scholarly journals Simulation Model for Blockchain Systems Using Queuing Theory

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 234 ◽  
Author(s):  
Raheel Memon ◽  
Jian Li ◽  
Junaid Ahmed
Keyword(s):  
Internet Of Things ◽  
Performance Measures ◽  
Waiting Time ◽  
Queuing Theory ◽  
Smart Home ◽  
System Throughput ◽  
Block System ◽  
Proposed Model ◽  
Wide Range ◽  
Good Agreement

In recent years, blockchains have obtained so much attention from researchers, engineers, and institutions; and the implementation of blockchains has started to revive a large number of applications ranging from e-finance, e-healthcare, smart home, Internet of Things, social security, logistics and so forth. In the literature on blockchains, it is found that most articles focused on their engineering implementation, while little attention has been devoted to the exploration of theoretical aspects of the system; however, the existing work is limited to model the mining process only. In this paper, a queuing theory-based model is proposed for understanding the working and theoretical aspects of the blockchain. We validate our proposed model using the actual statistics of two popular cryptocurrencies, Bitcoin and Ethereum, by running simulations for two months of transactions. The obtained performance measures parameters such as the Number of Transactions per block, Mining Time of Each Block, System Throughput, Memorypool count, Waiting Time in Memorypool, Number of Unconfirmed Transactions in the Whole System, Total Number of Transactions, and Number of Generated Blocks; these values are compared with actual statistics. It was found that the results gained from our proposed model are in good agreement with actual statistics. Although the simulation in this paper presents the modeling of blockchain-based cryptocurrencies only, the proposed model can be used to represent a wide range of blockchain-based systems.

VLE Determination of Carbon Dioxide Loaded Aqueous Alkanolamine Mixtures Using Modified Kent Eisenberg Model

2017 ◽  
Vol 231 (11-12) ◽  
Author(s):  
Humbul Suleman ◽  
Abdulhalim Shah Maulud ◽  
Zakaria Man
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Model Parameters ◽  
Thermodynamic Models ◽  
Carbon Dioxide Absorption ◽  
Proposed Model ◽  
Wide Range ◽  
Experimental Values ◽  
Good Agreement

AbstractA computationally simple thermodynamic framework has been presented to correlate the vapour-liquid equilibria of carbon dioxide absorption in five representative types of alkanolamine mixtures. The proposed model is an extension of modified Kent Eisenberg model for the carbon dioxide loaded aqueous alkanolamine mixtures. The model parameters are regressed on a large experimental data pool of carbon dioxide solubility in aqueous alkanolamine mixtures. The model is applicable to a wide range of temperature (298–393 K), pressure (0.1–6000 kPa) and alkanolamine concentration (0.3–5 M). The correlated results are compared to the experimental values and found to be in good agreement with the average deviations ranging between 6% and 20%. The model results are comparable to other thermodynamic models.

scholarly journals Accurate Circuit-Level Modelling of IGBTs with Thermal Phenomena Taken into Account

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2372
Author(s):  
Paweł Górecki ◽  
Krzysztof Górecki ◽  
Janusz Zarębski
Keyword(s):  
Integrated Circuit ◽  
Bipolar Transistors ◽  
Classical Literature ◽  
Insulated Gate Bipolar Transistors ◽  
Spice Simulation ◽  
Proposed Model ◽  
Wide Range ◽  
Thermal Phenomena ◽  
Parameter Values ◽  
Good Agreement

This paper proposes a new compact electrothermal model of the Insulated Gate Bipolar Transistors (IGBT) dedicated for SPICE (Simulation Program with Integrated Circuit Emphasis). This model makes it possible to compute the non-isothermal DC characteristics of the considered transistor and the waveforms of terminal voltages and currents of the investigated device and its internal temperature at transients. This model takes into account the nonlinearity of thermal phenomena in this device. The form of the formulated model is described and the problem of estimating its parameter values is discussed. The correctness of the proposed model was verified experimentally both at DC operation and at transients. The obtained results are compared to the results of computations performed with the use of the classical literature model. A very good agreement between the results of measurements and computations performed with the new model is obtained at different cooling conditions and in a wide range of changes of parameters characterising the electrical excitation of the tested device.

