Volumen 26 (2020): Edición 3 (June 2020)

The paper investigates the capabilities for increased productivity, reduced lead times, and higher product quality with the concerted use of CAD/CAM/CAE and software platforms for workgroups. For the purposes of this report, the design of the reusable training-practice mortar round for short distance firing is used as an example.

The article explores contemporary computer tools for calculating stress-strain of mechanisms and elements for heavy weapons and machine guns. The article is intended to aid the knowledge and skills requirements in the future work of engineers and constructors in machine engineering and weapon systems.

The paper analyzes, starting from the Integrated Management System, the role of automation, the role of the officer and the role of the Energy Management System on board the ship. The implementation of an EnMS establishes the structure and discipline of identifying energy flows, implementing management actions and, finally, applying technical solutions, which significantly reduce energy costs, reduce non-productive time in production, and reduce emissions. of Greenhouse Gases in the environment. The steps to be highlighted in the realization of energy management are analyzed.

The paper analyses the role of control and monitoring of electro-energetic equipment in order to reduce operational costs, increase profits and reduce carbon emissions. The role of SCADA and EcoStruxure Power systems is presented and analysed taking into account the energy consumption and its savings. The paper presents practical and modern solutions to reduce energy consumption by up to 53%, mass by up to 47% and increase the life of the equipment by adjusting the electrical parameters. The Integrated Navigation System has allowed an automatic control and an efficient management. For ships, the implementation of an energy efficiency design index and new technologies was required for the GREEN SHIP project.

The blending interpolation has many practical applications. Remind that blending interpolation is to interpolate a function at an infinite set of points: segments, curves, surfaces, etc. Thus, if one gives the contour of an object by such elements (segments, curves, surfaces) using a blending interpolation, we can generate a surface that contains the given contour. Hence, we can construct a surface (a blending function interpolant) which matches a given function and certain on its derivatives on the boundary of a plane domain (rectangle, triangle, etc. The aim of this paper is to construct some surfaces which satisfy some given condition on the boundary of a domain that can be decomposed in triangles with one curved side. We construct some new surfaces using some Lagrange, Hermite, Birkhoff and Nielson type operators.

Even with the present-day development of mobile communications in UHF and SHF spectral bands and recent trends to move to mmWave, HF radio communications still offer advantages that make them exclusive in some application areas. Cognitive Radio principles can be applied to HF communications, to make use of the spectrum more efficiently. A significant improvement of Cognitive Radio technique can be achieved by spectrum occupancy prediction, which enables proactive efficient spectrum utilization. Hidden Markov Models (HMM) can be a useful tool for statistical spectrum occupancy prediction. In some of our previous works, we investigated a simple HMM in time domain, as well as a bidimensional model, that take into account both the time domain and the frequency domain. In this paper, we propose to extend the coverage of the model, by considering in addition to time and frequency the geographical position of the two points involved in the radio connection. The work is motivated by the fact that the two points of the radio link in HF can be far apart, and the channel availability at the two points could be different. Therefore, finding and exploiting correlations between the spectrum occupancy at the two points might improve the connectivity. The proposed model is validated using real spectrum occupancy data collected simultaneously at two locations situated in two cities, namely Timișoara and Sibiu, Romania. The measurements have been made using two identical USRP equipment, GPS coordinated, and identical HF broadband antennas.

Considering that the level of cyber threats is constantly increasing, a necessary demand emerges from organizations and corporations worldwide to protect their networks against possible cyber-attacks. In the future all malicious actions that occur in cyberspace will continue to alter the way we approach the security of an entire network. The article presents the most stringent need concerning the technical specialization of future officers, highlighting the knowledge entailed in order to better understand the complexity of a mission that takes place in virtual space. Undoubtedly, modern battlefield incorporates a virtual component where nearly all weapons systems rely upon information and communication technologies in order to connect and achieve operational level. The demand for future cyber defence specialists in the military domain reached a high level all over the world, and there will be a challenging process to be able to create a highly skilled workforce to fight against a large scale of malicious activities that have impact upon the national security system.

