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The e-learners’ excellence can be improved by recommending suitable e-contents available in e-learning servers that are based on investigating their learning styles. The learning styles had to be predicted carefully, because the psychological balance is variable in nature and the e-learners are diversified based on the learning patterns, environment, time and their mood. Moreover, the knowledge about...
Distortion is a severe problem in weld products. It depends on various process parameters like plate thickness, current, voltage, type of weld joint and restraints put on. If distortion is not properly dealt during welding then the product may become useless from geometric accuracy point of view. In the present study, a 3-D coupled transient thermal analysis model with auxiliary side heating (parallel...
Use of organic refrigerants such as Hydrochlorofluorocarbons and Chlorofluorocarbons have been criticized for their adverse impact on the Earth’s protective ozone layer and for their significant global warming potential (GWP). CO2 has been receiving great concern as an alternative refrigerant. Cascade refrigeration systems employing CO2 are used for low temperature applications. Being a low critical...
The problem of fluid flow and heat transfer was studied for flow inside twisted duct of square cross-section. Three-dimensional numerical solutions were obtained for steady fully developed laminar flow and for uniform wall heat flux boundary conditions using commercially available software. Reynolds number range considered was 100–3000. Twist ratio used are 2.5, 5, 10 and 20. Fluids considered are...
Some new invariants like chain string, link identification string, loop participation of joint frequency string and loop size frequency string of simple jointed kinematic chains are presented. The first step of the proposed method is to identify all possible loops of a kinematic chain and then these new invariants are developed. A modified loop-joint approach is proposed in this work as compared to...
A numerical study on the effect of complex fracture aperture geometry on propagation of thermal front in a coupled single fracture–matrix system has been carried out. Sinusoidal and logarithmic functions have been used to capture the variation in fracture aperture. Modifications have been made to existing coupled partial differential governing equations to consider the variation of fracture aperture...
This paper deals with the flexural vibrations of composite poroelastic solid cylinder consisting of two cylinders that are bonded end to end. Poroelastic materials of the two cylinders are different. The frequency equations for pervious and impervious surfaces are obtained in the framework of Biot’s theory of wave propagation in poroelastic solids. The gauge invariance property is used to eliminate...
This paper deals with multi-objective optimization in gait planning of a 7-dof biped robot during its double support phase, while ascending and descending some staircases. For determining dynamic balance margin of the robot in terms of zero-moment point, its double support phase has been assumed to be consisting of two single support phases on non-coincidental parallel surfaces. Thus, dynamic balance...
Dual fuel engines are being used these days to overcome shortage of fossil fuels and fulfill stringent exhaust gas emission regulations. They have several advantages over conventional diesel engines. In this context, this paper makes use of experimental results obtained from a dual fuel engine for developing models to predict performance and emission parameters. Conventional modelling efforts to understand...
An experimental system was built to measure the gas (nitrogen and helium) flow characteristics in circular microchannels with diameters of 50, 20 and 5 μm. The Reynolds number of the flow was controlled in the large range of 15 to 2550. The highest Mach number could reach a magnitude of 0.625 and the highest Knudsen number was over 0.021. Four available empirical correlations were comparatively studied,...
This paper aims to improve the clustering of vehicles by using fuzzy logic in Vehicular Ad-Hoc Networks (VANETs) for making the network more robust and scalable. High mobility and scalability are two vital topics to be considered while providing efficient and reliable communication in VANETs. Clustering is of crucial significance in order to cope with the dynamic features of the VANET topologies....
In this paper, rigorous analytical derivation of the coefficients of optimal current waveform for class-F power amplifier (PA) up to fourth harmonic (dc, 1st, 2nd and 4th harmonic) is presented. The coefficients of the optimal current waveform along with related maximum attainable efficiency are provided in closed form. The results obtained are also of interest for the inverse class-F, in the case...
In this paper, a robust H2/H∞ control with regional Pole-Placement is considered for tool position control of a nonlinear uncertain flexible robot manipulator. The uncertain nonlinear system is first approximated by Takagi and Sugeno’s (T–S) fuzzy model. To achieve a better tracking, an extra state (error of tracking) is then augmented to the T–S model. Based on each local linear subsystem with augmented...
The effect of melting and solute dispersion on heat and mass transfer in non-Darcy fluid flow over a vertical surface has been studied numerically in the present article. The flow is assumed to be laminar and steady state. Using similarity transformations, the governing boundary layer equations are transformed into self-similar nonlinear ordinary differential equations, which are then solved by using...
Fibre Bragg Grating (FBG) sensors are the most recent type of fibre optic sensors, which are gaining importance in the field of structural health monitoring of civil infrastructure. These are proven to be more versatile due to their distinct advantages such as high sensitivity, immunity to electromagnetic interference, ease of multiplexing and remote sensing. These are suitable for the short-term...
Biochemical processes occur through intermediate steps which are associated with the formation of reaction complexes. These enzyme-catalyzed biochemical reactions are inhibited in a number of ways such as inhibitors competing for the binding site directly, inhibitors deforming the allosteric site or inhibitors changing the structure of active substrate. Using an in silico approach, the concentration...
The objective of contrast operators consists in normalizing the gray levels of the input image for the purpose of avoiding abrupt changes in intensity among different regions. In this paper morphological transformations are used to detect the background in color images characterized by poor lighting. The disadvantage of contrast enhancement as studied in previous contrast enhancement algorithms is...
The determination of thermal conductivities of a composite lamina is of paramount importance in the effective design and application of composite materials. The thermal conductivity of a lamina along the fibre direction can be easily estimated from the Rule of Mixtures but, the thermal conductivity in the transverse direction which depends on many factors need to be determined effectively. The transverse...
In this paper, we consider the system of linear equations A x ~ = b ~ , where A ∈ ℝ n × n is a crisp H-matrix and b ~ is a fuzzy n-vector. We then investigate the existence and uniqueness of a fuzzy solution to this system. The results can also be used for the class of M-matrices and strictly...
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