scholarly journals Providing a Model for the Optimal Allocation of Hospital Beds Based on Markov Chain Approach (Case Study: Shiraz-Shahid-Faghihi Hospital)

2021 ◽  
Author(s):  
Mehdi Kabiri Naeini ◽  
Zeynab Elahi ◽  
Abolfazl Moghimi Esfandabadi
Keyword(s):  
Markov Chain ◽  
Waiting Time ◽  
Queuing Theory ◽  
Optimal Allocation ◽  
Referral Rate ◽  
Service Rate ◽  
Model Parameters ◽  
Markov Chain Approach ◽  
Proposed Model ◽  
Hospital Beds

Background: As was observed in the corona crisis, in situations, such as war or natural disasters or epidemic diseases, the intensity of the applicants for medical services causes congestion problems. In this situation, due to the limited capacity of the system, queuing phenomenon for service applicants and in some cases, rejection of clients occur. Reducing the length of hospital stays by improving performance productivity can compensate for the shortage of hospital beds. In order to increase the productivity of personnel and equipment, it is necessary to eliminate unemployment and improve service scheduling. One of the ways to achieve these goals is to optimize the distribution of beds between wards. In the present study, in the form of Markov chain approach, according to the referral rate and service rate, the existing beds were allocated to different wards of the hospital to maximize service and minimize rejection of patients. Methods: The present study is an applied study conducted in 2019 for the optimal distribution of beds between the 3 wards of Shahid Faghihi Hospital in Shiraz. The research problem was modeled in the form of Markov chain approach and assuming the referral of clients according to the continuous-time Markov chain, the model parameters value was identified. The obtained mathematical model was solved by GAMS 24.1.3 software. Results: The proposed model led to an improvement in ward performance in terms of reducing patient waiting time and increasing the number of admitted patients. The proposed model reduced patient rejection by 8.6 %. According to the patients' referral rate to the wards and the service rate of each ward, based on sensitivity analysis, the number of beds allocated to each of the 3 wards was determined. Conclusion: Queuing theory can be applied as a tool to analyze the phenomena of the treatment system and determine the features of the waiting time, queue length, and capacity of the system. Appropriate allocation of hospital beds results in improving the efficiency and decreasing the patient rejection. Therefore, it could be useful in crisis, congestion in patients, and when increasing facilities is required.

One-Dimensional Nonlinear Parametric Instability of Inhomogeneous Plasma: Time Domain Problem

2021 ◽  
Vol 24 (3) ◽  
pp. 272-279
Author(s):  
N. V. Gerasimenko ◽  
F. M. Trukhachev ◽  
E. Z. Gusakov ◽  
L. V. Simonchik ◽  
A. V. Tomov
Keyword(s):  
Initial Conditions ◽  
Inhomogeneous Plasma ◽  
Parametric Instability ◽  
Analytical Models ◽  
Dimensional Model ◽  
One Dimensional ◽  
Proposed Model ◽  
Wide Range ◽  
Spatial And Temporal Characteristics ◽  
Good Agreement

A numerical one-dimensional model of convective parametric instability of inhomogeneous plasma is developed. By using this model, a numerical solution describing spatial and temporal characteristics of interacting waves is obtained. The results obtained are in a good agreement with known analytical models and substantially generalize them. In particular, an important advantage of the proposed model is the possibility of varying initial conditions, analyzing behavior of the system in the presence of incident wave fluctuations that is important for the future study of the absolute instability mode. The model is also provides possibility to simulate absolute parametric instability with a wide range of controllable parameters, as well as to study interacting wave transients.