This paper presents a survey of the models and software applications used in telecommunication networks that can be used to carry out network planning and traffic engineering processes in deployable networks. Deployable networks are intended to provide communication services for organizations with responsibilities for emergency response or for government structures.

A particular solution for the n-th order linear differential equations with constant coefficients that are free of term such as P(x)· e^a·x ·cosⁿx or/and Q(x)·e^b·x· sinⁿx, n∈ N, can be determined based on two elements: the way in which cosⁿx and sinⁿx can develop, and, on the other hand on the way a particular solution for the free terms P(x) ·e^a·x·cosⁿx or/and Q(x)·e^b·x·sin^mx, n ∈N is sought. We can, of course, write the way a particular solution looks also in the case we have a combination of the two terms or more terms of this kind.

The determination of a particular solution for the systems of linear differential equations with constant coefficients that have on the column of free terms functions such as e^a·x·P(x) ·cosⁿx or e^b·x·Q(x)·sinⁿx, or/and e^b·x·Q(x) sinⁿx, n ∈ N, is based on the expansion of cosⁿ x and sinⁿ x, and, on the other hand, on how a particular solution for a column of free terms with functions such as e^a·x·P(x) ·cosⁿx or e^b·x·Q(x)·sinⁿx, n ∈ N, looks like. We can also write the way a particular solution looks like when we have a combination of two or more functions on the form e^a·x·P(x) ·cosⁿx or e^b·x·Q(x)·sinⁿx, n ∈ N in the column of free terms.

The internal combustion engines performance can be increase. The residual gases can be recovered through turbo charging systems because is an important reserve of exhaust gas energy, which can be capitalized. The turbo charging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. The solutions proposed for the theoretical and experimental research is the hybrid turbocharger. The hybrid turbocharger has a double function: to compress the fresh air and to generate electric energy for the vehicle. The compressed fresh air is compress by the rotor wheel of the compressor. The generator which produces the electrical energy is linearly coupled to the rotor on the compressor shaft outside zone. The electrical energy can be used for consumption of the military vehicles or can be stored in to the battery of the vehicle. The military vehicle must have a internal combustion engine or a hybrid engine equipped with a hybrid turbocharger. The article aim is to present the results of the hybrid turbocharger. The simulation was realised with the AMESim Software developed by Siemens. To simulate the exhaust gas energy was used a CIMAT test bed which can provides high pressure air.

The fortified system Árpád, which bears the name of the former Hungarian dynasty set up during World War II, mainly by the Hungarian horthist, stretched for more than 600 kilometers, one third being on the territory of Romania, and the rest on the territory of Ukraine, Slovakia and Poland. In developing this article, I applied the case study as a research method, which allowed me to inventory and evaluate these Horthy fortifications, but also to collect certain data related to their impact on the life of the local community and tourists visiting the area. Throughout the investigations and the documents studied, I found that the Hungarians built in the Rodna Mountains, right in the heart of the mountains, dozens of casemates for defense and attack and, although they had to be destroyed by those who ordered their arrangement, the hasty withdrawal of the Horthyists left some of the bunkers almost intact. The case study shows that the bunkers here were smaller and slightly stiffer. The Hungarians were inspired by the French and Belgian fortifications occupied by the Germans, and the concept was rethought and adapted to the natural conditions in the Carpathians. Following the study, I found that the horthyst defensive system in Transylvania was planned to have 5 types of casemates, depending on their role: surveillance or firing nests or depending on what they housed: ammunition, soldiers or officers. The entire northern group of the Eastern Carpathians bear the traces of armed conflict. Such arrangements can be found in the territories of Rodna, Ilva Mică, Ilva Mare and Mureşenii Bârgăului, areas with a rich natural tourism potential, which, exploited to its true value, could attract many curious and eager tourists to know the history of the places.

