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Summary Inverted pendulum on cart belongs to a class of highly non-linear, multivariable and complex system which is currently a keen area of interest for researchers in the field of control engineering and robotics. This paper considers stabilisation and control of inverted pendulum on cart moving on an inclined surface. The task of controlling inverted pendulum on inclined surface is much difficult as compared to that moving on horizontal surface. An offline control of the proposed system has been successfully achieved using proportional-integral-derivative (PID) and fuzzy controllers. A Matlab-Simulink model of the proposed system has been built using mathematical equations derived from Newton's second law. The study compares the proposed techniques in terms of settling time, overshoot, undershoot and steady state error. The simulation results are illustrated with the help of graphs and tables which confirms the validity of the proposed techniques.

Summary Moulded Case Circuit Breaker (MCCB) is a protective device used for low voltage protection in the range of 12–1250 A. It is having fast breaking and making ability due to special contact structure. In case of transformer it is generally placed in secondary side and in case of motor protection it is used as backup protection. The existing design is suffering from chattering of contact tip which lead to erosion and in turn affect electrical life. It also reduces interrupting/breaking capacity of MCCB. In this paper, detailed study of the factors and constraints related to repulsion threshold current ( I rp ) and consistency of magnetic release for 630 A MCCB is carried out using Finite Element tool JMAG to find out limitations and scope of design improvements in existing design. The proposed suggestion is validated by testing.

Summary This paper focuses on corrosion characteristics of cast and forged aluminium 6061 based composites reinforced with TiB 2 particles. Composites were synthesised by in situ technique using potassium hexafluorotitanate salt (K 2 TiF 6 ) and potassium tetrafluroborate (KBF 4 ) halide salts by stir casting route at a temperature of 850 °C. Cast aluminium alloy and its in situ composites were subjected to open die drop forging at a temperature of 500 °C. Both cast and forged alloy 6061 and in situ composites were then subjected to microstructure studies, salt spray test. Salt spray test was conducted as per ASTM B117 standard test procedure using 5% sodium chloride test solution. Result reveals that, forged alloy and its in situ composites exhibited improved corrosion resistance compared to cast ones.

Summary In deregulated rate structure, the performance evaluation of distribution system for energy efficiency includes; loss minimization, improved power quality, loadability limit, reliability and availability of supply. Energy efficiency changes with the variation in loading pattern and the load behaviour. Further, the nature of load at each node is not explicitly of any one type rather their characteristics depend upon the node voltages. In most cases, load is assumed to be constant power (real and reactive). In this paper voltage dependent practical loads are represented with composite load model and the energy efficiency performance of distribution system for practical loads is evaluated in different configurations of 33-node system.

Summary Cloud storage, which can be a surrogate for all physical hardware storage devices, is a term which gives a reflection of an enormous advancement in engineering ( Hung et al., 2012 ). However, there are many issues that need to be handled when accessing cloud storage on resource constrained mobile devices due to inherent limitations of mobile devices as limited storage capacity, processing power and battery backup ( Yeo et al., 2014 ). There are many multi cloud storage applications available, which handle issues faced by single cloud storage applications. In this paper, we are providing analysis of different multi cloud storage applications developed for resource constrained mobile devices to check their performance on the basis of parameters as battery consumption, CPU usage, data usage and time consumed by using mobile phone device Sony Xperia ZL (smart phone) on WiFi network. Lastly, conclusion and open research challenges in these multi cloud storage apps are discussed.

Summary In presence of environmental noise, speakers tend to emphasize their vocal effort to improve the audibility of voice. This involuntary adjustment is known as Lombard effect (LE). Due to LE the signal to noise ratio of speech increases, but at the same time the loudness, pitch and duration of phonemes changes. Hence, accuracy of automatic speech recognition systems degrades. In this paper, the effect of unsupervised equalization of Lombard effect is investigated for Hindi vowel classification task using Hindi database designed at TIFR Mumbai, India. Proposed Quantile-based Dynamic Cepstral Normalization MFCC (QCN-MFCC) along with baseline MFCC features have been used for vowel classification. Hidden Markov Model (HMM) is used as classifier. It is observed that QCN-MFCC features have given a maximum improvement of 5.97% and 5% over MFCC features for context-dependent and context-independent cases respectively. It is also observed that QCN-MFCC features have given improvement of 13% and 11.5% over MFCC features for context-dependent and context-independent classification of mid vowels.

