Showing papers by "Md. Rafiqul Islam published in 2023"
TL;DR: In this article , the impact of rain attenuation on path loss, path loss exponent (PLE), and shadow fading (SF) have been investigated for accurate signal estimation in Malaysia based on outdoor microcellular at 38GHz on a 300 m path length.
Abstract: The deployment of a millimeter wave over a short path is one of the keys to enabling technologies for the next generation of wireless communication systems. Path loss (PL) is the most important parameter to indicate the performance of the mm-wave wireless channel. However, the accuracy and efficiency of each model are limited to characterize path loss for an environment that is different in terms of weather conditions and geographical arrangement from that for which they have been designed. This paper analyzed path loss for accurate signal estimation in Malaysia based on outdoor microcellular at 38GHz on a 300 m path length. The impact of rain attenuation on path loss, path loss exponent (PLE), and shadow fading (SF) have been investigated. This paper also presents two-channel models utilized for simulations in terms of the outdoor Large-Scale Path Loss, the statistical spatial channel model NYUSIM (version 2) developed in 2019 by New York University (NYU) and the 3rd Generation Partnership Project (3GPP) TR 38.900 Release 14 channel mode. Even though the CI and 3GPP models are accurate and suitable in the area where the measurement campaign was carried out in the temperate climate and must need modification for different regions, such as tropical climate. The underestimation can be interpreted because of the difference in AF's attenuation factors (pressure, humidity, temperature, rain rate) calculated by the CI model in the NYUSIM simulations and the attenuation factor (AF) obtained from measurement data. The NYUSIM channel model better estimated the measured data of path loss compared with 3GPP. Thus, the CI model is suitable for outdoor environments.
3 citations
24 Feb 2023
TL;DR: In this article , the authors proposed a dynamic and adaptive wireless sensor network node radio configuration using the Levenberg Marquardt Artificial Neural Network (LM-ANN) self-organise network model.
Abstract: The Wireless Sensor Network needs to become a dynamic and adaptive network to conserve energy stored in the wireless sensor network node battery. This dynamic and adaptive network sometimes are called SON (Self Organizing Network). Several SON concepts have been developed such as routing, clustering, intrusion detection, and other. Although several SON concepts already exist, however, there is no concept for SON in dynamic radio configuration. Therefore, the authors’ contribution to this field would be proposing a dynamic and adaptive Wireless Sensor Network node radio configuration. The significance of their work lies in the modelling of the SON network that builds based on our measurement in the real-world jungle environment. The authors propose input parameters such as SNR, the distance between the transmitter and receiver, and frequency as the static parameter. For adaptive parameters, we propose bandwidth, spreading factor, and its most important parameter such as power for data transmission. Using the Levenberg Marquardt Artificial Neural Network (LM-ANN) self-organise Network model, power reduction and optimisation from 20 dBm to 14.9 dBm for SNR 3, to 11.5 dBm for SNR 6, and to 12.9 dBm for SNR 9 all within a 100-m range can be achieved. With this result, the authors conclude that we can use LM-ANN for the wireless sensor network SON model in the jungle environment.
3 citations
TL;DR: Wang et al. as mentioned in this paper examined the impact of data imbalance on developing an effective SCADA-based IDS, which used convolutional neural networks coupled with long short-term memory (CNN-LSTM).
Abstract: Integrating IoT devices in SCADA systems has provided efficient and improved data collection and transmission technologies. This enhancement comes with significant security challenges, exposing traditionally isolated systems to the public internet. Effective and highly reliable security devices, such as intrusion detection system (IDSs) and intrusion prevention systems (IPS), are critical. Countless studies used deep learning algorithms to design an efficient IDS; however, the fundamental issue of imbalanced datasets was not fully addressed. In our research, we examined the impact of data imbalance on developing an effective SCADA-based IDS. To investigate the impact of various data balancing techniques, we chose two unbalanced datasets, the Morris power dataset, and CICIDS2017 dataset, including random sampling, one-sided selection (OSS), near-miss, SMOTE, and ADASYN. For binary classification, convolutional neural networks were coupled with long short-term memory (CNN-LSTM). The system’s effectiveness was determined by the confusion matrix, which includes evaluation metrics, such as accuracy, precision, detection rate, and F1-score. Four experiments on the two datasets demonstrate the impact of the data imbalance. This research aims to help security researchers in understanding imbalanced datasets and their impact on DL SCADA-IDS.
