Showing papers by "Md. Rafiqul Islam published in 2019"

Smartphone aided real-time blood vein detection system

Abstract: This paper aims to develop a real-time integrated system for the detection of the blood vein utilizing an Android Mobile App. The system is intended to be a low cost solution for medical teams at clinics, emergency rooms and hosptials. The system reduces the enjuries incurred due to inaccuracies during the process of frequent needle injection when blood vein is not visible during patient’s skin inspection. Illuminated infrared light in the blood cells of the vein is absorbed due to the manifestation of the Haemoglobin in blood and the IR non-blocking camera can capture the vein patterns in the IR light spectrum. Contrast Limited Adaptive Histogram Equalization (CLAHE) algorithm was used to enhance the pattern of the vein in the Android application developed using OpenCV3. Developed system can detect the veins up to 7mm underneath of human skin in real time with a frame rate of 25fps. This is a far better improvement than commercial systems that can detect veins only below 10mm underneath the skin. Moreover, this system not only focused on needle infusion but also it can be used to indicate the place of bleeding for the clots from the human body strokes, etc. in the upper layer of skin. It can also be used to detect & measure liquids in encapsulated in confined dark bottles, for example, liquid chemical pouring into the bottles in the chemical companies, liquid medicine pouring to bottles, etc. The system can be further developed to detect skin infection and other dermatological diseases underneath the skin.

Continuous Power Flow Analysis for Micro-Generation Integration at Low Voltage Grid

Abstract: The integration of micro-generation (μG) in distribution networks faces new challenges concerning the technical as well as commercial management. The μG integration in the Low and medium voltage distribution networks has many advantages for the grid operation, such as voltage profiles improvement, power losses reduction, and branches congestion levels reduction. This paper presents a method for guiding continuation power flow simulation of integrating μG on distribution feeders. A base model is designed with variable capacitor bank, μG unit such as PV and Wind generation are integrated. A control method is used to improve the voltage level of each node as well as improving power factor of the systems. The electricity consumption of a university's substation area where commercial, residential and municipal load are presented are modeled using actual data collected from each single residential hall and commercial buildings. This model allows analyzing the power flow and voltage profile along each distribution feeders on continuing fashion for a 24- hour period at hour-by-hour formulation. By dividing the feeder into load zones based on distance from each load node to distribution feeder head, the impact of integration of different μG operation in different condition has been discussed.

Performance Analysis of Perovskite Solar Cells with Different Structures

Abstract: Perovskite solar cells (PSCs) have recently emerged as a promising candidate for photovoltaic technology because of their potential low cost with considerable power conversion efficiency. In this paper, the performance of PCSs is investigated using a physics based analytical model considering important parameters. Two basic structures (i.e., p-i-n and n-i-p) of PSC are considered for this work to find out the optimal design parameters. The changes of the short circuit current density, open circuit voltage, efficiency along with the J-V characteristics curves for both structures of PSCs are shown here as performance indicating parameters. This analysis would help to understand the basic physical parameters responsible for increasing the efficiency of PSCs and find out their optimal design parameters.

Analysis of different digital filters for received signal strength indicator

Abstract: Due to high demand in Internet of Things applications, researchers are exploring deeper alternative methods to provide efficiency in terms of application, energy, and cost among other factors. A frequently used technique is the Received Signal Strength Indicator value for different Internet of Things applications. It is imperative to investigate the digital signal filter for the Received Signal Strength Indicator readings to interpret it into more reliable data. A contrasting analysis of three different types of digital filters is presented in this paper, namely: Simple Moving Average filter, Alpha Trimmed Mean filter and Kalman filter. There are three criteria used to observe the performance of these digital filters which are noise reduction, data proximity and delays. Based on the criteria, the choice of digital signal processing filter can be determined in accordance with its implementations in [ractice. For example, Alpha-Trimmed Meanfilter is shown to be more efficient if used in the pre-processing of Received Signal Strength Indicator readings for physical intrusion detection due to its high data proximity. Hence, this paper illustrates the possibilities of the use of Received Signal Strength Indicator in different Internet of Things applications given a proper choice of digital signal processing filter.