Summary This paper presents an optimal placement methodology of energy storage to improve energy loss minimization through peak shaving in the presence of renewable distributed generation. Storage sizing is modelled by considering the load profile and desired peak shaving. This storage is suitably divided into multiple storage units and optimally allocated at multiple sites with suitable charge discharge strategy. Thus the peak shaving for maximum loss reduction is explored here. Renewable distributed generation (RDG) is modelled based on the seasonal variations of renewable resources e.g ., solar or wind and these RDGs are placed at suitable locations. A high-performance Grey Wolf Optimization (GWO) algorithm is applied to the proposed methodology. The results are compared with the well-known genetic algorithm. The proposed methodology is illustrated by various case studies on a 34-bus test system. Significant loss minimization is obtained by optimal location of multiple energy storage units through peak shaving.

Summary In recent years, the coal mine safety production situation in our country improved year by year, but severe accidents still occurred; the accidents caused great economic loss to the national economy. According to statistical analysis, almost all of the coal mine accidents will expose the hidden danger in before, most of the accidents caused due to safety management not reaching the designated position and the hidden danger management does not take any decision in time. Based on the coal mine safety management holes in our country, the coal mine macro, meso and micro safety management system was established in this paper, which includes meaning and conception of the theories of the macro, meso and micro safety management, and also includes the matching hardware equipment, in order to achieve the hidden danger's closed-loop control and dynamic early warning in the process of coal mine production.

Summary The acceleration and deceleration of trains are essential for satisfactory performance of train services and for effective utilisation of line capacity by railways for a given network. However, it increases the risk of unbalancing the passengers. Therefore, in this paper, the jerk was analysed in the vehicle in order to examine its effect on safety and comfort to the passengers. For the purpose of this analysis, a rake with 24 ICF coaches fitted with CBC (H type tight lock) and low preload draft gear hauled by WDP4 locomotive was considered. It was modelled using Universal Mechanism – a multibody dynamic software. Also, in addition, the vehicle is considered to be subjected to external forces such as rolling resistance, longitudinal wheel resistance, and gravitational force. The tractive and braking efforts for the locomotives are also considered with realistic track conditions between Lucknow and Kanpur of India. The presented results suggest that the CBC with balanced type draft gear reduces the jerk in the train.

Summary Burst pressure is the pressure at which vessel burst/crack and internal fluid leaks. An accurate prediction of burst pressure is necessary in chemical, medical and aviation industry. Burst pressure is a design safety limit, which should not be exceeded. If this pressure is exceeded it may lead to the mechanical breach and permanent loss of pressure containment. So burst pressure calculation is necessary for all the critical applications. To numerically calculate burst pressure material curve is essential. There are various material models which are used to define material curve, amongst them Ramberg–Osgood is very popular. Ramberg–Osgood accurately capture material curve in strain hardening region. This approach is applicable for different material grades. In this paper a finite element method is used to predict burst pressure using Ramberg–Osgood equation. These results are then compared with results obtained from elasto-plastic curve and true stress strain curve. Results obtained by finite element analysis are validated with experimental data which is considered from open literature.

Summary The laying and commissioning of new transmission line is very difficult due to socio-economic problems, like environmental clearances, right of way, etc. Therefore, there is an emphasis on better utilization of available transmission infrastructure. FACTS devices can provide reactive power compensation, transmission capability enhancement, and voltage and stability improvement. FACTS devices operate under the command of system operator who analyses its demand by the data acquired through traditional SCADA system, state estimation algorithms and PMUs. SCADA together with PMU give accurate information about the operational state of power system. This paper proposes a scheme to automate the FACTS devices in collaboration with PMUs in a more efficient way. Highly precised data from PMUs can be fed to intelligent controllers for effective analyzing and automating the FACTS device through control command. Thus, this combination can provide real time control of reactive power, together with enhancement of power handling capability and stability improvement.

Summary The customer's review plays an important role in deciding the purchasing behaviour for online shopping as a customer prefers to get the opinion of other customers by observing their opinion through online products’ reviews, blogs and social networking sites, etc. The customer's reviews reflect the customer's sentiments and have a substantial significance for the products being sold online including electronic gadgets, movies, house hold appliances and books. Hence, extracting the exact features of the products by analyzing the text of reviews requires a lot of efforts and human intelligence. In this paper we intend to analyze the online reviews available for books and extract book-features from the reviews using human intelligence. We have proposed a technique to categorize the features of books from the reviews of the customers. The extracted features may help in deciding the books to be recommended for readers. The ultimate goal of the work is to fulfil the requirement of the user and provide them their desired books. Thus, we have evaluated our categorization method by users themselves, and surveyed qualified persons for the concerned books. The survey results show high precision of the features categorized which clearly indicates that proposed method is very useful and appealing. The proposed technique may help in recommending the best books for concerned people and may also be generalized to recommend any product to the users.

