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This article proposes a design and implementation of array Microstrip Patch antenna of configuration 2 × 2 at an operating frequency of 3.5 GHz. The proposed design takes a dimension of 80 mm × 92 mm × 1.6 mm with four radiating elements arranged in rectangular form with an optimized separation between the patches. All the radiating elements were connected through a corporate series network with an inset feed to have better impedance matching. The model gives an efficiency of 90.99% with a bandwidth of 510 MHz and with fractal configuration, the bandwidth further enhances to 1.12 GHz. The maximum gain measured was found as 11.01 dBi at θ = 10° and ɸ = 360° and 10.45 dBi with fractal configuration. The designed antenna is proposed to be used in RADAR which will be used in the intelligent transportation system for the detection of nearby (short-range) vehicles in the blind zone. This kind of Radar also finds its application in collision avoidance and activating airbags/break boosting and thus helping mankind by saving lives. The article gives an idea of the use of an array antenna in intelligent transportation system for better gain and efficient results.

In this paper, we present a computationally efficient trajectory optimizer that can exploit GPUs to jointly compute trajectories of tens of agents in under a second. At the heart of our optimizer is a novel reformulation of the non-convex collision avoidance constraints that reduces the core computation in each iteration to that of solving a large scale, convex, unconstrained Quadratic Program (QP). We also show that the matrix factorization/inverse computation associated with the QP needs to be done only once and can be done offline for a given number of agents. This further simplifies the solution process, effectively reducing it to a problem of evaluating a few matrix-vector products. Moreover, for a large number of agents, this computation can be trivially accelerated on GPUs using existing off-the-shelf libraries. We validate our optimizer's performance on challenging benchmarks and show substantial improvement over state of the art in computation time and trajectory quality., 8 pages

This letter considers a point-to-point data transmission scheme over a fixed number of slots where the energy harvesting transmitter operates in harvest-use-store (HUS) mode and an imperfect supercapacitor with storage loss and energy leakage loss is used as an energy storage device. For these settings, the dynamic programming (DP) method is known to achieve the optimal throughput, but the ‘ curse of dimensionality’ necessitates the search of schemes that allow for an improved performance-complexity trade-off. The work focuses on deriving a computationally efficient online transmission policy that achieves the optimal or near-optimal throughput. This letter presents a novel computationally efficient uniform thresolding based online transmission policy that achieves near-optimal throughput. The work also presents numerical results which demonstrate that the proposed policy with supercapacitor-based energy storage achieves better or the same performance as compared to the battery-based energy storage, thus allowing for a longer lifetime of sensor networks.

The tuning of charge carriers in graphene is essential for its realization as high-performance electrode in various electronic and optoelectronic devices. In this study, we used chemical doping approach to alter the electronic properties of chemical vapor deposition (CVD) grown single-layer graphene (SLG) via coating of octadecyltrimethoxysilane (OTS) self-assembled monolayer (SAM). Raman spectra and electrical measurements showed that the OTS treatment on SLG induces p-type doping. The Raman peaks positions and the values of I2D/IG were examined for pristine and OTS doped graphene, which revealed the charge transfer from graphene to OTS molecules. The electrical characterization demonstrated that the OTS treatment can significantly shift the charge neutrality point towards the right side, which confirmed the p-type doping. This study suggests that the electronic properties of CVD-grown graphene could be modulated by OTS treatment and provides a promising idea for the development of graphene-based electronic devices.

The objective of this research article is to perform the detailed study of femur bone by using finite element analysis method on ANSYS software. For this purpose literature review studied from 1980 to 2019. In previous studies the researcher did modal and structural analysis of femur bone at different boundary conditions. In this research modelling of femur bone was done on solid works taking the drawing dimensions of CT scanned femur bone and this model of femur bone was also scaled to 90% to 110% to because of anthropometrics. Natural frequencies of different size femur bone studied at different boundary conditions. Structural analysis has been performed and mode shapes at different natural frequencies studied. In this project the fracture has been identified and for healing the support plate and screws designed and fixed to fractured bone. Further structural and modal analysis done for varying the support plate material and strength analysis was performed. In order to enhance better healing and reducing loss in bone mineral density some improved materials has been found for surgical implants give scope for future study.

The work presents a novel computationally efficient transmission policy for throughput maximization over point-to-point sensor links employing harvest-use-store protocol with finite storage capacity battery. In these settings, under finite averaging duration constraint, the stochastic dynamic programming (SDP) technique provides the optimal solution for throughput maximization, but the implementation complexity for SDP is prohibitively large. Thus, there is a need to explore new solutions that can provide near-optimal throughput with lower implementation complexity. The work in this paper presents a adaptive transmission policy based on uniform thresholding that achieves a near-optimal throughput obtainable by SDP. Quantitative comparison with optimal online policies shows that the proposed policy attains performance close to SDP with lower implementation complexity.