The political-military context of the time required finding an urgent solution to stop the mass emigration over the mountains, which decreased the productive and contributing population. Thus, the massive emigration of the Romanian population had to be stopped, the contact too close between the two sides of the Carpathians had to be broken and this permanent popular osmosis was deemed necessary to be established, the borders had to be better secured and under the relation of the economic exchanges, of the smuggling, of the customs regime, of the mercantilism practiced by the regime, it was absolutely necessary to prevent the penetration of the plagues from the East, which became endemic, decimating the population; this led to the establishment of border regiments.

In elaborating this study I used the qualitative method in order to interpret the historical events of the time, an important role in the research undertaken having direct observations made in the field to inventory strategically and militarily favorable geographical areas for the location of the Second Border Regiment, but also in order to evaluate the existing tourist resources, to capitalize on them by the inhabitants of the area and to have an impact on potential tourists. Following the study, I was able to see the beneficial role that the border regiment had on the belonging communes, as well as the positive impact on the community by implementing a much more advanced stage of development.

The paper presents an analytical method for calculating the initial velocity and flight distance of a reusable training-practice mortar round for short distance firing intended as a simulator for mortar teams. This is the first stage in the overall development of the simulator and the results obtained will be used to determine the elements of the mortar’s internal ballistics. The paper also presents a simulation model developed with MATLAB software program, with which calculations were made for 60 mm, 82 mm and 120 mm training-practice mortars.

The paper presents an analytical method for determining the estimated amount of propellant charge for the reusable training-practice mortar round intended for short distance firing, as a part of simulator for mortar crews. For verification of the analytical method an experimental research was conducted where the 82mm training-practice mortar round was fired at a distance of 100 meters. The experimental research and the verification of the statistical hypothesis confirm that the formula can be used to practically determine the required amount of propellant charge.

The interest for GHz frequency range in present wireless communication devices is high. Therefore, a continuous need to observe peculiarities of electromagnetic power deposition in human tissues, when they are exposed to signals in this range, is obvious. In this paper, by using an electromagnetic field simulation software, we aimed to highlight the differences between specific absorption rates (SAR) of energy absorption and their geometric distribution in four cases: at two different frequencies and in two tissue models (plane and anthropomorphic). First step was to design and analyse the electromagnetic field provided by a microstrip antenna, and second step was to compute SAR averaged over 10 g of tissue in two models: a three-layered planar model of human tissues and a homogeneous human head. Similarities and differences are discussed, together with observations regarding temperature increase due to exposures and its trend in different layers of tissues.

The continuous expansion of the semantic web and of the linked open data cloud meant more semantic data are available for querying from endpoints all over the web. We propose extending a standard SPARQL interface with UI and Natural Language Processing features to allow easier and more intelligent querying. The paper describes some usage scenarios for easy querying and launches a discussion on the advantages of such an implementation.

Operations research(OR), also called decision optimization science, is the one that provides mathematical models meant to lead to finding the optimal variant in an economic, military, social, political, etc. type of activity. These are methods with a major potential, highlighted since the emergence of the models used in World War II actions and later in various other fields, especially in western countries. This paper aims to highlight the benefits of using OR techniques over time and especially to highlight its applicability. In this paper we summarize the presentation of the evolution and contributions of Operational Research in various fields until the ‘60s, a future paper will deal with the time frame 1960-2020.

In this paper, the authors want to highlight aspects related to the development, testing and use of an innovative technological product of the electric generator type with magneto, adapted for the production of heat and electricity. Its organology is based on a metal chassis to which is attached the heat engine and the generator with tensioner. The transmission of the rotational movement from the engine to the generator is done with the help of a V-belt. From a constructive point of view, the innovative aspect of the prototype is the adaptation of a moped-type electricity source, called here magneto, on a mobile generator structure that facilitates its independent and separate operation from the motors on which they are assembled. The heat engine has an installation attached to the section to exhaust the fumes resulting from the combustion of fuel. It accumulates heat that it releases into the outside environment. The tensioner allows the connection between the motor and the generator to be broken, allowing the motor to operate separately without generating electricity. The prototype has several constructive and functional advantages, such as: low mass, simple structure, energy efficiency and low operating noise.