2 citations
TL;DR: In this article , the authors proposed a Patient-Centered Blockchain-Based EHR Management (PCEHRM) system that allows patients to manage their healthcare records across multiple stakeholders and to facilitate patient privacy and control without the need for a centralized infrastructure by means of granting or revoking access or viewing one's records.
Abstract: Accessing healthcare services by several stakeholders for diagnosis and treatment has become quite prevalent owing to the improvement in the industry and high levels of patient mobility. Due to the confidentiality and high sensitivity of electronic healthcare records (EHR), the majority of EHR data sharing is still conducted via fax or mail because of the lack of systematic infrastructure support for secure and reliable health data transfer, delaying the process of patient care. As a result, it is critically essential to provide a framework that allows for the efficient exchange and storage of large amounts of medical data in a secure setting. The objective of this research is to develop a Patient-Centered Blockchain-Based EHR Management (PCEHRM) system that allows patients to manage their healthcare records across multiple stakeholders and to facilitate patient privacy and control without the need for a centralized infrastructure by means of granting or revoking access or viewing one’s records. We used an Ethereum blockchain and IPFS (inter-planetary file system) to store records because of its advantage of being distributed and ensuring the immutability of records and allowing for the decentralized storage of medical metadata, such as medical reports. To achieve secure a distributed, and trustworthy access control policy, we proposed an Ethereum smart contract termed the patient-centric access control protocol. We demonstrate how the PCEHRM system design enables stakeholders such as patients, labs, researchers, etc., to obtain patient-centric data in a distributed and secure manner and integrate utilizing a web-based interface for the patient and all users to initiate the EHR sharing transactions. Finally, we tested the proposed framework in the Windows environment by compiling a smart contract prototype using Truffle and deploy on Ethereum using Web3. The proposed system was evaluated in terms of the projected medical data storage costs for the IPFS on blockchain, and the execution time for a different number of peers and document sizes. The findings of the study indicate that the proposed strategy is both efficient and practicable.
1 citations
TL;DR: In this paper , the authors estimate the genetic trends for grain yield of rice varieties released between 1970 and 2020 by the Bangladesh Rice Research Institute. But, the results suggest that limited progress has been made in improving yield in Bangladeshi rice breeding programs over the last 50 years.
Abstract: Abstract To assess the efficiency of genetic improvement programs, it is essential to assess the genetic trend in long-term data. The present study estimates the genetic trends for grain yield of rice varieties released between 1970 and 2020 by the Bangladesh Rice Research Institute. The yield of the varieties was assessed from 2001–2002 to 2020–2021 in multi-locations trials. In such a series of trials, yield may increase over time due to (i) genetic improvement (genetic trend) and (ii) improved management or favorable climate change (agronomic/non-genetic trend). In both the winter and monsoon seasons, we observed positive genetic and non-genetic trends. The annual genetic trend for grain yield in both winter and monsoon rice varieties was 0.01 t ha −1 , while the non-genetic trend for both seasons was 0.02 t ha −1 , corresponding to yearly genetic gains of 0.28% and 0.18% in winter and monsoon seasons, respectively. The overall percentage yield change from 1970 until 2020 for winter rice was 40.96%, of which 13.91% was genetic trend and 27.05% was non-genetic. For the monsoon season, the overall percentage change from 1973 until 2020 was 38.39%, of which genetic and non-genetic increases were 8.36% and 30.03%, respectively. Overall, the contribution of non-genetic trend is larger than genetic trend both for winter and monsoon seasons. These results suggest that limited progress has been made in improving yield in Bangladeshi rice breeding programs over the last 50 years. Breeding programs need to be modernized to deliver sufficient genetic gains in the future to sustain Bangladeshi food security.