Evaluation of Performance Outcomes of Medical Equipment Technology Management and Patient Safety: Skilled Clinical Engineer’s Approach

Abstract: With the rapid development of medical equipment technology, the quality of patient care becomes under the spotlight of clinical engineering management of medical equipment since the past 4 decades and it is continually. Researchers give in-depth attention to minimize undesired incidents which are associated with medical and surgical equipment such as patients' unnatural deaths and injuries. This proposed research work investigates the relationship between performance outcomes of medical equipment technology management/patient-care technology and the reduction in undesired events like injury and even unnatural deaths. This proposed research work investigates the effect of varying levels of performance on quality of patient care and uses an indicator such as patient safety (PS) and cost-effective care by applying mathematical modeling of clinical engineering approach methodology to medical equipment technology management. In this study the quality model of Clinical Engineering Departments is determined by educational qualification, Clinical Engineering (CE) certification, training, and duration of experiences in this field. The standard performance of patient-care technology management is determined by the parameters of medical devices and the outcomes performance of medical equipment is determined. Data for this study was collected from 18 countries including from high, upper and lower-middle income regions. We were able to collect and analyze data of different performance levels of CE and biomedical engineering programs. The analysts' report measures the performance outcomes of Medical Equipment Technology Management System (METMS) and its impact on patient-care outcomes specifically impact on the reduction of patient risk factors associated with medical and surgical equipment. The findings should encourage researchers and healthcare stakeholders to better integrate the clinical engineering professionals in a hospital in order to achieve a safe functional condition of medical equipment to keep its scheduled life span in compliance with recommended span declared by manufactures. Cost-effective Clinical Engineering Department (CED) model can be designed and monitored through the methodology of this study. We hope that this study will motivate the deployment of senescence methodology for conventional electro-medical assets, by biomedical engineering and medical professionals, healthcare policymakers, equipment users, and vendors to improve outcomes as proposed by the research work described in this paper.

Accelerometer Based Structural Health Monitoring System on the Go: Developing Monitoring Systems with NI LabVIEW

Abstract: Structural Health Monitoring (SHM) is a very crucial part of maintenance and management of buildings and structures. The use of SHM in recent years has been increasing due to the advancement in technology and the availability of nanodevices and nanosensors which can detect damaged part or crack in a structure. In this paper, PSpice simulation was carried out to show the response of the integrated electronic piezoelectric (IEPE) with a VPWL-source. Then, practical experiment was done using Arduino Mega with the ADXL335 accelerometer in a laboratory setup. LabVIEW software was used along with Arduino IDE software to make graphical visualization of accelerometer reading to be captured. Furthermore, a web service was deployed which enabled LabVIEW data transmission to a smartphone running Data Dashboard application for real-time monitoring anywhere. Therefore, making the system an ecosystem of Internet of Things enabling the user to access monitoring system while on the move. The result of the vibration test on the accelerometer showed that the accelerometer response to small changes in the x, y and z axis of the accelerometer which can be used to detect micro-movements in a structure.

Designing large-scale antenna array using sub-array

Abstract: Antenna array of large scale have been examined for different applications including 5G technology. To get better data rate or a reliable link substantial number of antenna arrays have been utilized to provide high multiplexing gains as well as array gains with high directivity. In this paper a simple but efficient implementation technique of using sub-arrays for the improvement of large-sized uniform arrays. By repeating a small sub-array multiple times large arrays can be designed. This implication of utilizing small array simplifies the design of a larger array which allows the designer to concentrate on the smaller sub-array before assembling larger arrays. So, by investigating the sub arrays the performance and radiation characteristics of large arrays can be anticipated. The array-factor for a planar sub-array of 2x2 (4 elements) is analyzed using Mat-lab software and then a large array is formed by pl acing the 2x2 sub-array indifferent configurations in a rectangular arrangements up to 8x8 planar array. A nd then the results are validated with CST (Computer simulation technology) simulation results .In this way the array-factors, directivities, HPBWs, and side lobes of the constructed large arrays are analyzed and associated with the small sub-array.

Performance Comparison of SMDG and DMDG XOI FET: An Analytical Study

Abstract: In this paper, the performance of dual material double-gate (DMDG) III-V-on-insulator field effect transistor (XOI FET) is studied using an analytical compact model developed by solving 2D Poisson equation. Based on the model, the surface potential, electric field, threshold voltage, DIBL, and drain current profile are estimated for DMDG structure and compared with that of single material double-gate (SMDG) structure. The steeper change in surface potential profile at the gate materials interface demonstrates better suppression of short channel effects in case of DMDG structure than SMDG structure. The reduction of peak electric field as a function of gate materials work function difference indicates that the impact of hot electron effects can be controlled for DMDG structure with respect to SMDG structure. The results of threshold voltage, drain induced barrier lowering (DIBL), and drain current suggest that the DMDG device structure outperforms compared to conventional SMDG device structure.