In this paper, we investigate the variation of ionospheric total electron content (TEC) derived from global positioning system (GPS) observations at a low latitude station in Magna (Station code: RASH, Geographic coordinate: 28°17′N, 34°47′E), Saudi Arab. The study includes a linear regression method for validating the relationship between regional TEC and solar indices during the period 2015–2017 representing the descending phase of 24th solar cycle. The results show a relatively better agreement of diurnal variation of TEC with solar extreme ultraviolet (EUV) flux (0.1–50 nm wavelength) as compared to the Sunspot number (SSN) and 10.7 cm radio flux (F10.7). Interestingly, the seasonal variation shows a higher magnitude of TEC during the winter season as compared to the summer and fall equinox seasons, which is reported as the winter anomaly over the low latitude region. The correlation coefficient between VTEC and solar indices is also higher during the winter as compared to summer season. Concerning diurnal variability, the results show a higher correlation coefficient during the local noon time (1200SAST) that gradually descends towards evening time (1800SAST) and after that decays during the night time (2100SAST) to attend the diurnal minima. This manifests the diurnal solar irradiance dependence over the low latitude region. Moreover, the lesser agreement in the linear relationship between the TEC and solar indices during the year 2015 than the year 2017 substantiates the dependence of TEC magnitude and vitiations on solar activity. The outcomes from this strengthens the regional understanding and modeling of ionospheric parameters and would complement towards the global efforts for modeling and mitigating the ionospheric effects on transionospheric communication, timing and navigation services. Above all, the intents of this study are in line with the augmentation of aviation services performances in Saudi Arab that plays a vital role in the international civil aviation and logistic trade due to its central geographic location.

In typical urban or suburban environments, multipath poses a serious threat to the accuracy of position determined by a global navigation satellite system (GNSS) receiver. In this paper, a novel multipath mitigation technique is proposed for general multipath scenarios encountered in the urban settings. In the proposed technique, a double differentiated correlation function based histogram output is used to estimate the code delay. It is shown that the proposed technique provides significant improvements over the current state of the art techniques like high resolution correlator/double delta correlator and narrow correlator. The results hold for general multipath models for the mobile-satellite channels. The performance guarantees include closed form expressions for the probability of correct delay estimate and simulation results for the average range error variation with respect to carrier to noise ratio (CNR), signal bandwidth and different channel settings.

This paper highlights the hardware implementation of orthogonal frequency division multiplexing (OFDM) based joint radar and communication (RADCOM) system for the vehicular application. Improvement of the communication system due to the application of OFDM is well established and the same advantages can be exploited to enhance the radar performance. The frequency diversity of the OFDM signal improves the radar performance significantly. This motivates the authors to develop a RADCOM system based on OFDM waveform. This paper includes the performance analysis of the OFDM based RADCOM system under the dynamic vehicular channel conditions. Communication system performance is analyzed based on the bit error rate (BER) and the performance of the radar system is evaluated based on target detection.

Cement stabilization is the most frequently used technique to enhance the mechanical properties of recycled materials. Reclaimed Asphalt Pavement (RAP) and Recycled Concrete Aggregate (RCA) are abundantly available recycled materials and utilization of these materials in road construction is a sustainable and eco-friendly process. However, the advantage of cement stabilization of RCA over RAP and blending with Conventional aggregates (VA) as a base and subbase course material at different stabilization levels is unknown. In the current study the same is investigated by stabilizing mixes with cement contents varying from 2 to 6% and blending with VA compared in terms of physical properties, compaction characteristics, and the performance tests like Unconfined Compressive Strength (UCS), Indirect Tensile Strength (ITS), and Modulus of Elasticity (E) at 7 days of curing period. From the results, it is observed that recycled aggregate blends need higher cement contents to satisfy the specifications as base layer for high volume roads and the stabilization of RCA is more pronounced compared with RAP. Significant improvement in strength is observed when blended with VA at all cement contents. However, RCA mixes achieved maximum strength at equal proportions of RCA and VA. No particular trend is observed in Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) for RCA blends due to the non-homogeneous distribution of mortar. The Elastic modulus of the RCA mixes declines with RCA content at higher cement content due to brittle nature. Summarily, 25% RAP, 25% RCA and 50% RCA blends at 6% cement performed well.

Cyanobacteria are an immense source of innovative classes of pharmacologically active compounds exhibiting various biological activities ranging from antioxidants, antibiotics, anticancer, anti-inflammatory to anti-Alzheimer's disease. In the present study, we primarily targeted the inhibition of Beta-site amyloid precursor protein cleaving enzyme-1 (BACE1) by a naturally occurring cyanobacterial protein phycoerythrin (C-PE). BACE1 cleaves amyloid-β precursor protein (APP) and leads to accumulation of neurotoxic amyloid beta (Aβ) plaques in the brain, as an attribute of Alzheimer's disease (AD). Inhibition of BACE1 was measured in terms of their association and dissociation rate constants, thermodynamics of binding using surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). The kinetic parameters for enzyme activity were also measured using synthetic decapeptide as a substrate. We further validated the potential of PE by in-vivo histopathological staining of Aβ aggregate mutant Caenorhabditis elegans CL4176 by Thioflavin-T. The present studies pave the way for the application of naturally occurring C-PE as a putative therapeutic drug for the AD.

In this paper we propose a distributed locality sensitive hashing based framework for image super resolution exploiting computational and storage efficiency of cloud. Now days huge multimedia data is available on the cloud which can be utilized using store anywhere and excess anywhere model. It may be noted that super resolution is required for consumer electronics display devices due to various reasons. The propose framework exploits the image correlation for image super resolution using locality sensitive hashing (LSH) for manifold learning. In our work we have exploited the benefits of manifold learning for image super resolution, which in-turn is a highly time complex operation. The time complexity is involved due to finding the approximate nearest neighbors from trillion of image patches for locally linear embedding (LLE) operation. In our approach it is mitigated by using a distributed framework which internally uses hash tables for mapping of patches in the target image from a database of internet picture collection. The proposed framework for super resolution provides promising results in comparison to existing approaches.