1 citations
TL;DR: In this paper , a two-stage mixed-model approach accounting for experimental design factors and pedigrees was adopted to obtain the breeding values for yield and estimate genetic trends under the salinity conditions.
Abstract: Genetic gain is a crucial parameter to check the breeding program’s success and help optimize future breeding strategies for enhanced genetic gains. In this work, IRRI’s historical data from the Philippines and Bangladesh of the salinity breeding program was used to estimate the genetic gains and identify the best lines based on higher breeding values for yield as a future genetic resource. Two-stage mixed-model approach accounting for experimental design factors and pedigrees was adopted to obtain the breeding values for yield and estimate genetic trends under the salinity conditions. A positive genetic trend of 0.1% per annum with a yield advantage of 1.52 kg/ha for the Philippines and 0.31% per annum with a yield advantage of 14.02 kg/ha for Bangladesh datasets was observed. For the released varieties, genetic gain was 0.12% per annum with a yield advantage of 2.2 kg/ha/year and 0.14% per annum with a yield advantage of 5.9 kg/ha/year, respectively. Further, based on higher breeding values for grain yield, a core set of the top 145 genotypes with higher breeding values of >2400 kg/ha in the Philippines and >3500 kg/ha in Bangladesh with a selection accuracy >0.4 were selected for formulating the elite breeding panel as a future breeding resource. Conclusively, higher genetic gains are pivotal in IRRI’s rice salinity breeding program, which requires a holistic breeding approach with a major paradigm shift in breeding strategies to enhance genetic gains. Key Message Estimating genetic gains and formulating a future salinity elite breeding panel for rice pave the way for developing better high-yielding salinity tolerant lines with enhanced genetic gains.
TL;DR: In this article , a trial was conducted to evaluate the growth promoting effect of foliage applied gibberellic acid (GA3) at various spraying frequencies for mungbean crop.
Abstract: Optimizing the dose and foliar application frequency of growth regulators such as gibberellic acid (GA3) may play an important role in ensuring food security under changing climate scenarios by boosting grain yield of food legumes such as mungbean. A trial was conducted to evaluate the growth promoting effect of foliage applied gibberellic acid (GA3) at various spraying frequencies for mungbean crop. The employed treatments included four gibberellic acid levels (0, 100, 200, and 300 ppm) and two application frequencies (single spray at 30 days after sowing DAS, and two sprays at 30 and 40 DAS). Water relations, yield contributing characteristics and mungbean grain yield were among the response variables investigated. The research findings revealed that GA3 (200 ppm applied twice at pre-flowering and post-flowering stages) significantly improved the water relations, morphological and yield attributes of mungbean. This treatment combination remained unmatched by producing the highest relative water content in the stem (85.52), water retention capacity in the stem (17.24), and water uptake capacity in the stem and leaf (2.35). Furthermore, the same treatment combination resulted in the maximum plant height (50.04 cm), pods per plant (11.07), pod length (6.62 cm), grains number per pod (11.00), 100-grains weight (3.78 g), grain yield per plant (4.57 g), and a minimum water saturation deficit. Thus, GA3 foliage application at 200 ppm at 30 and 60 DAS has the potential to stimulate growth and increase the yield attributes and grain yield of mungbean. However, additional in-depth field trials with various doses of GA3 sprayed at a higher frequency may be required before recommending GA3 for general adoption to mungbean growers.
23 Feb 2023
TL;DR: In this paper , the impact of recessed gate metal on the performance of double-gate junctionless MOSFETs considering GaAs as channel material was studied. And the results of various figure of merits (FOMs) show that GaAs-based recessed-gate DG-JLMOSFets are extremely viable for the advancement of the upcoming nano-technology.
Abstract: The impact of recessed gate metal on the performance of double-gate junctionless MOSFET (DG-JLMOSFET) has been studied considering GaAs as channel material. The geometry of the gate metal is changed to obtain the best performance by recessing it to gate oxide for 1 nm vertically and extending it up to 9 nm horizontally on both sides. Changing the gate's geometrical shape and physical dimension, the leakage current is found to be reduced significantly for a fixed channel length of 10 nm. This results in a higher ION/IoFF ratio of ~ 1010 which in turn mitigates the drain induced barrier lowering (DIBL). The calculated results on various short channel effects (SCEs) indicate that the proposed model seems to have a greater drain current and a decreased subthreshold swing (SS) of 71 mV/Dec. The results of various figure of merits (FOMs) show that GaAs-based recessed gate DG-JLMOSFETs are extremely viable for the advancement of the upcoming nano-technology.