Performance of MWSAC-OCDMA Considering the Effects of Fiber FWM and Dispersion

Abstract: In this paper the performance of multiwavelength spectral amplitude coding optical code division multiple access (MWSAC-OCDMA) is studied considering the combined influence of fiber four wave mixing (FWM) and dispersion loss (DL) (i.e. loss of received signal power due to chip shape broadening) using modified quadratic congruence code as address sequence. The signal to noise ratio of the proposed system is analyzed on accounts of different receiver noises contributed by balanced receiver as well as optical beating interference and multiple access interference. The power penalty suffered by the system is calculated at bit error rate 10- $\pmb{9}$ as a function of different system parameters in the presence and absence of FWM and DL. Although the system performance improves remarkably compensating the influence of FWM using fiber having higher dispersion coefficient, it degrades due to the incremental effect of DL with increasing dispersion coefficient. The results obtained here demonstrated that there is tradeoff between FWM compensation and DL in MWSAC-OCDMA system.

Performance of BER with different diversity techniques for millimeter-wave communication system

Abstract: In a communications system, a diversity technique is used to enhance the reliability of a message signal by using at least two channels with different characteristics. In this paper, all four possible scenarios are considered: Single-input and singleoutput (SISO), single input and multi-output (SIMO), multipleinput and single-output (MISO), Multiple-input and multiple output (MIMO) systems. Antenna arrays will be used to reduce BER and improve the performance of the system using array gain in the line of sight channel for 60 GHz frequency in an indoor scenario. Single input and single output are investigated before analysis of multiple inputs and multiple output channel in the line of sight (LOS) and multipath propagation. MATLAB simulation has been performed using BPSK modulation. The comparative studies show that the performance of the MIMO diversity technique is more reliable in terms of BER to improve the performance and efficiency of the communication system.

Subthreshold Characteristics of DMDG XOI FinFET

Abstract: Double gate (DG) MOSFETs are one of the most indispensable devices in semiconductor industry. But, with scaling short-channel effects (SCEs) become very much problematic for the proper operation of the devices in subnanometer regime. To alleviate these SCEs, underlap dual-material (DM) DG III-Von insulator FinFET is proposed here. This structure offers the advantages of an underlap concept along with the merits of using compound semiconductor materials in the channel. Here two-dimensional Poisson's equation is solved to develop the mathematical models of surface potential and subthreshold current of the device. To ensure faster logic operations Ino.3Gao.7Sb is used in the channel. The results of the proposed device structure are evaluated in terms of surface potential, subthreshold current, subthreshold swing, drain-induced barrier lowering, and I on /I Off ratio. It is observed that, the gate underlap length as well as gate metals work-function difference have strong impact on the reduction of subthreshold current and surface potential profile, and hence on suppression of SCEs of the device.

Performance of Short Channel Junctionless Cylindrical Surrounding Gate Si- and III-V-Based MOSFETs: A Comparative Study

Abstract: In this paper, a comparative study is presented between the performance of short channel junctionless cylindrical surrounding gate (SCJCSG) Si- and InGaSb-based MOSFETs in the subthreshold regime with source/drain depletion effect solving 2D Poisson's equation on account of parabolic approximation and symmetry condition. The different figure of merits like central potential, subthreshold current, threshold voltage, subthreshold slope, and drain-induced barrier lowering is estimated by altering the channel materials (Si and InGaSb) of the device and then compared as a function of length, radius, oxide thickness, doping concentration, and metal work-function. The results obtained from the present study demonstrate that the SCJCSG device structure works well for suppressing short-channel effects in the nanoscale regime due to better electrostatic control of the gate over the channel. Further, III-V material-based device shows better results compared to the Si-based device with a view to faster logic operation.