The multiple input multiple output (MIMO) technology is a key technology for fourth generation (4G) and beyond wireless communications. The MIMO exploits the space diversity to improve performance as well as augment its capacity. Long term evolution (LTE), the dominant 4G standard, operates in diverse MIMO modes, including spatial multiplexing, spatial diversity, and beamforming techniques to combine the advantages of spatial diversity and spatial multiplexing. This article discusses the various modes in LTE and analyses the performance of the single input single output (SISO) and the single input multiple output (SIMO) modes with selection combining (SC) and maximal ratio combining (MRC) at the receiver end. multiplexing (OFDM) is the multiple. The analysis was done on different values of power decay factor and the different number of channel taps. The performance of MIMO configurations for varying power delay profiles and resolvable paths has been analyzed. It is inferred that the higher number of resolvable paths and a low scattering propagating environment augments the performance.

The performance of organic electronic devices strongly depends on nanoscale structure/macroscopic morphology of organic semiconducting material. In this paper, we have examined the solubility dependent crystallinity and electrical charge transport properties of poly (3-hexylthiophene) (P3HT). We have used three different solvents, toluene (TLN), chloroform (CF) and dichloromethane (DCM) to dissolve the same amount of P3HT. We observed significant change in structure, morphology and optical properties of P3HT in these solvents. We obtained highly crystalline and oriented film morphology of P3HT in ultrasonicated DCM solution. Structure and morphology of films have been studied using grazing incidence X –ray diffraction (GIXD) and atomic force microscopy (AFM). The electrical charge transport properties of the films casted using TLN, CF and ultrasonicated DCM have been investigated with Schottky diode configuration ITO/P3HT/Al. The current density – voltage (J–V) characteristics are used for extracting the device parameters. The solubility driven trap density is also calculated by J–V characteristics at room temperature. We observed that highly crystalline P3HT in case of DCM has one order of magnitude less traps than P3HT (CF).

Trajectory optimization problems under affine motion model and convex cost function are often solved through the convex-concave procedure (CCP), wherein the non-convex collision avoidance constraints are replaced with its affine approximation. Although mathematically rigorous, CCP has some critical limitations. First, it requires a collision-free initial guess of solution trajectory which is difficult to obtain, especially in dynamic environments. Second, at each iteration, CCP involves solving a convex constrained optimization problem which becomes prohibitive for real-time computation even with a moderate number of obstacles, if long planning horizons are used.In this paper, we propose a novel trajectory optimizer which like CCP involves solving convex optimization problems but can work with an arbitrary initial guess. Moreover, the proposed optimizer can be computationally upto a few orders of magnitude faster than CCP while achieving similar or better optimal cost. The reduced computation time, in turn, stems from some interesting mathematical structures in the optimizer which allows for distributed computation and obtaining solutions in symbolic form. We validate our claims on difficult benchmarks consisting of static and dynamic obstacles.

Bord and Pillar method of underground mining has been used extensively to develop Indian coal seams into pillars and galleries. This results in only 20–30% recovery of coal and rest coal remain locked up in developed pillars. Indian coalfields are famous in the world for its uniqueness and complexity of the geomining conditions which makes the extraction of the locked-up coal pillars a difficult and hazardous activity using different underground mining methods. Indian mining industry has introduced mechanisation since last 10 years to deal with the various underground rock mechanics issues in order to improve the efficiency and safety during recovery of locked-up coal pillars. But mere introduction of mechanisation did not solve all the rock mechanics problems due to requirement of indigenous design of different involved geotechnical elements for Indian geomining conditions. CSIR-CIMFR is a national research organisation engaged in improving conditions of underground coal mines. It has developed rock mechanics advances, namely, design of irregular shaped heightened rib/snook, roof bolt-based breaker-line support, warning limit of roof sagging, and cut-out distance for continuous miner-based mechanised depillaring. This chapter presents the developments made and highlights challenges to pursue future research studies for mechanised depillaring-based mass coal production from Indian underground mines.

In this paper, we consider the problem of tracking a ground vehicle with a fixed-wing aerial vehicle (FWV) equipped with a downward-facing camera. The complexity of the problem stems from the highly nonlinear kinematics of the FWV and the stall speed constraint. We propose a Model Predictive Control (MPC) approach for this problem that has two main contributions. Firstly, we model the tracking requirement through a novel constraint function that relates FWV’s position and orientation to the field of view of the camera. Secondly, we make a case for reformulating the underlying optimization of the MPC as an unconstrained problem and solving it through the state of the art gradient descent variants like ADAM and RMSProp. Specifically, we show the real-time performance of this optimizer while achieving good tracking performance under various kinematic constraints. We validate our MPC through extensive simulations, specifically highlighting the 3D spiral-like trajectories obtained for the FWV when tracking a slow-moving ground vehicle. We also present a quantitative analysis of the efficacy of the different gradient descent variants.

Autonomous cars and fixed-wing aerial vehicles have the so-called non-holonomic kinematics which non-linearly maps control input to states. As a result, trajectory optimization with such a motion model becomes highly non-linear and non-convex. In this paper, we improve the computational tractability of non-holonomic trajectory optimization by reformulating it in terms of a set of bi-convex cost and constraint functions along with a non-linear penalty. The bi-convex part acts as a relaxation for the non-holonomic trajectory optimization while the residual of the penalty dictates how well its output obeys the non-holonomic behavior. We adopt an alternating minimization approach for solving the reformulated problem and show that it naturally leads to the replacement of the challenging non-linear penalty with a globally valid convex surrogate. Along with the common cost functions modeling goal-reaching, trajectory smoothness, etc., the proposed optimizer can also accommodate a class of non-linear costs for modeling goal-sets, while retaining the bi-convex structure. We benchmark the proposed optimizer against off-the-shelf solvers implementing sequential quadratic programming and interior-point methods and show that it produces solutions with similar or better cost as the former while significantly outperforming the latter. Furthermore, as compared to both off-the-shelf solvers, the proposed optimizer achieves more than 20x reduction in computation time.