TL;DR: In this article , the first-principles calculation of the 2D layered nanostructure of SnGe2N4 is presented for photocatalysis applications, which has a direct bandgap of 1.73 eV/2.64
Abstract: Recently, semiconductor photocatalysts for green hydrogen (H2) fuel require two-dimensional (2D) material with semiconducting direct bandgap and enhanced visible light absorptions. In this study, the first-principles calculation of the 2D layered nanostructure of SnGe2N4 is presented for photocatalysis applications, which has a direct bandgap of 1.73 eV/2.64 eV (Perdew–Burke–Ernzerhof/Heyd–Scuseria–Ernzerhof with generalized gradient approximation) with enhanced optical absorptions. The structure is checked to confirm the chemical formidability and dynamical steadiness by formation energy calculations and phonon dispersions. To attain the tunability of electronic and optical properties, biaxial strains, together with tensile and compressive strains, are incorporated, and it is found that compressive strain widens the bandgap, whereas tensile strain causes bandgap reduction. Biaxial strains also improve the optical absorption and the highest absorption coefficient is obtained at ∼1.47 ⨯ 105 cm−1 for 6% compressive strain, comparable to conventional perovskite materials. However, in the visible spectrum, the highest absorption coefficient is obtained for 6% tensile strain. The calculated photocatalytic band edges suggest that this material has sufficient kinetic overpotential for photo redox at compressive strains in both pH = 7 and pH = 0. In addition, the spatial carrier separation is achieved due to having a large intralayer effective potential deviation of ∼6.96 eV, as well as intralayer spatial atomic group contribution in the valance band maximum and conduction band minimum. Conclusively, the analysis in this study can be a theoretical background of this layered nanostructure as a potent photocatalyst for water splitting.
27 Jan 2023
TL;DR: In this article , a double gate junction-less field effect transistor (DGJLFET) was proposed to optimize improved electrical characteristics with channel length variation, including threshold voltage rolloff, ON to OFF current ratio, Drain Induced Barrier Lowering (DIBL), and Sub-threshold swing (SS).
Abstract: This paper reports recessed GaAs-based double gate junction-less field effect transistor (DGJLFET) for achieving improved performance that includes threshold voltage roll-off, ON to OFF current ratio, Drain Induced Barrier Lowering (DIBL), and Sub-threshold swing (SS). The proposed device aims to optimize improved electrical characteristics with channel length variation. With regard to the channel of 10 nm, recessed GaA$s$ DGJLFET shows an $\mathbf{I}_{\text{ON}}/\mathbf{I}_{\text{OFF}}$ value of $8.21\times 10^{11}$, SS of 70 mV/dee, and DIBL of 57 $\mathbf{m}\mathbf{VV}^{-1}$, For further modification of its electrical behavior, the operation of the suggested device with regard to the variation in the length of the recessed GaAs channel could be a great target. The projected recessed GaAs DGJLFET has been modeled using the 2D SILVACO TCAD tool.
TL;DR: In this paper , the authors planned a field experiment, which was conducted at the Regional Agricultural Research Station, Ishwardi, Pabna during 2016-2017 and 2017-2018 to find out the most suitable way of relaying mukhikachu (MU) with hybrid maize to get the maximum benefit.
