Abstract: Telecommunications and the Internet are forming an increasingly integrated and global system for processing, storing, transporting information and managing content. At the same time the identification capacity of the Current Internet is running out, Internet architectures are reconsidered for better managing mobility and quality requirements, data handling and security issues, as well as for exploiting the opportunities derived from technological development. The future of the Internet became an important research and standardization area, focusing on service, resource, content and environmental awareness. The paper summarizes the challenges of the Current Internet, draws up the visions and the recent capabilities of the Future Internet, then identifies and clusters the relevant research topics defining the chapters of Future Internet research activity in a layered model from basic research on Internet Science through the Internet Engineering up to Future Internet applications and experiments.
Keywords: Future Internet; Future Internet vision; Future Internet research; Internet Science; Internet Engineering; Internet technologies; Future Internet applications
Abstract: This paper offers an extension of the Liskov substitution principle by means of compatible systems, i.e., right or appropriate or functional systems. The compatible systems are represented by compatible sets. The compatible sets are first defined and the new approach to the mathematical modelling of compatible systems is given. The properties of compatible systems are next presented and applied to the curriculum management in higher education. The theoretical results are exemplified by a case study that discusses the curriculum management of two academic programs of study using the information densities of optional, fundamental and specialized courses. A discussion on the systems compatibility in several fields is included and the importance of our multidisciplinary approach to compatible resources management is highlighted.
Keywords: compatible sets; compatible systems; curriculum management; information density; Liskov substitution principle; mechatronics
Abstract: Incremental Sheet Forming (ISF) is a prosperous forming technique since the end of the 20th Century. Research projects are still active in this topic with the goal to understand more deeply this flexible process and to reach the full industrialisation of it. These investigations are mainly focusing on the one-side version of ISF, however only the two side variants of this process could reach the ultimate flexibility. This paper gives an overview of the recent results and inventions in the field of ISF processes. A new solution of the Two-Sided ISF processes realisation is given. A new approach to the tool-path calculation is outlined which is based on a recently patented system of the authors.
Keywords: incremental sheet forming; die-less forming; tool-path calculation; new solution of the Two-Sided ISF
Abstract: One frequently used method for navigation improvement of web sites is to establish a link between resources such as web pages or files, when it is fully justified. Adaptive web sites may change their display and structure based on a previously recorded user's behavior. The software tool that is described in this paper provides the designer with a graphical presentation of established link proposals between resources. In this way, it supports the designer's decisions referring to establishing new links between resources. Therefore, it makes a contribution to the improvement of the navigational structure of such web sites. This software establishes decision support information and Web designers are able to make business decisions in a relatively easy and visual way.
Keywords: adaptive website; waypost; website design
Abstract: We propose a new algorithm for the detection of ventricular fibrillation (VF) in very short surface electrocardiogram (ECG) episodes. Ventricular fibrillation is the most commonly identified arrhythmia in cardiac arrest patients and can lead to syncope, within seconds. The fast detection of ventricular fibrillation is necessary for prompt defibrillation either with an implantable cardioverter/defibrillator or an automated external defibrillator. Ventricular fibrillation generates stochastic waveforms and recently it has been shown that it exhibits characteristics similar to a non-chaotic signal and contains determinism Probability Density Function (PDF), for the different physical fluctuations was described previously. Accordingly, we describe scaling properties of very short shockable, VF and non-shockable ECG episodes and show that a universal PDF exists for the fluctuations of shockable ECG episodes. We compared the proposed algorithm with nine standard VF detection algorithms. The comparison indicated that our algorithm consistently produced more accurate detection results, then with standard algorithm. We conclude that the proposed method, based on fluctuation analysis, provides new information on the dynamics underlying VF, and allows a better detection compared to other algorithms.
Keywords: electrocardiogram; universal fluctuations; ventricular fibrillation; defibrillation; probability density function
Abstract: Open access to the transmission network represents one of the important tasks for transmission and system operators. Moreover, increases of transactions in markets may lead to transmission network congestion. The approaches proposed for transmission congestion management are: generated power re-dispatching, generators outside the congested area dispatching, or consumed power mitigation for specific buses where it is possible. Transmission costs are able to be computed once the congestion has been solved and it is allocated to generators and consumers, using various methods. This paper analyzes congestion occurrence in case of N-1 contingencies and the allocation of transmission costs, using pro-rata and Bialek methods. The case study is performed for an existing large-scale system – the SouthernWestern side of the Romanian Power System. The results are relevant to for the Romanian TSO (Transmission System Operator) – Romanian Power Grid Company Transelectrica
Keywords: congestion management; transmission system; N-1 criteria; cost allocation
Abstract: The mechanical behavior of any material can be described using several tests, such as, compression tensile, hardness test, etc. In this work, cold and hot compression tests and hardness measurements were utilized. The subject material of this study was the Al 7075 alloy in the initial state (IS) and the multiple forged (MF) state. The cold compression test at room temperature was used to measure the deformation anisotropy on the MF specimen, while the hot compression test results were used as a source data in order to establish the constitutive equation in the wide ranges of working temperature (from 250 to 450°C) and strain rate (from 0.002 to 2 s-1). The homogeneity and structure of the material were evaluated using the Vickers hardness measurements and optical microscopy images.