Damage in the form of delamination and debonding are the most common failure modes observed in polymeric composites used for high end structural applications. The principal aim of this work is to investigate the fracture behaviour of Ultra High Molecular Weight Polyethylene (UHMWPE) and p-aramid based hybrid composite. In this work, an optimized processing condition based on highest flexural strength has been evaluated using Box-Behken design of experiment method to fabricate the hybrid composite. Based on most optimized processing conditions process variable such as 14.2 MPa for pressure, 120 oC for temperature and 12.7 minutes for time, compression moulded hybrid composites were prepared and the same were studied in detail for their interlaminar fracture toughness. In the present study, a finite notch radius that varied from 110 – 750 µm has been employed. The fracture toughness/resistance (K1c) of the material has been evaluated and analyzed by investigating the influence of varying notch root radii. The results obtained from the analysis showed that the critical notch root radius of the hybrid composite is around 340 µm. The load displacement data of three point bend test with varied crack length are used to evaluate plain strain fracture toughness (K1c). The K1c has been found 1.5 MPa√m for the KQ values derived from specimens with a/W of 0.45-0.55.

Recently, graphene and other two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been widely explored due to their unique optical, mechanical, electrical and sensing properties for versatile electronic and optoelectronic applications. The atomically thin layers of TMDC materials have shown potential to replace state-of-the-art silicon-based technology. Graphene has already revealed an excess of new physics and multifaceted applications in several areas. Similarly, mono-layers of TMDCs such as molybdenum disulfide (MoS2) have also shown excellent electrical and optical properties possessing a direct band-gap of ∼1.8 eV combined with high mechanical flexibility. In contrast to semi-metallic graphene, the semiconducting behavior of MoS2 allows it to overcome the deficiencies of zero-band-gap graphene. This review summarizes the synthesis of 2D MoS2 by several techniques, i.e., mechanical and chemical exfoliation, RF-sputtering, atomic layer deposition (ALD) and chemical vapor deposition (CVD), etc. Furthermore, extensive studies based on potential applications of MoS2 such as the sensor, solar cells, field emission and as an efficient catalyst for hydrogen generation has been included. Theoretical aspects combined with the experimental observations to provide more insights on the dielectric, optical and topological behavior of MoS2 was highlighted.

This paper presents the design and performance analysis of Flower Pollination Algorithm (FPA) based Proportional Integral Derivative (PID) controllers for Automatic Generation Control (AGC) of an interconnected power system. A two area thermal system with governor dead-band nonlinearity is considered for the design and analysis purpose. A different kind of approach is made to design a multi-objective function which contains weighted performance functions such as ISE, IAE, ISTE, ITAE. These weights are the functions of system response. It is noticed that the dynamic performance of new objective optimized PID controller is better than the others mentioned in the literature. The objective function also includes performance response for various percentage of loads, so that obtained gain parameters are optimal for dynamic load conditions. Keywords: Flower pollination, Weights, Dynamic loading, Automatic generation control, Two area thermal system, Governor dead-band nonlinearity

In an energy harvesting communication system, the main challenge is to improve network lifetime and maximize throughput by allocating optimal power over a finite span of time, with varying channel and energy. Considering (1) causal state information (SI) of channel and energy (CSI and ESI) and (2) energy storage device imperfections, the problem of power allocation is solved using dynamic programming. As compared to the battery, the supercapacitor is a good alternative for network lifetime improvement, but the imperfections hinder the performance. In this paper, imperfections (storage inefficiency and energy leakage equation) are modeled for supercapacitor and battery. We consider a constant leakage rate for battery. Also, the imperfections of battery and supercapacitor are compared to find which imperfection of supercapacitor is a bottleneck in system performance in different settings (varying channel conditions). The analysis is supported by numerical results.

As a power system turns out to be all the more heavily loaded and more unpredictable, maintaining stability becomes a difficult issue. In this paper, we propose an optimal control procedure for power system adjustment utilizing a proportional-integral-derivative (PID) controller in a coordinated power system. In modern applications, the most generally utilized controller is the PID controller, which necessitates productive techniques to control the distinctive parameters of the plant. The proposed strategy uses the particle swarm optimization algorithm-based way to deal with producing the optimal tuning parameters. This paper investigates the execution of the power system and dynamic execution of the controller is compared with the conventional controller with approval of the adequacy of the proposed mixture controller. Experimental results demonstrate that the proposed system has upgraded the system stability of the power system all the more adequately existing systems.

This paper deals with design of integer and non-integer IMC based controllers for automatic generation control of two area power system using the simplified decoupling technique. A two area non-reheated interconnected thermal power system is considered for decentralised controller design. The coupling among areas are the main hurdle encountered in the design of controller. Hence, the idea of simplified decoupling technique is introduced to decouple the two area power system into two equivalent independent SISO systems. Integer and non-integer internal model control (IMC), are independently designed for each area based on decoupled systems. The performance of two area power system equipped with proposed controller is analysed through MATLAB. Simulation results show that proposed controller maintains robust performance and can minimize the load fluctuations. Finally, the method is extended to three area power system.

