic. Thus, measurement, analysis and modelling of self-similar network traffic are a sort of challenge. Different research studies have shown that traffic in modern telecommunication networks can efficiently be described with statistical models based on fractional calculus. Basic statements of fractional calculus Although the term „fractional calculus”, is actually a misnomer, and a term „integration and differentiation of an arbitrary order” is more suitable, „fractional calculus” has been a common term since l'Hopital’s era. Fourier also studied derivatives and integrals of an arbitrary order. Abel applied fractional calculus for an integral equation which appears in a tautochrone problem formulation (find a shape of a curve for which the time taken by an object sliding without friction in uniform gravity to its lowest point is independent of its starting point). The first serious attempt to obtain a logical definition of a fractional derivative belongs to Liouville. Let f be a locally integrable on (a, ∞). Usually, an n-fold iterated integration is marked as , and refers to as Riemann-Liouville fractional integral of order α of f. Definitions of integrals and derivatives of an arbitrary order can be consolidated into a differintegral. The process of obtaining a differintegral is referred to as fractional integro-differentiation. Some proposed models of fractional calculus application for telecommunication traffic modelling Recent research of telecommunication traffic has shown that it can efficiently be described by derivatives of an arbitrary order instead of conventional stochastic processes. A new interpretation of fractional calculus creates new fields of application of these mathematical tools in order to achieve understanding of local and global characteristics of network traffic. A fractional dimension and long range dependence can be seen in private, LAN and WAN networks. Temporal-spatial model for packet transmission in TCP/IP networks Defining Quality of Service parameters for Internet services requires appropriate virtual connections, depending on traffic flows. Generally, such a connection consists of several transit nodes and links. In modern TCP/IP networks, delay in a given virtual connection can be considered as a constant value. A buffering delay variation causes a propagation delay. The transmission process can be described by equations that can be solved by fractional calculus. Fractal analysis modelling of telecommunication traffic-potentials and limitations The fractal properties of telecommunication traffic in packet switched networks indicate the existence of periods of low or high activity concentrations in long time intervals. As a result, the correlation structure of traffic streams is in contradiction with common models. Therefore, the empirically confirmed fractal properties of aggregate traffic cannot be described by Poisson models. All streams are statistically multiplexed with local irregularities in nodes. Thus, each packet is stochastically delayed and non-trivial processes occur. In order to achieve a complete description of these processes, it is necessary to involve the properties existing in short and long intervals in such an analysis. The fractional analysis of packet flows in different time intervals ensures a qualitative and quantitative description of the telecommunication traffic fractional nature. Conclusion Fractional calculus has many applications. This paper is primarily concerned with fractional calculus application for telecommunication traffic modelling. It was shown that an indefinite packet delay in the transit node in packet switching networks adequately models the dropping of the packet in the node. The dynamics of packet transmission in virtual connections in TCP/IP networks can be described by the equations in fractional derivatives and it corresponds to processes with long-range-dependence. Also, fractional calculus can be a very useful tool in the research of local and global phenomena in telecommunication networks.

108-130

Authors: Marko D. Andrejić, Ivana M. Andrejić, Slaviša N. Arsić, Srđan D. Ljubojević