Keywords: 7075 aluminium alloy; multiple forging; constitutive equations; hot compression test, cold compression test
Abstract: Economic activities are not conducted in a vacuum; external factors may influence production efficiency, and the activity itself may also result in positive or negative impacts. Although disregarding animal welfare aspects appears to hurt only animals that are harmed as a consequence, banning animal torture is as significant a social interest as combating environmental pollution. Therefore, countries and relevant organisations of certain countries (such as the European Union) regulate via provisions the enforcement of animal welfare aspects with regard to economic activities. Below, economic activities covered by animal welfare regulations and the impacts of animal welfare requirements on economic efficiency will be analysed. In most cases, fulfilling such requirements imposes higher costs for the company at issue and, thus, has an inflationary effect on prices similar to levying a tax. As a consequence, animal welfare regulations generally jolt enterprises from the usual minimum cost-maximum return intersection, so animal protection may appear costly at first. However, in the long term in most cases, they do not bring lower revenues because applying the new ‒ often more expensive ‒ method or technology boosts productivity and because the loss of competitors due to compliance failure may increase the market share for complying companies. The consumers’ behaviour is a paradox: on one hand, they are becoming more and more aware of the environmental impacts of their daily lives, whereas on the other hand, concern for the ethical treatment of animals does not always mean changes in purchasing habits. If we look at the production side, animal healthcare statistics prove that the large majority of losses in livestock breeding (mortality, compulsory slaughtering, diseases, poor reproduction and body mass index (BMI) results, medical expenses, etc.) are not caused by obligate pathogens. Most losses are the direct result of diseases due to unfavourable conditions related to animal breeding, feeding and raising or other external factors (power failure, damages from hail, etc.). Through the appropriate keeping and adequate care of animals, sensible animal welfare attitudes and practices may prevent material losses.
Keywords: animal welfare; economics; regulations; negative externality
Abstract: A current source converter (CSC) based static synchronous compensator (STATCOM) is a shunt flexible AC transmission system (FACTS) device, which has a vital role in stability support for transient instability and damping support for undesirable inter-area oscillations in an interconnected power network. A robust pole-shifting based controller for CSC-STATCOM with damping stabilizer is proposed. In this paper, pole-shifting controller based CSC-STATCOM is designed for enhancing the transient stability of two-area power system and PSS based damping stabilizer is designed to improve the oscillation damping ability. First of all, modeling and pole-shifting based controller design, with damping stabilizer for CSC-STATCOM, are described. Then, the impact of the proposed scheme in a test system with different disturbances is demonstrated. The feasibility of the proposed scheme is demonstrated through simulation in MATLAB and the simulation results show an improvement in power system stability in terms of transient stability and oscillation damping ability with damping stabilizer based CSC-STATCOM. So good coordination between damping stabilizer and pole-shifting controller based CSC-STATCOM is shown in this paper for enhancing the power system stability. Moreover, the robustness and effectiveness of the proposed control scheme are better than without damping stabilizer in CSC-STATCOM.
Keywords: A current source converter (CSC) based static synchronous compensator (STATCOM) is a shunt flexible AC transmission system (FACTS) device, which has a vital role in stability support for transient instability and damping support for undesirable inter-area oscillations in an interconnected power network. A robust pole-shifting based controller for CSC-STATCOM with damping stabilizer is proposed. In this paper, pole-shifting controller based CSC-STATCOM is designed for enhancing the transient stability of two-area power system and PSS based damping stabilizer is designed to improve the oscillation damping ability. First of all, modeling and pole-shifting based controller design, with damping stabilizer for CSC-STATCOM, are described. Then, the impact of the proposed scheme in a test system with different disturbances is demonstrated. The feasibility of the proposed scheme is demonstrated through simulation in MATLAB and the simulation results show an improvement in power system stability in terms of transient stability and oscillation damping ability with damping stabilizer based CSC-STATCOM. So good coordination between damping stabilizer and pole-shifting controller based CSC-STATCOM is shown in this paper for enhancing the power system stability. Moreover, the robustness and effectiveness of the proposed control scheme are better than without damping stabilizer in CSC-STATCOM.
Abstract: As the design, development and execution of manufacturing processes continue to spread out across the world, globally distributed enterprises demand new paradigms. Distance collaboration tools are becoming increasingly important in order to maintain synergies between spatially distributed entities enabling effective cooperation over large distances. Virtual Reality (VR) technologies offer unique possibilities for the exchange of planning stages as well as for the identification and collective resolution of problems. This paper discusses the requirements of manufacturing engineers for distance collaboration tools and the challenges associated with the creation of such systems through a working prototype implemented in the VirCA NET frame- work. This pilot solution is a novel application in the field of VR-enhanced spatially distributed collaboration via shared virtual spaces using immersive visualization. Typical scenarios are provided to highlight the capabilities offered by VirCA NET. The paper identifies and classifies the challenges of distance collaboration from a cognitive infocommunications (CogInfoCom) perspective. The challenges are presented with respect to the theoretical background of CogIn- foCom engines and channels emphasising the link between virtual collaboration and the aim of CogInfoCom.