Abstract: Relay cropping is a method that increases total productivity through maximum utilization of resources. In this study, we planned a field experiment, which was conducted at the Regional Agricultural Research Station, Ishwardi, Pabna during 2016-2017 and 2017-2018 to find out the most suitable way of relaying mukhikachu (MU) with hybrid maize to get the maximum benefit. Seven treatments: T1= Relay at silking stage (100 DAS), T2 = Relay at the blister stage (110 DAS), T3 = Relay at the milk stage (120 DAS), T4 = Relay at the dough stage (130 DAS), T5 = Relay at the dent stage (140 DAS), T6 = Sole hybrid maize, T7 = Sole mukhikachu, were compared in the study. It was found that among the treatments (relay cropping and sole stand), there was no significant difference in terms of yield and attributes of both base (maize) and relay crop (mukhikachu). In the entire treatment, maize yielded 10.54-11.30 t ha-1 with results of 3.28-3.66 MJ m-2day-1 light energy interception (120 DAS), 2.68-2.84 LAI (120 DAS) and 1534.63-1592.69 g m-2 TDM (140DAS). The mukhikachu yielded 26.88-27.28 t ha-1 among the relay cropping system. Maize equivalent yield (MEY) and BCR ranged from 28.48-29.18 t ha-1 and 2.33-2.39, respectively, amongst the relay cropping treatments. The land equivalent ratio (LER) of the relay cropping treatment produced almost double (1.934-1.996) that of the sole crops. Farmers can benefit by adopting this relay cropping technology when they grow long-duration crops, and this technology can lead to improved system productivity.
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Abstract: Citation
TL;DR: In this article , the authors proposed a new model for the rain rate with and without the time delay considering the three variables of rain rate, time delay and frequency, which can be reliably used for future earth-to-satellite link designs by using measured rain rate at any higher frequencies.
Abstract: The propagation impairments by rain strongly affect the earth-to-satellite links operating at frequencies higher than 18 GHz mainly due to the severe performance degradation of satellite communication system. The time diversity technique with appropriate time delay between successive transmissions has been found effective in mitigating the rain fade. However, time diversity analysis demands measured rain attenuation data, where the latter is unavailable at most of the places to be able to design future high frequency links. The time diversity gain prediction model has been found to be robust for time diversity improvement. Here, we propose a new model for the rain rate with and without the time delay considering the three variables of rain rate, time delay and frequency. The rain rate and time delay functions were first used to derive the constants by the regression from the rain rate and rain rate gain. The constant for the frequency function was then extracted from the cumulative distribution function of the attenuation predicted by the analytically obtained ITU-R and gain equations. The proposed model was validated using one-year rain rate and attenuation data measured at two different locations in Malaysia demonstrating a 7% prediction inaccuracy when compared to the existing models, therefore, it can be reliably used for future earth-to-satellite link designs by using measured rain rate at any higher frequencies.
Journal Article•
TL;DR: In this paper , a cross-sectional observational study was conducted in the department of cardiology in Mymensingh Medical College Hospital from October 2017 to March 2019 to evaluate the prognostic implications of serum magnesium level in patients with acute myocardial infarction.
Abstract: Acute myocardial infarction (AMI) patients characterize a large proportion of admissions in coronary care unit and their management and risk stratification is of immense importance. Hypomagnesemia is a long-term risk factor for incident of both myocardial infarction and arrhythmia. We assessed whether serum magnesium levels at admission is associated with arrhythmias and in-hospital mortality in patients with acute myocardial infarction (AMI). The aim of the study was to evaluate the prognostic implications of serum magnesium level in patients with acute myocardial infarction. This cross-sectional observational study was conducted in the department of cardiology in Mymensingh Medical College Hospital from October 2017 to March 2019. Total 259 acute myocardial infarction patients were included considering inclusion and exclusion criteria. The sample population was divided into two groups: Group-I: Patients with acute myocardial infarction with serum magnesium ≥1.82mg/dl. Group-II: Patients with acute myocardial infarction with serum magnesium <1.82mg/dl. Serum magnesium level was measured on admission, and the incidence of in-hospital major cardiac events was assessed. In this study mean serum magnesium level of Group-I, Group-II were 2.21±0.14mg/dl, 1.60±0.15mg/dl respectively. It was statistically significant (p<0.05). In-hospital outcomes of the study group revealed that low risk group patients were uneventful outcome during hospitalization period, they had no any complication. In Group-I patient, 9(4.8%) were developed arrhythmias, 26(13.9%) were developed heart failure, 9(4.8%) were developed cardiogenic shock and 3(1.6%) were died and in Group-II patient, 44(61.10%) developed arrhythmias, 9(12.50%) were developed heart failure, 7(9.7%) were developed cardiogenic shock and 12(16.7%) were died out of them which was statistically significant (p<0.05). Mean duration of hospital stay of the study population according serum magnesium level was in Group-I, 4.27±0.68 days, in Group-II, 5.84±1.05 days which was statistically significant (p<0.05). In conclusion patient with serum magnesium level less than 1.82mg/dl increased the risk of in-hospital arrhythmia and death.
