Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 58021 - 58050 of 302421

Full-Text Articles in Physical Sciences and Mathematics

Determinant Formulas Of Some Hessenberg Matrices With Jacobsthal Entries, Taras Goy, Mark Shattuck Jun 2021

Determinant Formulas Of Some Hessenberg Matrices With Jacobsthal Entries, Taras Goy, Mark Shattuck

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we evaluate determinants of several families of Hessenberg matrices having various subsequences of the Jacobsthal sequence as their nonzero entries. These identities may be written equivalently as formulas for certain linearly recurrent sequences expressed in terms of sums of products of Jacobsthal numbers with multinomial coefficients. Among the sequences that arise in this way include the Mersenne, Lucas and Jacobsthal-Lucas numbers as well as the squares of the Jacobsthal and Mersenne sequences. These results are extended to Hessenberg determinants involving sequences that are derived from two general families of linear second-order recurrences. Finally, combinatorial proofs are provided …


Nonparametric Relative Error Estimation Via Functional Regressor By The K Nearest Neighbors Smoothing Under Truncation Random Data, Wahiba Bouabsa Jun 2021

Nonparametric Relative Error Estimation Via Functional Regressor By The K Nearest Neighbors Smoothing Under Truncation Random Data, Wahiba Bouabsa

Applications and Applied Mathematics: An International Journal (AAM)

The relation between a functional random covariate and a scalar answer due to left truncation by a different random variable is evaluated in this study with the kNN method. In particular, in order to produce a nonparametric kNN regression operator of these functional truncated data as a loss function, we should use mean squared relative error. In number of neighbors, we establish an estimator and assess the uniform consistency performance with the convergence rate. Then, for different levels of computational truncated data, a simulation analysis was carried out on finite-sized samples to show the feasibility of our estimation procedure and …


Maximum Difference Extreme Difference Method For Finding The Initial Basic Feasible Solution Of Transportation Problems, Ridwan Raheem Lekan, Lord Clifford Kavi, Nancy Ann Neudauer Jun 2021

Maximum Difference Extreme Difference Method For Finding The Initial Basic Feasible Solution Of Transportation Problems, Ridwan Raheem Lekan, Lord Clifford Kavi, Nancy Ann Neudauer

Applications and Applied Mathematics: An International Journal (AAM)

A Transportation Problem can be modeled using Linear Programming to determine the best transportation schedule that will minimize the transportation cost. Solving a transportation problem requires finding the Initial Basic Feasible Solution (IBFS) before obtaining the optimal solution. We propose a new method for finding the IBFS called the Maximum Difference Extreme Difference Method (MDEDM) which yields an optimal or close to the optimal solution. We also investigate the computational time complexity of MDEDM, and show that it is O(mn).


A High Order Finite Difference Method To Solve The Steady State Navier-Stokes Equations, Nihal J. Siriwardana, Saroj P. Pradhan Jun 2021

A High Order Finite Difference Method To Solve The Steady State Navier-Stokes Equations, Nihal J. Siriwardana, Saroj P. Pradhan

Applications and Applied Mathematics: An International Journal (AAM)

In this article, we develop a fourth order finite difference method to solve the system of steady state Navier-Stokes equations and apply it to the benchmark problem known as the square cavity flow problem. The numerical results of 𝑢-velocity components and 𝑣-velocity components obtained at the center of the cavity are compared with the results obtained by the method developed by Greenspan and Casulli to solve the time dependent system of Navier-Stokes equations. The method described in this article is easy to implement and it has been shown to be more efficient and stable than the method by Greenspan and …


Hybrid Algorithm For Singularly Perturbed Delay Parabolic Partial Differential Equations, Imiru T. Daba, Gemechis F. Duressa Jun 2021

Hybrid Algorithm For Singularly Perturbed Delay Parabolic Partial Differential Equations, Imiru T. Daba, Gemechis F. Duressa

Applications and Applied Mathematics: An International Journal (AAM)

This study aims at constructing a numerical scheme for solving singularly perturbed parabolic delay differential equations. Taylor’s series expansion is applied to approximate the shift term. The obtained result is approximated by using the implicit Euler method in the temporal discretization on a uniform step size with the hybrid numerical scheme consisting of the midpoint upwind method in the outer layer region and the cubic spline method in the inner layer region on a piecewise uniform Shishkin mesh in the spatial discretization. The constructed scheme is an ε−uniformly convergent accuracy of order one. Some test examples are considered to testify …


Adaptive Hybrid Projective Synchronization Of Hyper-Chaotic Systems, Ayub Khan, Harindri Chaudhary Jun 2021

Adaptive Hybrid Projective Synchronization Of Hyper-Chaotic Systems, Ayub Khan, Harindri Chaudhary

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we design a procedure to investigate the hybrid projective synchronization (HPS) technique among two identical hyper-chaotic systems. An adaptive control method (ACM) is pro- posed which is based on Lyapunov stability theory (LST). The considered technique globally determines the asymptotical stability and establishes identification of parameter simultaneously via HPS approach. Additionally, numerical simulations are carried out for visualizing the effectiveness and feasibility of discussed scheme by using MATLAB.