As the need for mobile services continues to explode, mobile wireless networks must expand greatly their capacities. The capacity of 4G cellular wireless networks like LTE-A (Long Term Evolution Advanced ) can be increased by larger bandwidth, higher number of antennas for more spatial multiplexing, reuse of radio cells and in general optimisation of the network configuration. Methods of capacity expansion divide into three general categories: the deployment of more radio spectrum, more intensive geographic reuse of spectrum and increasing the throughput capacity of each MHz of spectrum within a given geographic area. The paper describes these several basic methods to intensify mobile wireless capacity. The potentially higher capacity will be achieved only if the whole wireless network can be more flexible to the existing real environment at any time. Appropriate linear or nonlinear flexible AMC (adaptive modulation and coding) techniques which are able to identify these changes are described for wideband linear power amplifier, multiple input multiple output antenna systems, heterogeneous networks and self-organising networks including the corresponding realisation and performance aspects.

It is an essential to tune the charge carrier concentrations in semiconductor in order to approach high-performance of the electronic and optoelectronic devices. Here, we report the effect of thin layer of gold (Au) metal on few layer (FL) molybdenum disulfide (MoS2) by atomic force microscopy (AFM), Raman spectroscopy and electrical charge transport measurements. The Raman spectra and charge transport measurements show that Au thin layer affect the electronic properties of the FL MoS2. After deposition of Au thin layer, the threshold voltages of FL MoS2 field-effect transistors (FETs) shift towards positive gate voltages, this reveal the p-doping in FL MoS2 nanosheets. The shift of peak frequencies of the Raman bands are also analyzed after the deposition of Au metal films of different thickness on FL MoS2 nanosheets. The surface morphology of Au metal on FL MoS2 is characterized by AFM and shows the smoother and denser film in comparison to Au metal on SiO2.

This paper presents a channel estimation and tracking method for correlated block-fading channels in massive MIMO wireless cellular systems. In order to conserve resources, the proposed algorithm requires the uplink pilot signal only once, at the start of communication. By utilizing the temporal correlation between consecutive Resource Blocks (RBs) and the error correction capability of turbo codes, the channel matrix in subsequent RBs is estimated at the Base Station (BS) itself using the uplink data of current the RB and the estimated channel matrix of previous the RB. Compared to existing blind estimation methods, the proposed method places fewer limitations on the system settings such as the number of BS antennas, the number of users, and the number of coherent channel usage compared to existing blind estimation methods. Simulation results show that the proposed algorithm provides better performance for a moderate RB size, a high-order of QAM scheme, and a smaller ratio of the number of BS antennas and mobile terminals (N/K). For a reasonably small N/K (order of 10), the proposed scheme achieves a lower symbol error probability than the conventional pilot-based estimation approach. Keywords: Massive MIMO, Channel estimation, Resource block, Turbo coding, Mobile terminal

Depillaring of the existing pillars (square or rectangular in shape) by continuous miner provides irregular shaped ribs. An assessment of strength of such a rib becomes a difficult task. Literature review finds a number of approaches for the rib design but the scope of straight forward application of these approaches is limited due to the uniqueness of geo-mining conditions of the Indian coalfields. This review also finds that a wide spectrum of moderate roof conditions is yet to be properly addressed. Field studies at some depillaring operations in Indian coalfields indicated the influence of roof strata over the stability of a rib is considerably high. A systematic study of the roof strata influence on simulated models provided interesting results. A model for rib design is conceived on the basis of the simulation results. Discussing couple of field experiences of rib stability during mechanised depillaring under two different types of roof strata of Indian coalfields, this paper presents some results of the simulation along with the conceived model of a rib design.

This paper exploits variations in the average channel gains in multi-cell multi-user massive multiple input multiple output (MIMO) systems. An average transmit power-control-based sum-rate optimization scheme is presented for the uplink of the system. The matched filtering (MF) and the zero forcing (ZF) processors are considered with perfect and imperfect channel state information at receiver (CSIR) under frequency flat Rayleigh fading channel. An average power-control-based system model is constructed for analyzing the sum-rate and formulating an optimization problem. A discrete level combinatorial optimization is performed for MF and ZF sum-rate under perfect and imperfect CSIR. The numerical results show a significant improvement in the sum-rate and power consumption. A low complexity algorithm for numerical optimization of the sum-rate is proposed. The performance of algorithm is quantified with different scenarios including different number of users, macro cells, and micro cells with low and high inter-cell interference powers. The evaluation results show that the improvement in sum-rate and energy efficiency increases with inter-cell interference power and the number of MTs.

Background: Several studies, as well as licensing bodies, have found that poor communication skill is the most frequent underlying cause of complaints against physicians and malpractice allegations. Objectives: The objectives of the study were to know the perception of the interns as well as the faculty about the communication Skills Training Programme. Methodology: The workshop was conducted to train the interns in communication skills. To know the effect of sensitization program; feedback, of the students and the faculty members as the assessors, was taken after the completion of the posting. Results: Most of the students and faculty agreed on the feasibility of the workshop and appreciated its contribution in medical education. In spite of the known challenges, it was found to be a great approach to ensure it as a part of the curriculum. Conclusions: The perception of the interns as well as the faculty was found to be favorable in all aspects of the introduction of communication Skills Training Programme.