Keywords: Future Internet; 3D Internet; Virtual reality; Remote collaboration; Factory design; Digital factory
Abstract: The essence of obfuscation is to entangle the code and eliminate the majority of logical links in it; that is, to transform the code so that it becomes complex enough for analysis and unauthorized modification. The developed theoretical apparatus allows us to describe an entangled program using concatenation of operational logics of the routines. Consequently, this approach considers not only the instructions or routines themselves, but the actions, or results, they produce. This allows us to consider obfuscation as the process of adding excessive functionality to the program. This paper is unique in presenting an obfuscation method at intermediate code level that is based on the theory of optimizing transformations. The focus is set on generation of fake intermediate level code, suppression of constants, and meshing of control flow transitions.
Keywords: obfuscation; software protection; entangling transformations; fake context; intermediate code
Abstract: This paper proposes to give a brief summary of thermal comfort of soldiers of the 2nd Royal Hungarian Army in Winter Campaign, at the River Don in 1943, and call attention to the importance of the proper clothing and the thermal sensation measured by thermal manikin. The soldiers in the proper sense of heat insulating garments affected no cold, and the effects of climatic factors were also reduced. The 2nd Hungarian Army in the Winter Campaign and military organization has been assigned to very difficult major tasks. Neither the desired equipment nor the clothing arrived as needed due to the overload of railways. The large number of freeze damage is also due to the clothing of soldiers, according also to that our results did not meet the criteria of the extreme variability of the weather conditions and the thermal comfort.
Keywords: clothing; thermal comfort; thermal insulation; thermal manikin
Abstract: This paper analyzes the technical and economic optimum thickness of a thermal insulation layer of an external wall. The observed wall was made of brick and the used thermal insulation material was polystyrene. The heat transfer through the wall takes place in the stationary regime. The mathematical model consists of algebraic equations for investment, exploitation and saving. The graph-analytical method was applied to solve the mathematical model. The applied optimization criterion is the minimum payback period of the investment. The numerical results obtained by the simulation are presented graphically. The optimum thickness of the thermal insulation layer can be seen from the diagram. Based on current prices in Serbia 2013 the techno-economical optimum thickness of thermal insulation layer (polystyrene) is 9 cm. The minimum payback period is 1.96 years.
Keywords: optimum; mathematical model; thermal insulation; criterion
Abstract: Nowadays, the DC motors have been replaced by induction motors in most of the industrial applications. Substantially, Induction motors are single speed, but they can produce high power density in a wide range of speed by applying new drive controllers based on constant V/f, DTC and vector control theory. Electric motors control is mainly accomplished by power electronic drives based on control schemes like constant v/f. However, the challenge of torque generation with fast time response and high accuracy was met by using the controllers based on vector control and DTC. In applications like electric train, generation of torque with rapid time response is so vital. As an example, in Anti skid-Anti slid system, the generated torque should vary between zero and the desirable value quickly to prevent the electric train from slip and the wheels from skidding on the rail. However, the accuracy of the torque magnitude due to its high value is not an important issue and most of the time, errors up to 3 percents in the generated torque is acceptable. In this paper, the control systems used in constant v/f drives are modified in order to generate torque with fast time response and acceptable accuracy. Control systems stability is an essential concern in electric drives and is arisen from the complexities in the controller’s process and the time delays. In the proposed system, by simplification of the drive controllers, the instability problem of the control units is eliminated which in turn reduces the calculation time delays and results in torque generation with appropriate time response. Furthermore, the overall cost of the drive system is reduced considerably.
Keywords: electric drive control; electric train; induction motor; Anti skid-Anti slid system
Abstract: Various hardness test methods have been used to determine the polymer materials resistance to local plastic deformation in scientific community. The most commonly used method is Vickers microindentation. However, it is of crucial importance to fully understand the influence of the indentation load, since its value influences the obtained result. In this paper, two commercial PMMA dental reline resins in untreated and microwave treated condition have been tested. Vickers microindentation with different loads has been used to assess the materials microhardness: 30, 50, 70, 200, 300 and 500 gf. One way ANOVA statistical analysis followed by Tukey’s test was used to determine the statistical differences between various groups. Finally, three models that quantitatively describe load-dependence of the measured Vickers hardness values were used: Meyer’s law, PSR and modified PSR model. It was found that the optimal load for determining PMMA dental reline resins in both untreated and microwave treated conditions is 300 gf. This value may be regarded as loading independent hardness, or HLIH. At lower loads, a more or less pronounced indentation size effect was noticed, while at higher loads, forked crack development leads to an unreliable indentation diagonal measurement and therefore an unreliable microhardness result. The most adequate load-dependence model was found to be modified PSR, that takes into consideration the surface stresses induced by specimen preparation by grinding.
Keywords: Vickers microhardness; indentation size effect; poly(methyl methacrylate); microwave irradiation