scholarly journals IoT Based Home Security

2020 ◽  
Author(s):  
Jinal Bakhai ◽  
Annie Eapen ◽  
Aishwarya Rao ◽  
Nidhishree Mendon ◽  
Dr.Vijaya Padmanabha
Keyword(s):  
Internet Of Things ◽  
Real World ◽  
Smart Home ◽  
The Internet ◽  
Rapid Rate ◽  
Home Security ◽  
Proposed Model ◽  
New Ideas ◽  
Home Technology ◽  
Smart Home Technology

Internet of Things (IoT) allows real-world objects to be connected and managed through the internet. IoT is used to make any device smart and is thus a booming concept worldwide. Being a part of the era of the internet, it has become easier to experiment and develop new ideas. Many such ideas have been implemented, changing people’s lifestyles in general. Smart home technology is known to bring about more comfort and convenience at our homes. We have decided to stretch this concept out further to implement the concept of IoT into the security of our homes. The proposed model focuses on the security and ease of allowing access to the house. The leverage obtained by choosing this over other forms of home security is the ease of allowing access and monitoring our homes at any time and from anywhere. Our overall system is also focused on being made at a budget so that all sections of the society can experience this convenience and safety. In a world where technology is advancing at such a rapid rate, it is to be seen that everyone plays a part and stays up to date.

scholarly journals Modified Numerical Modeling of Axially Loaded Concrete-Filled Steel Circular-Tube Columns

2021 ◽  
Vol 11 (3) ◽  
pp. 7094-7099
Author(s):  
P. C. Nguyen ◽  
D. D. Pham ◽  
T. T. Tran ◽  
T. Nghia-Nguyen
Keyword(s):  
Circular Tube ◽  
Experimental Tests ◽  
Element Model ◽  
Modified Model ◽  
Proposed Model ◽  
Wide Range ◽  
Strain Relationship ◽  
Concrete Damaged Plasticity ◽  
Cfst Columns ◽  
Good Agreement

Predicting the behavior of concrete in a Concrete-Filled Steel Tubular (CFST) column is challenging due to the sensitivity to input parameters such as the size of the cross-section, the material modeling, and the boundary conditions. The present paper proposes a new modified finite element model to predict the behavior and strength of a CFST subjected to axial compression. The development is based on the concrete damaged plasticity model, with its stress-strain relationship revised from the available model. The predicted accuracy of the modified model is verified via a wide range of experimental tests. The proposed model has more accuracy than the available models in predicting the ultimate compression strength. The results show good agreement with the test data, allowing its use in modeling CFST columns.

scholarly journals Numerical solutions of fuzzy equal width models via generalized fuzzy fractional derivative operators

2021 ◽  
Vol 7 (2) ◽  
pp. 2695-2728
Author(s):  
Rehana Ashraf ◽  
◽  
Saima Rashid ◽  
Fahd Jarad ◽  
Ali Althobaiti ◽  
...  
Keyword(s):  
Numerical Solutions ◽  
Initial Conditions ◽  
Transform Method ◽  
Homotopy Perturbation ◽  
Proposed Model ◽  
Wide Range ◽  
Fractional Models ◽  
The Subject ◽  
Good Agreement ◽  
Numerical Approaches

<abstract><p>The Shehu homotopy perturbation transform method (SHPTM) via fuzziness, which combines the homotopy perturbation method and the Shehu transform, is the subject of this article. With the assistance of fuzzy fractional Caputo and Atangana-Baleanu derivatives operators, the proposed methodology is designed to illustrate the reliability by finding fuzzy fractional equal width (EW), modified equal width (MEW) and variants of modified equal width (VMEW) models with fuzzy initial conditions (ICs). In cold plasma, the proposed model is vital for generating hydro-magnetic waves. We investigated SHPTM's potential to investigate fractional nonlinear systems and demonstrated its superiority over other numerical approaches that are accessible. Another significant aspect of this research is to look at two significant fuzzy fractional models with differing nonlinearities considering fuzzy set theory. Evaluating various implementations verifies the method's impact, capabilities, and practicality. The level impacts of the parameter $ \hbar $ and fractional order are graphically and quantitatively presented, demonstrating good agreement between the fuzzy approximate upper and lower bound solutions. The findings are numerically examined to crisp solutions and those produced by other approaches, demonstrating that the proposed method is a handy and astonishingly efficient instrument for solving a wide range of physics and engineering problems.</p></abstract>