Separation of skin and stringer is likely to be a failure mode in co-cured composites stiffened panels where there is considerable out-of-plane deformation. Such deformations are possible when a stiffened skin structure is loaded in compression/shear beyond buckling or in structures which contain a disbond/delamination at the skin–stringer interface. Prediction of damage initiation and progressive growth in numerical simulations require parameters such as interface fracture toughness which have to be obtained through specimen tests. Since interface toughness is generally mode dependent, this study deals with the design and testing of three different configuration of blade stiffened co-cured composite skin–stringer specimens under mode-I and mode-II dominated loading. Finite element numerical models are developed using three-dimensional cohesive elements to predict the disbond growth under mode-I and mode-II dominated loading. The work also addresses the complexities in the convergence of numerical simulations that arise due to cohesive elements. A systematic way to obtain the best values for cohesive element parameters while finding a balance between accuracy of the results, computation time and numerical stability is presented. The present cohesive element modelling and analysis methodology successfully predicted the disbond growth in skin–stringer specimen and can be used to predict disbond/delamination onset or growth in composite stiffened structures subjected to high bending.

Display Omitted Comparison of BSA and FFA for their performance in tuning AGC controller.Tuning of controllers with new objective functions from ACE signals of model.Sensitivity analysis of tuned controller for change in system parameter is computed.Statistical comparison of responses for AGC controllers tuned by BSA, FFA, PSO, GA. This paper concentrates on the validation of metaheuristic algorithms like backtracking search optimization algorithm (BSA) and fruit fly optimization algorithm (FFA) for tuning a optimal PID controller for automatic generation control. For this purpose, a two area reheat interconnected thermal system with nonlinearities like generator rate constant (GRC), deadband and time delay are considered. The proposed work is implemented using MATLAB Simulink for various load conditions with objective functions for metaheuristic algorithms capturing signals from various positions of proposed model. The results obtained using two algorithms are compared and explored.

Four water-based organic composite coating solutions were prepared and applied on galvanised sheet samples producing a transparent film of about 5-µm thickness. Their corrosion performances were examined by Tafel polarisation, EIS, salt spray and cyclic corrosion tests. The primary coating formulation contained an acrylic emulsion and polyurethane dispersion mixture together with additives. The corrosion resistance properties of the primary formulation were enhanced by adding nano-ZnO particles, and further improved by adding corrosion inhibitors such as zinc phosphate and sodium phosphate. The final formulation on galvanised samples showed 720 h of salt spray resistance and 90 cycles of cyclic corrosion resistance, SAE J2334. The Tafel and EIS studies indicate that the coating possesses barrier protection properties. The electrolyte penetrates through the coating within 24 h but progress of corrosion depends upon the coating adhesion and its compactness, that is improved significantly by adding nano-ZnO ...

Most of the latest context-based applications capture the mobility of a user using Inertial Measurement Unit (IMU) sensors like accelerometer and gyroscope which do not need explicit user-permission for application access. Although these sensors provide highly accurate mobility context information, existing studies have shown that they can lead to undesirable leakage of location information. To evade this breach of location privacy, many of the state-of-the-art studies suggest to impose stringent restrictions over the usage of IMU sensors. However, in this paper, we show that typing and smartphone engagement patterns can act as an alternative modality to sniff the mobility context of a user, even if the IMU sensors are not sampled at all. We develop an adversarial framework, named ConType, which exploits the signatures exposed by typing and smartphone engagement patterns to track the mobility of a user. Rigorous experiments with in-the-wild dataset show that ConType can track the mobility contexts with an average micro-F 1 of 0.87 (±0.09), without using IMU data. Through additional experiments, we also show that ConType can track mobility stealthily with very low power and resource footprints, thus further aggravating the risk.

The usage of mobile phones has witnessed a revolutionary shift with an increasing number of users employing it for accessing the web. Consequentially, there has been an overwhelming increase in data usage. Data is being transmitted as data, voice is sent as data, and video is also transmitted as data. The phenomenal rise in data rates has been dictated by Edholm's law of bandwidth, which is an extension of all-pervasive Moore's law. The leaps taken forward in mobile communication by the advancement of technology have been characterized by transition from one generation to other. The demand for bandwidth has increased manifold times. The conventional method of providing a dedicated channel to a user is no longer in vogue. Instead, we need to devise ways that enable smart spectrum sharing and can help ease the bandwidth crunch. In this article, the key technology drivers for the development of the Fifth Generation(5G) are illumined as envisaged by the International Telecommunications Union (ITU). The role of machine learning in the task of dynamic spectrum sensing and management is being increasingly explored. With the enhanced complexity of 5G the conventional of spectrum sensing and assignment may not suffice. Although, the supervised algorithms have improved the performance, but the unsupervised machine learning algorithms need to be augmented. Hence the role of cognitive machine learning in smart spectrum sharing is envisaged and highlighted.

Wireless relay cooperation emerges as key technology for enhancing transmission reliability, network capacity and coverage. This is a newly emerged area which has a lot of potential to support high data rate communication. Such wireless network operates in hostile environment where signal quality effected due to the presence of scatters in between communication link and they are responsible for the phenomena of shadowing and path-loss. Besides it, quality of signal also effected from multi-path fading phenomena, here constructive and destructive combining of signals occur at the receiver. It is quite challenging for the receiver to recover the original message correctly in presence of additive and multiplicative noise. Hence, for such type of network, a unified approach is required to attract researchers and resolved various unaddressed issues till now. In this paper, multi-hop decode & forward parallel relay network is studied and establish a closed form expression of outage probability for Nakagami-m channel. Nakagami-m channel, decode and forward mode, signal to noise power ratio, probability density function, outage probability.