Comparative Study on the Performance of 3D DMTG and SMTG III-VON MOSFETs

Abstract: Here a comparative study is presented on the performances of 3D dual-material triple-gate (DMTG) and single-material triple-gate (SMTG) III-V semiconductors-on-nothing (III-VON) MOSFETs. Different figures of merits of the devices such as surface potential, electric field, threshold voltage, threshold voltage roll-off, subthreshold swing (SS), and drain induced barrier lowering (DIBL) are investigated solving 3D Poisson's equation. The step-like behavior in the surface potential at the gate-metal interface facilitates to decouple the source and channel regions from the drain region for DMTG device structure. Physical parameters (gate length ratio L 1 : L 2 , width w, and thickness, z) dependent performance of both devices are also studied. Moreover, three gates with two different gate materials offer better gate control, reduced DIBL, and a threshold voltage roll-off of the device. So, DMTG structure shows better immunity against different short channel effects (SCEs) compared to SMTG structure and could be a suitable candidate for high-speed logic applications.

Effect of the electron blocking layer in dual-wavelength emission of InGaN/GaN MQW light-emitting diodes

Abstract: ‘III-nitride’ semiconductor based light emitting diodes (LEDs) have completely transformed the lighting industry due to its unique optical and electrical properties, which leads to higher efficiency and brightness. However, electron leakages, poor hole injection, and efficiency droop significantly affect the electrical and optical properties of InGaN/GaN LEDs that leads to the poor power conversion efficiency. These problems can be effectively minimized by introducing an Electron Blocking Layer (EBL) in conventional LEDs. The objective of this work is to investigate the effect of EBL layer (i.e., Al x Ga l-x N) on dual wavelength InGaN/GaN LEDs with different Al compositions (x). Different compositions of AlxGal-xN have been used to study the electrical and optical properties of LEDs and find out their optimal design parameters by using APSYS simulation program. The simulation results suggested that the composition of Al of the EBL and properties of quantum well has significant effects on the optical and electrical properties of InGaN/GaN LEDs. The gradually increasing composition (from $x$ = 0 to 0.13) of the EBL shows large output power from the LED as it significantly reduces the electrons leakages of the device.

Study of Ohmic Contact on p-InGaN Using MIGS Model

Abstract: The formation of ohmic contact to p-InGaN has been analyzed here using the Metal induced Gap States (MIGS) model with an ultrathin interfacial layer of insulator. The position of Fermi level and barrier height modulation has been investigated for two different combinations of Metal-Insulator with p-InGaN. In case of p-InGaN with 2nm layer of NiO, Au formed a barrier height of 0.49 eV. The contact resistivity for $\mathbf{Au}/\mathbf{NiO}(\pmb{2}\ \mathbf{nm})/\mathbf{p-}\mathbf{In}_{\pmb{0.48}}\mathbf{Ga}_{\pmb{0.52}}\mathbf{N}$ is found to be $\pmb{2.35\times 10^{-4} \Omega-}\mathbf{cm}^{\pmb{2}}$ at 300K and $\pmb{1.15\times 10^{-4} \Omega-}\mathbf{cm}^{\pmb{2}}$ at 600K. It is also observed that the metal with higher work function gives lower barrier height and contact resistivity in case of p-InGaN. For Pt/AI 2 O 3 (2 nm)/p-In 0.48 Ga 0.52 N, the barrier height becomes 0.312 eV and the contact resistivity is estimated as $\pmb{1.9\times 10^{-4}\Omega-} \mathbf{cm}^{\pmb{2}}$ at 300K and $\pmb{0.75\times 10^{-4}\Omega-}\mathbf{cm}^{\pmb{2}}$ at 600K. Thus, Pt contact shows better performance than Au contact to p-InGaN. This information of MIS contact could be a good insight for conventional CMOS in case of source/drain applications.

Channel layer-dependent optimization of on-state current and subthreshold swing of MoS 2 TFET

Abstract: This paper presents a comparative analysis among two different layers (monolayer and multilayer) of molybdenum disulfide (MoS 2 ) channel based n-type tunnel field-effect transistor (TFET) to optimize on-state current and subthreshold swing ( $S_{th} S$ ) by tuning different device parameters such as oxide thickness, doping concentration, screening length, dielectric strength as a function of gate voltage and electric field. Two closed-form analytical models of tunneling current and ${S_{th}} S$ are used for MoS 2 -based TFET due to the superior performance of MoS 2 as a channel material for post-silicon and beyond-graphene technology. Additionally, band-to-band tunneling (BTBT) mechanism results in higher on-state current and lower $S_{th} S$ in TFETs compared to MOSFETs. The present study reveals that it's quite hard to get the best-optimized results for the on-state current and $S_{th} S$ simultaneously, that is, there is a tradeoff between them. The whole optimization process is carried out by varying two parameters and variables concurrently in order to have more accurate results.