Summary The objective of the paper is to analyse parametric studies and optimum steam extraction pressures of three different (subcritical, supercritical and ultra-supercritical) coal fired power plant cycles at a particular main steam temperature of 600 °C by keeping the reheat temperature at 537 °C and condenser pressure at 0.09 bar as constant. In order to maximize the heat rate gain possible with supercritical and ultra-supercritical steam conditions, eight stages of feed water heater arrangement with single reheater is considered. The system is optimized in such a way that the percentage exergetic losses are reduced for the increase of the exergetic efficiency and higher fuel utilization. The plant cycles are simulated and optimized by using Cycle Tempo 5.0 simulation software tool. From the simulation study, it is observed that the thermal efficiency of the three different power plant cycles obtained as 41.40, 42.48 and 43.03%, respectively. The specific coal consumption for three different power plant cycles are 0.56, 0.55 and 0.54 Tonnes/MWh. The improvement in feed water temperatures at the inlet of steam generator of respective cycles are 291, 305 and 316 °C.

Summary Network-on-Chip has been a growing design paradigm with the rise in Multi-Processor System on Chip (MPSoCs) primarily due to its scalability. While regular meshes (2 or 3-dimensional) are the usual proposal for such a paradigm, a real chip may not follow it. Heterogeneous cores, hardware failures or manufacturing defects can possibly cause irregular topologies in a Network-on-Chip. Selection of a routing algorithm is an important challenge in NoC design as it affects power consumption, communication latency and overall system performance. Routing can be supported in such faulty environment by use of routing tables. But this is not a scalable solution as table size grows with network size. Logic Based Distributed Routing (LBDR) is proposed as a new routing implementation technique which offers compact routing implementation and fault tolerance without use of routing table. In this paper we propose a Hybrid Fault Tolerant Routing Algorithm (HFTRA), which aims to provide fault tolerance support in presence of on-chip link failures. Proposed routing is implemented with LBDR scheme. Analysis of the method has shown the effectiveness of proposed scheme as compared to routing tables when implemented using LBDR.

Summary Selection of a suitable robotic manipulator, out of the available conventional configurations, is one way to employ a robot. However, with the increasing applications of robotic assistance, the concept of task-oriented customised design for prescribed working locations in a given environment, has got attention of several researchers. One of the challenges in this direction is the realisation of specific designs, involving unconventional values of robotic parameters. This paper discusses the D–H parameters based adaptive modules, which can be adjusted according to the given values of robotic parameters. The modules are available in three types with similar architecture. The details of this basic length unit, adaptive twist unit and extended length unit are discussed. Focus of the work is to validate the adaptability of the proposed architecture through the modelling, simulation and development of standard configuration.

Summary Selecting the right vendor is an important business decision made by any organization. The decision involves multiple criteria and if the objectives vary in preference and scope, then nature of decision becomes multiobjective. In this paper, a vendor selection problem has been formulated as an intutionistic fuzzy multiobjective optimization where appropriate number of vendors is to be selected and order allocated to them. The multiobjective problem includes three objectives: minimizing the net price, maximizing the quality, and maximizing the on time deliveries subject to supplier's constraints. The objection function and the demand are treated as intutionistic fuzzy sets. An intutionistic fuzzy set has its ability to handle uncertainty with additional degrees of freedom. The Intutionistic fuzzy optimization (IFO) problem is converted into a crisp linear form and solved using optimization software Tora. The advantage of IFO is that they give better results than fuzzy/crisp optimization. The proposed approach is explained by a numerical example.

Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low–frequency region. Active structural acoustic control commonly aims at the suppression of the far–field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

A traffic data collection system using wireless radio frequency (RF) technologies, e.g. Bluetooth or Wi-Fi, allows for area wide measurement of traffic. This includes travel times on the whole road network. This paper aims to present the technical overview of a newly developed ITS system called DYNAMIC. This system supports indirect data acquisition by moving detectors, processing and provision of floating observer information on the basis of mobile wireless RF data. DYNAMIC consists of sensor hardware and software components like data collection, data import, transport mode detection, data processing, data fusion and visualization.

