Early detection of heart diseases using a low-cost compact ECG sensor

Multimedia Tools and Applications - Heart disease patients are continuously increasing. The patients face the problem of a delayed diagnosis as the subjects do not undergo routine tests and consult...     

Static and dynamic characteristics of short wavy journal bearings

A general analysis has been done to investigate the static and dynamic performance of short wavy journal bearing. Reynolds equation is solved for both steady‐ and unsteady‐state operations. The steady‐state analysis has been done and compared with circular bearing with respect to their load capacity, flow rate, pressure distribution and friction factor. The unsteady‐state analysis has been used to determine the rotor dynamic coefficients for various eccentricity ratios. These coefficients are used to determine the stability parameters, such as critical mass and whirl ratio, and prove that wave bearing has not only better load carrying capacity but also provides better stability at high speed than circular bearing. Copyright © 2010 John Wiley & Sons, Ltd.     

Alloying behaviour,thermal stability and phase evolution in quinary AlCoCrFeNi high entropy alloy

An equiatomic quinary AlCoCrFeNi high entropy alloy (HEA) has been synthesized by mechanical alloying. Milled powder after 30?h shows good chemical homogeneity and refined morphology with a mean particle size of ～4?μm. Solid solution phase with BCC crystal structure (a?=?2.89?±?0.02?Å) has been confirmed from XRD and transmission electron microscopy in the as-synthesized high entropy alloy. The milled alloy powder is not thermally stable. Differential scanning calorimetric (DSC) thermogram of 30?h milled powder exhibits the presence of a small peak at ～600?°C (873?K) with a thermal shift near the peak. This thermal shift indicates the diffusive type of phase transformation in this alloy while heating. The analysis of the in-situ heating X-ray diffraction patterns at various temperatures extends support to the diffusive nature of the phase transformation. Upon heat treatment, the disordered BCC solid solution phase partially transforms to Ni₃Al prototype L1₂ phase which precipitates at a lower temperature (350?°C (623?K)) as observed by in-situ XRD experiments. However, at high temperature annealing (575–800?°C (848–1073?K)) the evolution of a partially ordered BCC phase (B2) with lattice parameter (a?=?2.87?±?0.02?Å), and L1₂ phase (a?=?3.58?±?0.05?Å), along with tetragonal σ phase (a?=?8.8?Å and c?=?4.53?Å) are observed. Similar types of phases have also been identified after annealing and microwave sintering at 800?°C (1073?K) & 900?°C (1173?K) respectively. The transformation of ordered BCC phases along with two intermetallics such as L1₂ phase and σ phase suggests that the evolution of the high entropy phase in the milled condition leads to a combination of high entropy and medium entropy phases in the annealed condition.     

Laser-Induced Graphene for Electrothermally Controlled,Mechanically Guided, 3D Assembly and Human–Soft Actuators Interaction

Mechanically guided, 3D assembly has attracted broad interests, owing to its compatibility with planar fabrication techniques and applicability to a diversity of geometries and length scales. Its further development requires the capability of on-demand reversible shape reconfigurations, desirable for many emerging applications (e.g., responsive metamaterials, soft robotics). Here, the design, fabrication, and modeling of soft electrothermal actuators based on laser-induced graphene (LIG) are reported and their applications in mechanically guided 3D assembly and human–soft actuators interaction are explored. Over 20 complex 3D architectures are fabricated, including reconfigurable structures that can reshape among three distinct geometries. Also, the structures capable of maintaining 3D shapes at room temperature without the need for any actuation are realized by fabricating LIG actuators at an elevated temperature. Finite element analysis can quantitatively capture key aspects that govern electrothermally controlled shape transformations, thereby providing a reliable tool for rapid design optimization. Furthermore, their applications are explored in human–soft actuators interaction, including elastic metamaterials with human gesture-controlled bandgap behaviors and soft robotic fingers which can measure electrocardiogram from humans in an on-demand fashion. Other demonstrations include artificial muscles, which can lift masses that are about 110 times of their weights and biomimetic frog tongues which can prey insects.     