Robust and dynamic organizational changes that have been carried out in defense in recent years affected the field of higher education and scientific research related to defense . A creation of a new, integrated research and education system, harmonized with the national system, is underway. Such a system will be resilient and partly self-sustainingt and useful not only for the defense area, but also for the wider community. Introduction Higher education is a very important part of the strategy of power and the influence of a real defense system. Creativity as a basic resource produces innovations which can enhance and improve the defense system. Organizational changes in the country over the last decade did not miss its defence system, an important state function and the field of objective social reality. The most important change in the defense system has resulted in the formation of the UD. Approach to improving teaching and scientific work at the Military academy and the University of Defence Education should not be seen as a cost but as an investment, seriously prepared in the adequate organizational environment (Andrejić et al, 2011, pp.5-26). As a result , the improvement of the quality of education and research at the UD should be aligned with the long-term development concept of the defense system and the society as a whole, taking into account the technology of the process of education and training since fast, cheap and, at the same time, high- quality solutions in education are not known . It is possible to achieve a necessary flexibility in response to significant technological and organizational challenges by improving and developing new programs to meet the needs of practice . Institutional framework for the advancement of teaching and scientific work in the Military Academy and the University of Defence Before applying organizational measures and procedures aimed at improving the quality of education and research at the Military academy, it is necessary to know the relevant factors and preconditions of organizational changes . From the production-process point of view, it is necessary to reduce the range of products provided by theUD and to gradually specialize in certain products, in order to ensure internal and external competitiveness. In this regard, it is necessary to create conditions so that lecturers of methodological and theoretical academic general education courses at the UD are experts from relevant civilian universities while the UD and the Military Academy in particular should develop teaching and research human resources for scientific-professional and professional-applied science courses. The main activity and the purpose of the Military Academy should be clear to an objective and independent observer.from outside the Academy. Within the Military Academy, all functions and business processes should aim at quality higher education and research in the field of defense. In accordance with the requirements of time, a conceptual orientation and the nature of the University itself, the academic spirit and freedom must take precedence over professional aspects of education (performance of training centers and colleges of professional studies). At the same time, higher operating efficiency and effectiveness are necessary to reach strict criteria and requirements of the modern academic environment . Management of changes to improve the teaching and scientific work at the Military Academy and the University of Defence Change management involves coping with challenges that can be identified as: lack of creativity and value or cultural barriers; group solidarity, group thinking; conformity in relation to the previously accepted norms; structural divisions; distribution of authority; technology; philosophy of management; management style, etc. The man is the dominant factor of changes and good understanding of the nature of human behavior is a necessity and the measure of all actions taken. For detecting, understanding and overcoming the passivity of change (maintaining the "status quo "), it is necessary to choose adequate management staff. Conclusion The management and organization of the system can be improved by encouraging changes at the micro, meso and macro levels and by professional approach in the selection, training and development of managers. The University of Defence needs to be further developed and strengthened through the improvement of quality in the performance of primary activities, quality management and planning and the introduction of a labor - stimulating system. The comparative advantages on which it is possible to base the changes are: knowledge, experience and "know how" . The attitude towards one’s own future is reflected in the attitude towards creativity and knowledge as the most valuable resources, which can, to some extent, compensate for the lack of material resources - therefore, they need special attention.

146-160

Authors: Adnan M. Mulaosmanović

This paper is about the PROFINET communication used in industry for the purposes of communication between different elements within systems of monitoring and control of production processes. The PROFINET protocol is based on industrial Ethernet and allows the use of TCP / IP standards, which allows big business benefits during the life cycle of a manufacturing plant. Also, PROFINET is based on all the experiences with PROFIBUS, and goes a step further in its flexibility, improving performances. PROFINET enables the integration of various control equipment from the factory level to the control level. The concept of PROFINET satisfies all the requirements of industrial automation, and can be used for process automation that requires quick response time, i.e. the time below 100ms. For the purposes of other applications such as synchronized motion control,it enables a response time of less than 1 ms, and for safety applications it is possible to use PROFIsafe which is integrated into PROFINET. Introduction Industrial systems themselves are very complex so it is inevitable to divide them into parts that complement each other and communicate via protocols which will be discussed in this paper. The basic requirement of an industrial automation system is work in real time as well as reliability, unlike a business network where the primary conditions are high throughput and low operating costs. Fieldbus Fieldbus is a name that describes a modern industrial digital communication system designed to replace the existing current and voltage analog signals. The design and implementation of projects with a lot of cabling is quite complex as well as their maintenance. A different approach is therefore needed so the transition from analogue to digital methods of data transfer has started, since digital methods also provide greater accuracy than traditional analog signals. PROFINET standard PROFINET satisfies all the requirements placed before it in automation technology, no matter whether it is manufacturing plant automation, process automation or machinery automation. It has already been used in the auto industry as a standard technology for a long time. Also, PROFINET is in use in other industries such as machine industry, food industry, packaging and logistics, and every day more and more is in use in other industries such as shipbuilding and railways. PROFINET versions In PROFINET, there are two function classes independent from each other, PROFINET IO and PROFINET CBA. The distributed field devices are connected through the PROFINET IO. Also, it uses three diferent communication channels to exchange data with the control systems and other devices. For Non real time (NRT) purposes, the standard TCP/IP chanel is used for parameterization, configuration and acyclic read/write operations. The real time (RT) chanel is used for standard cyclic data transfer and alarms. Isochronous real time (IRT) is a high speed chanel used for motion control applications. The PROFINET CBA concept is designed for the distributed industrial automation applications, and it is suitable for component-based machine-to-machine communication via TCP/IP and for real time communication required for modular plant design. Conformance classes The range of functions of PROFINET IO is divided into well-organized conformance classes (CC). These conformance classes provide a practical summary of various minimum properties. There are three conformance classes that build upon one another and are oriented to typical applications.These classes are CC-A, CC-B and CC-C. Cabling Specificic working conditions in which devices operate in industrial production require components that are a lot more resilient than devices operating in office conditions. PROFINET cabling is based on the link End-to-End, which is specified in IEC 61784-5-3. PROFINET defines a one-to-one straight connection. Copper cables and optical fibers are available for connection of network nodes. All cables must meet the requirements of a planned automation project. Network nodes parameters For proper work of network nodes, appropriate parameters for individual network nodes have to be assigned. These parameters include a device name and an IP address. New equipment does not have a device name, only a MAC address, which is globally unique and cannot usually be modified. Network components Only units with switch functionality are allowed as signal distributors for PROFINET. A switch is a layer 2 device which complieswith ISO/IEC 15802-3:1988 standard, and it receives data packets at its ports and forwards them selectively. It can also send and receive different data simultaneously at all ports. Conclusion As it can be seen, PROFINET represents a number of improvements in industrial communications. At the level of major production systems with a growing number of PLCs and PC computers that communicate with each other and with the rest of the IT system by exchanging large amounts of data, PROFINET shows to be a much better solution than PROFIBUS. PROFINET is based on industrial Ethernet.