Model-based energy scenarios are a widely used tool for supporting economic and political decision makers. The results of energy modeling and the conclusions deduced therefrom, however, depend on the model input data derived from framework assumptions about future developments in the embedding society, which are deeply uncertain in the long term. The challenge to deal with this ‘context uncertainty’ in a systematic and comprehensive manner has only recently started to attract intensified attention in energy research; the search for appropriate methods is ongoing. This paper proposes a new concept for the construction of socio-technical energy scenarios, which combines familiar environmental modeling approaches with new developments in qualitative scenario methodology, and demonstrates the possible application of the concept in model-based energy scenario construction. © 2016 Elsevier

According to the Energy Strategy 2050 set forth by the Swiss federal government, Photovoltaic (PV) energy shall make up one fifth of the nation's total energy production in 2050. Such a drastic expansion rate of PV and the resulting excess energy thereof can lead to so-called reverse power flow in the low voltage (LV) grid as demonstrated in previous studies. Power-to-Gas (PtG) represents a suitable storage solution to resolve the situation by absorbing the excess PV energy. This paper presents a qualitative and quantitative feasibility analysis of the PtG technology in the future Swiss LV grid. For this purpose, PtG is integrated in simulation into the grid for absorbing the excess PV energy while producing hydrogen. This hydrogen is assumed to be sold in the mobility sector. Three different operational scenarios are established with respect to the input energy source to the PtG plant, including the excess PV energy, curtailed PV excess energy and PV excess energy plus the energy from the grid. Summing up the results, it can be concluded that the PtG plant is still far from economically viable even though significant improvement can be accomplished to the hydrogen production costs by adopting the active PV curtailment and by purchasing additional energy from the grid. The future study to be undertaken by the authors, with respect to economical viability of the PtG, will include other sources of value, including production of methane as main product, production of oxygen and heat as by-products, and provision of services such as biogas upgrading, frequency regulation and voltage.

Nowadays, due to the pressing global energy demand, a possible source of renewable energy is represented by solar energy. Concentrated solar power (CSP) represents an excellent alternative, or add-on to existing systems for large-scale energy production. In those systems and, particularly, in solar tower plants (STP), mirroring surfaces reflect sunlight, focusing it on the core-component defined as volumetric receiver. Here, a porous structure (absorber) is responsible for converting the solar radiation into heat with the use of evolving air under natural convection. The proper design of this element is essential in order to achieve high efficiencies that can make such facilities extremely advantageous. In this paper, an overview of the different approaches for the numerical modeling developed at the German Aerospace Center (DLR), are presented, based both on detailed and homogeneous representation (discrete and continuum approaches, respectively) of the absorber. The corresponding numerical models were run again and compared where possible, using as reference case pre-exiting experimental evaluation, pointing out shortcomings and differences. Temperature profiles for solid and fluid phase, as well as efficiency value, are used as key parameters in the comparison, showing a substantial gap between numerical and experimental results. This inconsistency can be addressed both to inherent difficulties in the experiments butalso on the lack of a proper characterization of the absorber radiative behavior that directly affects the heat transfer process. This gap is even more pronounced when the use of a continuum approach is considered, due to implicit approximation introduced by the homogeneous representation of the porous volume. For those reasons, a better representation of the radiative heat transfer must be introduced in future conjugate numerical models and the use of a continuum approach can be addressed to a preliminary design procedure, given the possibility to quickly manipulate geometric and thermodynamic parameters of porous structures.

The fuel consumption of future civil aircraft needs to be reduced because of the CO2 restrictions declared by the European Union. A consequent lightweight design and a new engine concept called counter-rotating open rotor are seen as key technologies in the attempt to reach this ambitious goals. Bearing in mind that counter-rotating open rotor engines emit very high sound pressures at low frequencies and that lightweight structures have a poor transmission loss in the lower frequency range, these key technologies raise new questions in regard to acoustic passenger comfort. One of the promising solutions for the reduction of sound pressure levels inside the aircraft cabin are active sound and vibration systems. So far, active concepts have rarely been investigated for a counter-rotating open rotor pressure excitation on complex airframe structures. Hence, the state of the art is augmented by the preliminary study presented in this paper. The study shows how an active vibration control system can influence the sound transmission of counter-rotating open rotor noise through a complex airframe structure into the cabin. Furthermore, open questions on the way towards the realisation of an active control system are addressed. In this phase, an active feedforward control system is investigated in a fully equipped Dornier 728 experimental prototype aircraft. In particular, the sound transmission through the airframe, the coupling of classical actuators (inertial and piezoelectric patch actuators) into the structure and the performance of the active vibration control system with different error sensors are investigated. It can be shown that the active control system achieves a reduction up to 5 dB at several counter-rotating open rotor frequencies but also that a better performance could be achieved through further optimisations.