The concept of cooperative diversity emerges as key technology for enhancing network capacity, transmission reliability and expands the coverage in wireless networks. This is a newly emerged area which has a lot of potential to support high data rate communication. Such wireless network operates in hostile environment where signal quality effected due to the presence of scatters in between communication link and they is responsible for the phenomena of shadowing and path-loss. Besides it, quality of signal also effected from multi-path fading phenomena, here constructive and destructive combining of signals occur at the receiver. It is quite challenging for the receiver to recover the original message correctly in presence of additive and multiplicative noise. Hence, for such type of network, a unified approach is required to attract researchers and resolved various unaddressed issues till now. In this paper, two-hop regenerative parallel relay network is studied and establish a closed form expression of outage probability for Nakagami-m channel. Integrity of derived expression is also crosschecked with the help of Monte Carlo simulation.

This chapter presents the application of fractional differential operator in modelling and control of a three-tank interacting level process. In cases where the usage of sensors for the measurement of primary variable, which is the level of third tank in present case, is physically or economically not feasible, the measurement of secondary variable (i.e., second tank level) is used to determine the level of third tank for control purpose, known as inferential control scheme. The process is modeled and linearized around the operating points, resulting in third order plant, which is approximated to lower order integer and non-integer model. Both conventional integer order PI (IO-PI) & PID (IO-PID) and fractional order PI (FO-PI) & (FO-PID) controllers are implemented for this inferential control. Extensive simulation studies performed using MATLAB validate the supremacy of non-integer order model and controller over integer order model and controller. Genetic algorithm (GA) is being applied for both, firstly for reduced order model approximation and secondly for controller tuning.

In this paper, we propose a new model predictive control (MPC) formulation for autonomous driving. The novelty of our MPC stems from the following results. Firstly, we adopt an alternating minimization approach wherein linear velocities and angular accelerations are alternately optimized. We show that in contrast to the joint optimization, the alternating minimization exploits the structure of the problem better, which in turn translates to reduction in computation time. Secondly, our MPC explicitly incorporates the time dependent non-linear actuator dynamics that captures the transient response of the vehicle for a given commanded velocity. This added complexity improves the predictive component of MPC resulting in improved margin of inter-vehicle distance during maneuvers like overtaking, lane-change, etc. Although, past works have also incorporated actuator dynamics within MPC, there has been very few attempts towards coupling actuator dynamics to collision avoidance constraints through the non-holonomic motion model of the vehicle and analyzing the resulting behavior. We use a high fidelity simulator to benchmark our actuator dynamics augmented MPC with other related approaches in terms of metrics like inter-vehicle distance, trajectory smoothness, and velocity overshoot.

Self-powered photodetectors have grown as inevitable members of the optoelectronic device family. However, it is still challenging to achieve self-powered photodetection with good responsivity in the visible spectrum region. Herein, we report solution-processable poly(3-hexylthiophene) (P3HT)-molybdenum disulfide (MoS2) organic-inorganic hybrid material, which can be used as the active layer in self-powered photodetectors. The morphological and structural properties of the synthesized P3HT-MoS2 hybrid material has been discussed using atomic force microscopy and transmission electron microscopy, respectively. The hybrid material loaded with 1 wt% MoS2 has shown an enhancement in the self-assembly of polymer in the form of fibrillar formation and excellent structural features in terms of π-conjugation. The self-powered photodetectors have been fabricated in indium tin oxide (ITO) coated glass/P3HT-MoS2/Al configuration. The merit of P3HT-MoS2 hybrid photodetectors is measured under the illumination of 470, 530, and 627 nm light in ambient conditions. P3HT-MoS2 photodetectors show significantly higher responsivity and detectivity. The photo responsivity and detectivity in P3HT-MoS2 devices are found to be 271.2 mA/W and 4.4 × 1010 jones at zero bias, respectively, for 470 nm light with the optical power density of 74.1 µW/cm2. Furthermore, the photocurrent switching behaviour at periodic illuminations of 1 Hz has also been examined for P3HT-MoS2 self-powered photodetectors.

The purpose of this paper is to find the effect of heat source/sink parameter on free convective flow of a polar fluid in open-ended vertical concentric annuli. Exact solutions of the non-dimensional differential equations describing the flow model have been obtained one by one for two different cases of source and sink. To observe the effect of the physical parameters such as source/sink and vertex viscosity, the numerical results of the velocity and microrotational velocity are finally shown on the graphs.

Application of roof bolts to support in developed galleries during underground coal mining is a common practice. Mechanised depillaring (MD) applies these roof bolts to support the galleries at the goaf edge also. Goaf edge of a depillaring panel inherits a number of openings, which provides least resistance path for the caving roof strata to encroach the working areas. Influence of strata caving, inside the goaf, make it difficult to apply conventional roof bolt support norms in these openings at the goaf edge. Basic rock mechanics considerations find that the mining induced stress development improves the efficacy of roof bolt at the goaf edge. Application of, relatively, high density of bolts as roof bolts-based breaker line support (RBBLS) in the existing openings at the goaf edge to arrest the goaf encroachment is found to be working satisfactorily only if the surrounding natural supports are stable. The stability of a natural support, in and around the goaf edge, is found to be diluted due to side spalling/loosening caused by the mining induced stress. Different field experiences found that a high value of the stress causes side spalling/loosening in natural supports, standing in and around the goaf edge. Under the existing geo-mining conditions of some of the recent MD operations in Indian coalfields, the extent of spalling varied from 0.5 m to 2 m only. Considering an acceptable dimension of the rib/snook for these site conditions, the position of RBBLS is shifted out-bye from the goaf line as per the extent of spalling, which performed satisfactorily in the field. Presenting basic working principles of a RBBLS at the goaf edge; this paper discusses different field experiences for a suitable positioning of the RBBLS at the goaf edge.