Experimental Results and Modeling of the Codiffusion of Donors and Acceptors in Si

1995 ◽  
Vol 389 ◽  
Author(s):  
S. Solmi ◽  
S. Valmorri
Keyword(s):  
Ion Pairing ◽  
Experimental Results ◽  
Standard Process ◽  
Model Based ◽  
Proposed Model ◽  
Donor And Acceptor ◽  
Wide Range ◽  
High Concentrations ◽  
Process Simulator ◽  
Good Agreement

ABSTRACTA model based on ion pairing for the simulation of donor and acceptor codiffusion in silicon is presented. The proposed model allows us to obtain a good agreement with the experimental profiles over a wide range of diffusion conditions, specially at high concentrations where the standard process simulator codes give results strongly inaccurate. Comparison of the simulations with new and literature codiffusion profiles is provided.

CLOUD BASED INTERNET OF THINGS FOR SMART CONNECTED OBJECTS

2019 ◽  
Vol 01 (02) ◽  
pp. 31-39 ◽  
Author(s):  
Duraipandian M. ◽  
Vinothkanna R.
Keyword(s):  
Energy Consumption ◽  
Internet Of Things ◽  
Smart Home ◽  
Electricity Consumption ◽  
Considerable Improvement ◽  
The Internet ◽  
The Internet Of Things ◽  
At Home

The paper proposing the cloud based internet of things for the smart connected objects, concentrates on developing a smart home utilizing the internet of things, by providing the embedded labeling for all the tangible things at home and enabling them to be connected through the internet. The smart home proposed in the paper concentrates on the steps in reducing the electricity consumption of the appliances at the home by converting them into the smart connected objects using the cloud based internet of things and also concentrates on protecting the house from the theft and the robbery. The proposed smart home by turning the ordinary tangible objects into the smart connected objects shows considerable improvement in the energy consumption and the security provision.

scholarly journals Separate Universe calibration of the dependence of halo bias on cosmic web anisotropy

2020 ◽  
Vol 499 (3) ◽  
pp. 4418-4431 ◽  
Author(s):  
Sujatha Ramakrishnan ◽  
Aseem Paranjape
Keyword(s):  
Dark Matter ◽  
High Precision ◽  
Gaussian Distribution ◽  
Initial Perturbation ◽  
Analytical Framework ◽  
Web Environment ◽  
Wide Range ◽  
Galaxy Assembly ◽  
Very High ◽  
Good Agreement

ABSTRACT We use the Separate Universe technique to calibrate the dependence of linear and quadratic halo bias b1 and b2 on the local cosmic web environment of dark matter haloes. We do this by measuring the response of halo abundances at fixed mass and cosmic web tidal anisotropy α to an infinite wavelength initial perturbation. We augment our measurements with an analytical framework developed in earlier work that exploits the near-lognormal shape of the distribution of α and results in very high precision calibrations. We present convenient fitting functions for the dependence of b1 and b2 on α over a wide range of halo mass for redshifts 0 ≤ z ≤ 1. Our calibration of b2(α) is the first demonstration to date of the dependence of non-linear bias on the local web environment. Motivated by previous results that showed that α is the primary indicator of halo assembly bias for a number of halo properties beyond halo mass, we then extend our analytical framework to accommodate the dependence of b1 and b2 on any such secondary property that has, or can be monotonically transformed to have, a Gaussian distribution. We demonstrate this technique for the specific case of halo concentration, finding good agreement with previous results. Our calibrations will be useful for a variety of halo model analyses focusing on galaxy assembly bias, as well as analytical forecasts of the potential for using α as a segregating variable in multitracer analyses.

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