At present, two-tank molten salt storage systems are the established commercially available concept for solar thermal power plants. Due to their very low vapour pressure and comparatively high thermal stability, molten salts are preferred as the heat transfer fluid and storage medium. Therefore, the development of alternative, more cost-effective concepts is an important step in making thermal energy storage more competitive for industrial processes and solar thermal applications. The paper gives an overview of various storage concepts such as thermocline, floating barrier or embedded heat exchanger that have been developed in recent years. In this context, a description of functionality, a summary of the technical specification and the state of development of each concept is given. The latter includes the next steps and open questions, respectively. Additionally, further research topics, such as the stability of material selections or the functionality of necessary components are presented. In order to answer many of the open questions, a new molten salt test facility called “Test facility for thermal energy storage in molten salts (TESIS)” is under construction at DLR. This facility has two separate sub-systems, which can be operated independently from each other. One system is designed to investigate new single tank storage concepts focusing on the thermocline-filler concept. The other system is a flexible test section for molten salt process technology and component tests, such as valves, solar receiver tubes and instrumentation. Both sub-systems can operate at temperatures up to 560 °C, using nitrate salt as the storage and heat transfer media. Experimental results on the compatibility of filler materials and molten salt will be presented. In addition, the current construction and development status of the facility will be reported. Finally, an overview of current research topics and an outlook related to the test facility is presented.

When the idea of a large space station in Low Earth Orbit (LEO) was conceived in the 1980s, it was primarily planned as an orbiting laboratory for microgravity research. Some even thought of it as an industrial plant in space. Whereas the latter did not materialize because of various reasons, the former is absolutely true when you talk about the International Space Station (ISS). Since the transition to a six astronaut crew in 2009 and the completion of its assembly in 2011, it has been intensively used as laboratory in a wide field of scientific topics. Experiments conducted on ISS have yielded first class results in biology, physiology, material science, basic physics, and many more. While its role as a laboratory in space is widely recognized, the awareness for its potential for preparing future exploration missions beyond LEO is just increasing. This paper provides information on how the ISS programme contributes to future exploration efforts, both manned and unmanned. It highlights the work that has been done or is currently underway in the fields of technology, operations, and science. Further potentials and future projects for exploration preparation are also shown. A special focus lies on experiments and projects primarily funded by the German Aerospace Center (DLR) or with strong German participation in the science team.

There are ambitious greenhouse gas emission (GHG) targets for the manufacturers of light duty vehicles. To reduce the GHG emissions, plug-in hybrid electric vehicle (PHEV) and extended range electric vehicle (EREV) are promising powertrain technologies. However, the battery is still a very critical component due to the high production cost and heavy weight. This paper introduces a holistic approach for the optimization of the battery size of PHEVs and EREVs under German market conditions. The assessment focuses on the heterogeneity across drivers, by analyzing the impact of different driving profiles on the optimal battery setup from total cost of ownership (TCO) perspective. The results show that the battery size has a significant effect on the TCO. For an average German driver (15,000 km/a), battery capacities of 4 kWh (PHEV) and 6 kWh (EREV) would be cost optimal by 2020. However, these values vary strongly with the driving profile of the user. Moreover, the optimal battery size is also affected by external factors, e.g. electricity and fuel prices or battery production cost. Therefore, car manufacturers should develop a modular design for their batteries, which allows adapting the storage capacity to meet the individual customer requirements instead of “one size fits all”.

Implementing a proton exchange membrane fuel cell (PEMFC) into an aircraft environment is a challenging task. In order for aircraft manufacturers and airlines to realize the ecological and economic benefits of this technology, it is necessary to make use of the multiple functions that a fuel cell system can provide. In addition to the main product of electrical energy, the fuel cell is capable of delivering further products, which are useful in an aircraft environment. The waste products – water vapor, heat and oxygen-depleted air (ODA) – at the cathode exhaust are valuable for use on board a commercial airplane. This paper describes the multifunctional approach, points out the advantages of the operation strategy as well as describes a prototype system for the multifunctional use of a PEM fuel cell on board a commercial airplane. The stable operation of the aforementioned system was successfully demonstrated in various tests. The emphasis of the work in question is on water and ODA generation/conditioning.