179-194

Authors: Miloš Z. Petrović, Snežana M. Đorić-Veljković, Jugoslav P. Karamarković

The looks of any environment, the identity of which is expressed through its form, structure and color, is one of the most significant characteristics of any area. The first structures that catch the observer's eye are buildings and urban structures. People have always attached importance to the choice of building materials and interior design. Materials used have been specific for certain regions. In the era of modern technology and the expansion of new technical advances, the man and his environment require materials which are going to enrich living space, while constructions and shaped volumes will be made richer and more content aware. Materials should fulfill criteria which allow comfort, provide efficient energy consumption, healthy living conditions and preserve the environment. Buildings significantly change our environment. Most of such man-made objects do not comply with the needs of environmental protection because they are energetically inefficient, too cold or too hot and expensive to maintain. They are mostly built of materials which have a negative effect on health and environment. About 40% of stone and small and big aggregate are used for their production, as well as 25% of timber. Such objects waste 40% of energy and 16% of water worldwide. The use of eco-friendly materials results in objects with a minimal influence on the environment and at the same time such materials are more economical and healthier for living. Environmental protection and construction means the maximum utilization of natural site conditions, usage of healthy materials, efficient consumption of water and energy for building and use of water. In the process of European integration of Serbia, there is a harmonization of the national regulations regarding the environmental protection with the EU regulations. This process includes the transfer of a significant part of jurisdiction in this field to the local government level, including jobs which refer to global environmental problems. The influence of ecology is an important global issue. There is a huge pressure from many sides to minimize influence - requests often come from governments, trade associations and other social and financial stakeholders. The implementation of "ecologically eligible products", i.e. materials used in construction and consistent with the protection of the environment, is one of the first steps towards the realization of the concept of sustainable development and environmental protection. These materials are flexible, reliable, durable, and suitable for repeated use. Environmental compatibility of materials is of great importance in the context of the production of consumable resources. The focus of the production is to create wasteless methodologies that optimize production and maximize environmental performances. The basic features are: - reduced amount of materials used, - use of recycled materials, - use of materials from the immediate environment, - increased energy efficiency, - increased longevity of the product, - use of materials with less impact on the environment, - reduced amount of waste, - property of re-recycling (recyclability), - capable of measuring carbon footprint, and - applied principles of sustainable development. The reduction of an environmental impact is also highlighted. This applies to the entire ecological life cycle, from raw material extraction to product disposal (clean production). Currently, the aim is to optimize the entire socio-economic system of the product, as well as to meet the criteria for sustainable development and environmental protection. Brick is the most widely used building material in the region. It is easily available, accepted and does not require additional education of contractors. It is very durable and resistant to moldering and insects. Because of its density, it warms more slowly in summer and in winter it cools more slowly, which helps to maintain the temperature inside the object. Modern brick manufacturers have improved their production in order to pollute the environment less . Wood is the "greenest" material. If forests are kept regularly, trees will grow without violating a natural balance. Wooden structures can last for centuries without being damaged by the elements. That is, if they are properly protected from moisture, insects and unforeseen damage. It is biodegradable and it does not make any damage and negative effect on the environment. A relatively small amount of energy is needed so that wood can be processed and prepared for building, but wood requires regular constant maintenance and coating chemicals for protection. These coatings are expensive and anything but ecological and they have negative influence on the