Tailoring the electronic properties of molybdenum disulfide (MoS2) is essential to obtain the best performance of its electronic and optoelectronic devices. Here, we report a simple methodology to improve the performance of bi-layer (BL) MoS2 field-effect transistors (FETs) by a combination of nitrogen (N2) gas and deep-ultraviolet (DUV) light treatment. Threshold voltages of BL MoS2 FETs shifted towards a negative gate voltage after treatment with N2 gas in the presence of DUV light. The charge-carrier mobility of BL MoS2 was improved significantly after exposure to N2 gas under DUV light irradiation. The carrier density of BL MoS2 was enhanced after treatment with N2 gas in the presence of DUV light. We believe that our work may also help improve the performance of other two-dimensional nanomaterials.

Atomically thin two-dimensional (2D) materials are attractive because they have excellent material properties and channel length scalability. Fabrication of complex structures from these materials is also relatively easy. Accordingly, 2D materials such as molybdenum disulfide (MoS2) have been intensively studied because of their novel properties for advanced electronics and optoelectronics. This study realizes the low-voltage and high-performance field-effect transistors with chemical vapor deposition-grown single layer graphene employed as the thinnest electrode and semiconducting multilayer (ML) MoS2 utilized as a channel material. The two-terminal mobility of graphene-contacted ML MoS2 using 15 nm Al2O3 as the top-gate dielectric layer is 131.2 cm2/(V s) at room temperature, which is higher than that of the previously reported metal/graphene-contacted MoS2. The result demonstrates that van der Waals bonding at the graphene–MoS2 interfaces and high-k dielectric provide an important step toward the reali...

We present a modular power management system that can harvest energy from three sources simultaneously, with available power levels of 25 nW to $100~\mu \text {W}$ , with one inductor. The DC-DC converter is clocked with energize and dump pulses, and the pulse-widths are generated for constant peak inductor current and for no reversal, without current sensing. We use a comparator to reach the open-circuit-voltage (OCV)-based maximum power point (MPP), and train an oscillator to mimic the comparator output. The oscillator frequency is tuned through a successive-approximation algorithm within 11 comparator cycles. The 180 nm chip has a maximum efficiency of 87% at an input available power of $20~\mu \text {W}$ (input voltage of 0.6 V), and has an output voltage of 1.5 V.

Application of wheeled mobile robots has gradually progressed from the confines of structured indoor environments to rough outdoor terrains. Material transport and exploration are some of the few areas where wheeled robots are required to navigate over uneven terrains. Stable and efficient navigation of wheeled robots over uneven terrains requires a framework which can correctly ascertain the stability and maneuverability for a given robot's state. Most existing works on uneven terrain navigation assume a one-to-one correspondence between postural stability and maneuverability. In this paper, we show that such characterization is incomplete as states having high postural stability may have restricted maneuverability depending on underlying terrain topology. We thus, present a novel metric called Feasible Acceleration Count (FAC), introduced in our earlier works as a unified measure of robot stability and maneuverability. The metric gives the measure of the space of feasible accelerations available to the robot at a given state. The feasibility is decided by a set of inequalities which depends not only on robot's state but also on surface normals at the wheel ground contact point. This unique feature of the FAC metric makes it a more appropriate choice for motion planning on uneven terrains than metrics like Tip-Over. We further show that since space of feasible accelerations is a direct characterization of the space of possible motions at a given state, the metric FAC, also quantifies the quality of state space exploration achieved at each step of incremental sampling based planners. We build on top of this aspect of FAC and present an incremental trajectory planner with a novel node selection criteria for navigation of generic four wheeled robots and articulated systems like mobile manipulators on uneven terrain. A novel dynamic stability metric called Feasible Acceleration Count (FAC) is proposed.FAC gives a measure of the space of feasible/stable accelerations at a given state.It acts as a unified metric for quantifying stability and maneuverability of robot.It quantifies the efficiency of state space exploration in sampling based planners.An incremental planner with a novel node selection criteria based on FAC is proposed.

The rate-reliability-complexity limits of a quasi-static $K$ -user multiple access channel (MAC), with or without feedback, are explored in this paper. Using high-SNR asymptotics, bounds on the computational resources required to achieve near-optimal (ML-based) decoding performance are first derived. They, in turn, yield bounds on the (reduced) complexity needed to achieve any (including suboptimal) diversity-multiplexing tradeoff (DMT) performance. Similar complexity-bounds in the presence of feedback-aided user selection are also given. This latter effort reveals the ability of a few bits of feedback not only to improve performance, but also to reduce complexity. In this context, our analysis reveals the interesting finding that a proper calibration of user selection can allow for near-optimal ML-based decoding, with complexity that need not scale exponentially in the total number of codeword bits. The derived bounds constitute the best known performance-versus-complexity behavior to date for ML-based MAC decoding, as well as a first exploration of the complexity-feedback-performance interdependencies in multiuser settings.