In this paper is presented the shell components of Bulgarian 120-mm multiple use short-range training mortar ammunition. These components are constructed and added to the shell of a 120-mm high explosive mortar round. Thus, with minimal financial resources, the 120-mm multiple use shell were designed and constructed so as to be trained recruits in firing the mortar. Strength calculation of the new shell parts of the 120-mm short-range ammunition has been completed. The largest axial stresses that have arisen in the smoke cartridge during a shot have been calculated in order to prevent the self-ignition of the charge.

A schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

The spectacular growth in the use of mobile devices is a natural consequence of the benefits they offer. However, most mobile users grant little importance to the security of information stored, processed and transmitted. Even more, the last two years can be considered years of reference for the mobile security industry - ranging from virulent mobile ransomware attacks to mobile IoT botnets and mobile security breaches through mobile malware, that have redefined security paradigms. It is clear that we are at a point of inflection and transition to another generation of cyber attacks and the tendency is that attacks on mobile devices will expand. The security of mobile devices is a topical issue and the main objective is to educate the user to know the risks to which he/she is exposed to and to offer him/her viable security solutions in order to protect himself/herself against mobile threats. In this article we are going to present some protection and mitigation strategies with recommendations for improvement.

This paper brings in front of the interested researchers using one of the most known and used meshfree method, Element-Free Galerkin (EFG) method, in modelling of a technological process. It is about the deep drawing process of thin plates made of steel or aluminium. The paper gives information both for EFG method and for deep drawing process. The modelling as well the results are presented in a comparative way towards the using of Finite Element Method (FEM). The numerical analysis is based on the Ansys/Ls-Dyna program, in which EFG method is implemented. This numerical method is less known in our country and much less used, in spite of some advantages comparatively with the FEM. Of course, the EFG method is still under developing, but it can be successfully used in many problems. This paper is a proof in this sense and an urge to use the EFG method.

In order to train commanders in the decision making process we cannot rely only on simulation systems. It takes more than war-gaming to be able to train higher-headquarters and a proven solution to achieve that is by using computer assisted exercises (CAX). The higher the headquarters that needs to be trained, the more complicated the systems’ architecture becomes, for both functional area services and simulation systems together with their auxiliary tools. It takes subject matter experts in different domains and up to 18 months to plan a computer assisted exercise. Every stage of the exercise planning process involves using different systems and building their databases. In order for the commanders to be successfully trained in the decision making process, they need to face operational dilemmas. The Main Events List/Main Incidents List (MEL/MIL) planning team’s job during the exercise planning phase is to develop the major events, incidents and injects which will trigger the operational dilemmas and will force the commanders to make decisions in dynamic and fast-paced environments. The MEL/MIL plays a key role in ensuring a successful execution phase of an exercise and this study explains in detail the complex 8 month process of building the MEL/MIL database.

The article is presenting actual state of the art UGVs capabilities and employment in support of naval operations. The paper provides a demanding inquiry of the Black Sea environment and, in this regard, the ways to employ UGVs in support of naval operations conducted in this basin, especially in the grey waters area. As UGVs can be employed alone, as soldiers companion or multiple vehicles, the paper underlines strong points and shortfalls regarding human-vehicle interaction, ”cooperation” between multiple vehicles, and the possibility and opportunity to employ such platforms in conjunction with other manned or unmanned platforms. In the concluding section, the paper gives some directions of research necessary to improve the ability of this vehicle to support naval operations.