TL;DR: In this paper , a 2-year study was conducted where germination potential was evaluated in the first year and carried out in petri dish culture of seeds, followed by plastic pot culture for plant establishment and bulb development evaluation during the second year.
Abstract: Abiotic stress, especially salt stress, is one of the major barriers to crop production worldwide. Crops like onion that belong to the glycophytic group are more sensitive to salinity stress. A huge study regarding the influence of salinity stress on the growth and development of crops has already been done and is still ongoing. One of the major targets of the research is to develop genotypes that have enhanced performance under stress environments. The world needs more of these types of genotypes to combat the ever-growing salt-stressed soils. Therefore, a number of germplasm were studied during the 2019–2020 and 2020–2021 seasons under different salt concentrations to identify tolerant genotypes as well as to study the plants’ responses at different growth stages against elevated salinity levels. A 2-year study was conducted where germination potential was evaluated in the first year and carried out in petri dish culture of seeds, followed by plastic pot culture for plant establishment and bulb development evaluation during the second year. Four different saline water solutions having different salt concentrations (0, 8, 10, and 12 dS m−1) were applied to the petri dishes and pots as the source of water for plants in both seasons. Results indicated that a significant reduction in plants’ performance occurs under higher salinity levels. Salt concentration had an adverse impact on germination, leaf development and growth, the height of plants, bulb size and shape, and the bulb weight of onion. All the growth phases of onion are sensitive to elevated concentrations. Variable performances were observed in the genotypes under stress conditions, and a few genotypes (Ac Bog 409, Ac Bog 414, Ac Bog 424, Ac Bog 430, Ac Bog 417, Ac Bog 419, Ac Bog 420, Ac Bog 422, and Ac Bog 425) having some sort of tolerance to salt stress were identified, which might be recommended for mass production. Tolerance indices could successfully be applied in selecting the salt-tolerant genotypes. Thus, the present findings and the identified genotypes could be further utilized in salt stress improvement research on onion.
TL;DR: In this paper , the authors investigated the morphologic and morphometric adaptations in the lymphoid organs as well as the mortality rate in broilers in response to long-term treatment with dexamethasone (DEX).
Abstract: Abstract Background Thymus, bursa of Fabricius and spleen are the major lymphoid organs of avian species that plays a crucial role in their immunity. Though glucocorticoids are reportedly used as growth promoters, they also suppress the immune system. Objectives The objective of this study was to investigate the morphologic and morphometric adaptations in the lymphoid organs as well as the mortality rate in broilers in response to long‐term treatment with dexamethasone (DEX). Methods A total of 80 one‐day‐old broiler chicks (Cobb 500) were randomly divided into four homogenous groups (control – C and treatment groups – T1, T2, and T3). The treatment groups received DEX at the rate of 3, 5, and 7 mg/kg commercial feed. Samples, i.e. thymus, bursa of Fabricius, and spleen, were collected on 7, 14, 21, and 28 days of the experiment. Relative weight of the organs was calculated on each sampling day. The tissues were then processed and stained with haematoxylin and eosin stain for morphological and morphometric study. Results The relative weight of lymphoid organs was found substantially (p < 0.05) less in the DEX‐treated groups. Significant (p < 0.05) reduction in lobular size and the cortical‐medullary ratio was observed in the thymus of the DEX‐treated broilers. Follicular atrophy and massive depletion of lymphocytes were evident in the bursa of Fabricius. The mortality rate was also increased which was largely dependent on the dose and duration of DEX treatment. Conclusions The study results indicate that DEX treatment can alter the morphology and morphometry of lymphoid organs which might result in severe immunosuppression and increased mortality rate in broilers.