OBCD-HH: an object-based change detection approach using multi-feature non-seed-based region growing segmentation

There is an increasing need to get updated information regarding the changes on earth’s surface. The information obtained can be used in a wide range of applications including disaster management, land-use investigation etc. The high-resolution remote sensing images obtained from satellites provide us with an opportunity to detect changes on earth’s surface between various time intervals. In this paper, an unsupervised object-based change detection (OBCD) method is proposed to detect changes in high resolution bi-temporal satellite images. To detect changes, a novel multi-feature non-seed-based region growing (MF-NSRG) algorithm is proposed for image segmentation based on heterogeneity minimization that uses textural heterogeneity along with spectral and spatial heterogeneity during region growing. The performance of MF-NSRG algorithm is further improved by using Harris Hawk, a recently proposed metaheuristic algorithm, which is used to obtain optimal values of segmentation parameters. Finally, the feature maps extracted from the pre-change and post-change segmented images are analysed using histogram trend similarity (HTS) approach to detect changes. The proposed approach is known as object-based change detection using Harris Hawk (OBCD-HH). The proposed OBCD-HH approach is applied on two datasets: xBD and Onera Satellite Change Detection (OSCD) dataset. Its performance is compared with existing state-of-the-art algorithms and results show the superiority of the proposed approach.

     

Stability analysis between two concentric rotating cylinders with heat and mass transfer

The stability of the liquid/vapor interface between two concentric revolving cylinders is examined. The transfer of heat/mass is allowed at the interface. Both the cylinders rotate with different angular velocities. The fluids inside the annular region are taken as incompressible and viscous. The theory of viscous potential flow analysis is used to add the viscous effects. The normal mode technique is used to calculate the growth of perturbations. If we rotate the inner cylinder, it is seen that asymmetric disturbances have a destabilizing character at the interface but the rotation of the outer cylinder has a stabilizing effect. We found that an asymmetric disturbance destabilizes the interface if the inner cylinder rotates. It is found that the arrangement gets destabilized on rotating of the inner cylinder but rotation of the outer cylinder induces stability, and the most stable case is found when the inner cylinder is stationary and the outer cylinder is rotating.     

Swastika shaped slot embedded two port dual frequency band MIMO antenna for wireless applications

Analog Integrated Circuits and Signal Processing - A compact dual band 2?×?2 multiple-input-multiple-output (MIMO) antenna with dimension...     

Improved Configuration of Multilevel Inverter with Reduced Semiconductor Devices

In DC/AC power conversion, multi-level inverter (MLI) incorporates a large number of semiconductor devices, which increases its cost and complexity. Moreover, the recently introduced topology uses a large variety of semiconductor switches. Therefore, a great attention is paid toward increasing output voltage levels with less variety and reduced number of switches as compared to conventional topologies. In this paper, improved configuration of symmetrical and asymmetrical MLI is proposed. Improvement is brought on both quantitative and qualitative basis, which led to a reduction in number of semiconductor devices and its variety. Analysis of power losses of the proposed topology is carried out and compared with CHB. A wide range of comparison with recently proposed topologies is made in order to show the novelty and contribution of the proposed topology. Multi-Carrier Pulse Width Modulation strategy is adopted for generating the switching pulses. The detailed simulation study of the proposed topology has been carried out using MATLAB/SIMULINK and validated experimentally for 7-level and 81-level inverter.     

Compliance,network, security and the people related factors in cloud ERP implementation

Cloud enterprise resource planning (ERP) is a buzz in the information technology domain. Small and medium enterprises (SMEs) do not have the financial budget to invest in on‐premise ERP solution. The use of cloud‐based services for SMEs has led to widespread diffusion of technology. The two big stakeholders in the cloud ERP are cloud user and cloud vendor. This paper brings out the factors that are under the influence of these two stakeholders. Critical success factors that are influenced by the people in the organization are considered for the study. Compliance, network, and security are the concerns that are under the control of cloud vendor. This study shows the factors that have an impact on the successful implementation of cloud ERP. An online questionnaire was designed and data from 208 respondents belonging to SMEs were collected. Structural equation modeling was used for data analysis. It was found that people‐related factors and compliance had an impact toward the successful implementation of cloud‐based services. Network and security factors did not show any significant impact on the implementation of cloud ERP. Copyright © 2016 John Wiley & Sons, Ltd.     

Understanding knee points in bicriteria problems and their implications as preferred solution principles

A knee point is almost always a preferred trade-off solution, if it exists in a bicriteria optimization problem. In this article, an attempt is made to improve understanding of a knee point and investigate the properties of a bicriteria problem that may exhibit a knee on its Pareto-optimal front. Past studies are reviewed and a couple of new definitions are suggested. Additionally, a knee region is defined for problems in which, instead of one, a set of knee-like solutions exists. Edge-knee solutions, which behave like knee solutions but lie near one of the extremes on the Pareto-optimal front, are also introduced. It is interesting that in many problem-solving tasks, despite the existence of a number of solution methodologies, only one or a few of them are commonly used. Here, it is argued that often such common solution principles are knee solutions to a bicriteria problem formed with two conflicting goals of the underlying problem-solving task. The argument is illustrated on a number of tasks, such as regression, sorting, clustering and a number of engineering designs.