Military actions generally unfold rapidly in different operational environments for which the commanding officer has assess the bearing capacity of the prestressed concrete bridges existing in the country’s road network. The bearing capacity is the maximum weight of the predetermined constitution convoy, which may safely circulate on the bridge, in stable conditions, considering the physical condition of the bridge. The paper shows that the bearing capacity will be assessed only through a technical analysis performed by an authorized expert together with a military engineer specialized in genius. This experts report will compare the initial condition of the bridge to the present one. The initial condition is based on the research of the execution design; the year of elaboration; the standard loadings at the moment; proprieties of the used building materials; execution modality, possible alterations occurring during execution as to the initial project. These data, together with the road traffic census, can be obtained from the company administrating the road network where the bridge is located. The current state to be assessed through analysis, calculation and static loading tests, showing if the capacity of the bridge can to support the increase of traffic military vehicle loading and reduction of the bearing capacity due to fatigue phenomena in the reinforcement. The paper proposes that authorities draw up and approve a standard concerning the verification periodicity of the bearing capacity in the existing prestressed concrete bridges.

In this article we present software defined radio (SDR) instrumentation used for interfering or jamming Wi-Fi networks. A Wi-Fi network analyzer application was used together with a low cost, commercially available SDR, Hack RF one, to conduct aimed interference on a 802.11 b/g/n network. A GNU radio flowchart was used to control the radio transceiver (SDR) by emitting a jamming signal aimed towards the targeted client by means of a directional antenna. Various signal bandwidths and distance from the targeted device were tested to characterize the adequate parameters of an effective jamming signal with respect to the calculated signal to noise ratio (SNR). Jamming efficiency was evaluated by means of a Wi-Fi connectivity speed test application installed on the targeted device, in order to measure connectivity degradation if complete jamming was not possible. Results presented suggest that Wi-Fi jamming is possible by means of SDR technology, providing insights on the methodology used and initial optimisation procedures in the test environment.

Spherical shaped objects are some of the most interesting and difficult to measure objects in dimensional metrology. Made of steel, alloys, ceramics, glass, rubber or plastics, they are important elements of precision bearings, pumps, valves, flow meters, medical, measuring, automotive, aerospace and other equipment, used for polishing, grinding, etc. Quality requirements, including their geometric accuracy, are high. A spherical object is defined geometrically by a centre, radius, and spherical spatial surface. There are no uniform rules and definitions for measuring these characteristics, and there is no standard definition of a form deviation. A number of solutions and publications are known to address the problem in practice, which, for the time being, do not allow a uniquely substantiated definition of the derived geometric elements and methods for their measurement. Full measurement of the deviation from sphericity, for example, is impossible. The question of the type of its associated element satisfying certain standard criteria remains open. The accuracy and reliability of measuring spherical objects is related to finding a reasonable solution to the outlined issues.

Gauges are widely used means for alternative control in mass production and, in some cases, in small-scale production. Similar to all measuring devices, their use is accompanied by the well-known errors Type I (α) and Type II (β). A basic requirement when designing gauges is that the values of these errors are equal to those of other measuring devices. Considering the development and improvement of technological processes, at present there is a real possibility to improve some of the gauges’ characteristics. The most important metrological characteristic of the conical gauge is the so-called base distance. The standardized design requirements that are introduced to prevent scrap significantly reduce the production tolerance of the gauge. This not only causes some difficulties in the production of gauges, but also increases the likelihood of incorrectly rejecting conforming parts. The paper presents an opportunity to extend the production tolerance of conical gauges by applying a novel way of determining the nominal diameter of its no-go part, and by calculating theoretically the associated risk Type I (α).

The paper proposes the use of MATLAB simulations as a first step in identifying proper antennas to be used in specific ultra-high frequency (UHF) communication links. Giving that fractal antennas provide interesting features, we aimed at comparing a few of their significant parameters with those of a monopole antenna so as to ensure signal coverage between two real sites situated at 5.82 km distance in a mixture of urban and flat – open terrain conditions. We started from the requirements imposed to the return loss of the antenna and to the link margin, we established their desired thresholds and then computed solutions regarding which antenna type in the set provide the highest received power and on which frequency sub-bands can be successfully used. The studied fractal antenna set were from the series Koch, Koch loop and Sierpinski. The chosen radio link refers to a real situation on the map. Generally, different narrow bands were provided by each antenna regardless of its type, but still, comparing them with the monopole, better solutions could be identified.