TL;DR: In this article , an Event-Horizon (EH) algorithm is proposed to afford heterogeneous downstream services from different service providers for IEEE PONs [Ethernet PON (EPON) and 10 gigabit EPON (10G EPON)].
Abstract: A multi-optical line terminal (multi-OLT) passive optical network (PON) is gaining attention for its multi-access, wide coverage, and integration capabilities. It outperforms conventional single OLT PON, reducing operational complexities, packet delay, and loss. A novel multi-OLT PON-based open-access network (OAN) architecture is proposed that integrates various service providers (SPs) as well as different access networks. Optical network unit structure is also designed to support differential access. The challenging issue here is to incorporate heterogeneous SPs and provoke downstream service with their application diversity. This paper presents what we believe is a novel algorithm named Event-Horizon (EH) to afford heterogeneous downstream services from different SPs for IEEE PONs [Ethernet PON (EPON) and 10 gigabit EPON (10G EPON)]. It incites SP competitiveness and ensures a user experience of seamless migration from service to service. Downstream resource allocation is an atypical issue in the PON area. There are reported numerous online schemes with prediction for the upstream side. Since network data is highly bursty and unpredictable, the EH algorithm uses the machine-learning-based bootstrapping method as its prediction tool. The algorithm improves downstream performance by four distinctive features. First, bandwidth is guaranteed among shared SPs according to service level agreements. Second, bandwidth is allocated for reported data; then excess bandwidth is reallocated as predicted (by bootstrapping) differed data. Third, a donor SP preserves margin before excess bandwidth release, which is a nonlinear process featuring network dynamics. Fourth, the margin satisfaction factor is formulated for tuning multi-service user satisfaction according to quality of service. The simulation is performed by a model OAN showing an emergency medical wireless sensor network (WSN) as the master shareholder OLT and a fiber to the home (FTTH) as a subsidiary one. Performance tuning on the margin reservation of 1% for the WSN case study shows 99.4% network efficiency with maximum jitter of 50 µs up to the full load owing 97.26% throughput. Network delay justifies CISCO and ITU-T requirements for real-time IP traffic. FTTH experiences the packet loss of 0.68% using the EH algorithm at the full load, maintaining WSN emergency service packet ${\rm loss} \lt {0.003}\%$.
TL;DR: In this article , the detailed optical and electronic characteristics of 2D GeC and 2D PtO2 under biaxial strains and electric fields across the plane are studied systematically using the density functional theory (DFT) based first-principles framework.
Abstract: The detailed optical and electronic characteristics of 2D GeC and 2D PtO2 under biaxial strains and electric fields across the plane are studied systematically using the density functional theory (DFT) based first-principles framework. The six different stacking patterns of the stacked van der Waals (vdW) GeC/PtO2 hetero-bilayers were DFT screened, and HBL 4 and HBL 5 are found both dynamically stable and energetically favorable, evident from the non-zero phonon frequency and negative binding energy from phonon dispersion and binding energy calculations, respectively. The bandgap of 2D GeC and 2D PtO2 is found to be ∼2.08 eV (direct) and ∼1.63 eV (indirect), while the bandgaps in vdW HBL 4 (HBL 5) are found to be 0.51 eV (0.49 eV). Biaxial strain lowered the bandgap by ∼11.13 (∼1.81) times at 6% compressive (tensile) biaxial strain in HBL 4 (HBL 5). Semiconductor-to-metal switching is found in both HBLs at ±0.6 V/Å of the cross-plane electric field. All the HBLs show type-II band-alignment, evident from the difference in charge density and projected density of state contour, indicating spatial carrier separation capability. The peak of the optical absorption coefficient is found to be ∼3.1 × 105 cm−1 at 310 nm for both HBL 4 and HBL 5, which is comparable to high-absorbing perovskite material. Moreover, the optical absorption is sensitive to the biaxial strains and electric fields, and increased visible band optical absorption is found for tensile strains in both HBLs. These exceptional findings and engineered bandgap in GeC/PtO2 vdW HBL indicate the promising application of this material in 2D advanced nanoelectronics.