environment. Simprolit blocks have excellent sanitary - epidemiological characteristics. In objects built of Simprolit blocks, environmental requirements are completely fulfilled. Simprolit block walls are declared as "dry" (no more than 4% of moisture). In case of soaking, during great damage , such structures dry quickly without any loss of their physical characteristics. During floods, Simprolit block walls do not absorb moisture by means or capillary climbing like brick, siporex, foam concrete and other materials (in case of floods, walls of these materials absorb water along the entire height, and it takes time to dry , sometimes more than a year). In the class of lightweight concrete, Simprolit polystyrene is one of the lightest. Building facade and inner walls using Simprolit blocks significantly reduces the load on the structural elements of objects, reduces their dimensions and also reduces needed armature and weight, which directly impacts the construction f costs. Low emissivity glass is an important EKO material. Low emission glass or Low-E glass is a microscopic thin layer of a metal or metal oxide, which is applied on the glass by vapor deposition of a metal on a molecular level. Glass coated with a metal film only allows short wavelength radiation (visible part of the spectrum), while it reflects the long wavelength radiation (infrared rays) from the warm side of the glass onto the cold side. LOW-E blocks almost 98% of harmful sun rays, so in the cold period big glazed house rooms can become collectors of solar energy, so they can contribute to save precious heat. Glass which protects fromsun is made as a single glass surface or insulating glass. Its purpose is to keep back the solar energy which falls onto a glass surface. This glass does not have protection from glaring. A protective coating is applied on the inner side of the exterior glass. Self cleaning glass is hydrophilic and hydrophobic glass based on a “lotus effect”. A hydrophobic glass surface repells water and a hydrophilic one does the opposite. The development of bionics saw the usage of various effects occurring in many plants including a lotus leaf, i.e. a lotus effect. The leaves of the lotus cannot get wet, and after the rain they are dry and clean because water which slides down the leaves takes the dirt and dust, so the leaf stays clean. The droplets of water can pick up particles of dirt because the microstructure (namely, nanostructure) of a lotus leaf surface is such that minimises the adhesion of water droplets to the surface. Active Ceramic tiles are responsive to contaminants in the air, and turn them into non-toxic mineral salts. The tiles can be used both indoors as well as outdoors. This new invention is designed by dr. Romana Minozzija from Italy and his team. A group of scientists intended to "build a new tile that is not only aesthetically pleasing, but which also has a unique feature, play an active role in improving the quality of human life." Active ceramic plates are coated with a layer of titanium dioxide. When it is exposed to the light or when in humid environment, titanium dioxide activates and starts a chemical reaction. The process is called photocatalisis. Green and smart concrete are also materials used for building structures in civil engineering. Green concrete refers to various activities of efficient consumption of cement, whose production releases large amounts of carbon dioxide. In recent decades,modern civil engineering and environmental protection face a problem correlated with the structure and the protection of the environment, because the impact of some building materials can be harmful to human health and the environment as well. Materials in buildings, machinery and equipment can also contain very dangerous and harmful materials. Some of more affordable solutions are given in this paper together with the presentations of some ecological materials and the postulates of environmental protection.

204-209

Authors: Branislav S. Bulatović

Automatic rifle H & K G36c 5.56 mm

227-237

Authors: Mladen R. Tišma

The first flight of the military version of the helicopter EC645T2; Raytheon performing flight tests of a new generation of jammers; The first flight of the Russian Mi-171A2; Maiden flight of the third prototype of the Indian Light Combat Helicopter; Tests of British weapons for F-35B; Progress and delays in the development of India's light fighter Tejas; Russian naval combat helicopter Ka-52K performed the first flight; IAF’s Mi-26 helicopter accomplished the first landing at high altitude; Iran unveiled a new version of the domestic light fighter; Saab offered Sea Gripen to Brasil; Airbus and KAI develop a light helicopter gunship in South Korea.

245-259

Authors: Nebojša N. Gaćeša

Call for papers for issue no. 2-2015