Casson Fluid Flow Past On Vertical Cylinder In The Presence Of Chemical Reaction And Magnetic Field, Gaurav Kumar, S.M.K. Rizvi Jun 2021

Casson Fluid Flow Past On Vertical Cylinder In The Presence Of Chemical Reaction And Magnetic Field, Gaurav Kumar, S.M.K. Rizvi

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we have examined the behavior of unsteady flow of a viscous, incompressible and electrically conducting Casson fluid past an impulsively started vertical cylinder with variable temperature and mass diffusion in the presence of transversely applied uniform magnetic field and chemical reaction. The temperature and concentration level near the surface increase linearly with time. The governing equations of non-dimensional form of flow model have been solved numerically by using Crank-Nicolson implicit finite difference method. The velocity profile is discussed with the help of graphs drawn for different parameters like Casson fluid parameter, Prandtl number, chemical reaction parameter and …


Variation Iteration Method For Solving Ethanol And Acetaldehyde Concentrations In A Fixed Bed Laboratory Reactor, K. M. Dharmalingam, M. Veeramuni, Hadi Rezazadeh, Cemil Tunç Jun 2021

Variation Iteration Method For Solving Ethanol And Acetaldehyde Concentrations In A Fixed Bed Laboratory Reactor, K. M. Dharmalingam, M. Veeramuni, Hadi Rezazadeh, Cemil Tunç

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we investigate the effects of nonlinear behaviour of the dimensionless concentrations of the ethanol and acetaldehyde in a fixed bed laboratory reactor. The work is based on solving the nonlinear differential equation of concentration of the ethanol and acetaldehyde by means of the He’s variational iteration method (VIM). Also, the numerical simulation (4th order Runge – Kutta method) is reported using Matlab software. The analytical solutions are compared with numerical results in order to achieve conclusions based on not only for accuracy and efficiency of the solutions, but also the simplicity of the taken procedures which would …


Effect Of Magnetic And Perturbation Parameters On Blood Flow Distribution Through An Artery, Sultan Ahmad, A. F. Al-Johani, Subratakumar Sahu Jun 2021

Effect Of Magnetic And Perturbation Parameters On Blood Flow Distribution Through An Artery, Sultan Ahmad, A. F. Al-Johani, Subratakumar Sahu

Applications and Applied Mathematics: An International Journal (AAM)

The motion of the blood inside an artery is investigated under the transverse magnetic field. The velocity and temperature variation of the blood flow motion are solved by perturbation technique. We considered the magnetic field is constant and viscosity of the fluid distribution depends on temperature. We derived flow rate and wall shear stress during the flow of blood through the human artery. We analyzed the effect of temperature profiles, flow rate and wall shear stress during the propagation of blood. It is observed that the human will die with respect to the increase temperature in the blood flow distribution.


A Novel Color Image Encryption Scheme Based On Arnold’S Cat Map And 16-Byte S-Box, Tariq Shah, Ayesha Qureshi, Muhammad Usman Jun 2021

A Novel Color Image Encryption Scheme Based On Arnold’S Cat Map And 16-Byte S-Box, Tariq Shah, Ayesha Qureshi, Muhammad Usman

Applications and Applied Mathematics: An International Journal (AAM)

The presented work sets out to subsidize to the general body of knowledge in the field of cryptography application by evolving color image encryption and decryption scheme based on the amalgamation of pixel shuffling and efficient substitution. Arnold’s cat map is applied to snap off the correlation in pixels of image and the shuffled image is encrypted by 16-byte S-box substitution. Computer simulations with a standard test image and the outcome is presented to scrutinize the competence of the projected system. Several image-quality measures and security analyses have been made out for the encrypted image to estimate the statistical and …


Simplified Intuitionistic Neutrosophic Soft Set And Its Application On Diagnosing Psychological Disorder By Using Similarity Measure, Veerappan Chinnadurai, Albert Bobin Jun 2021

Simplified Intuitionistic Neutrosophic Soft Set And Its Application On Diagnosing Psychological Disorder By Using Similarity Measure, Veerappan Chinnadurai, Albert Bobin

Applications and Applied Mathematics: An International Journal (AAM)

The primary focus of this manuscript comprises three sections. Initially, we introduce the concept of a simplified intuitionistic neutrosophic soft set. We impose an intuitionistic condition between the membership values of truth and falsity such that their sum does not exceed unity. Similarly, for indeterminacy, the membership value is a real number from the closed interval [0, 1]. Hence, the sum of membership values of truth, indeterminacy, and falsity does not exceed two. We present the notion of necessity, possibility, concentration, and dilation operators and establish some of its properties. Second, we define the similarity measure between two simplified intuitionistic …


Significance Of Coriolis Force On Eyring-Powell Flow Over A Rotating Non-Uniform Surface, Abayomi S. Oke, Winifred N. Mutuku Jun 2021

Significance Of Coriolis Force On Eyring-Powell Flow Over A Rotating Non-Uniform Surface, Abayomi S. Oke, Winifred N. Mutuku

Applications and Applied Mathematics: An International Journal (AAM)

Coriolis force plays significant roles in natural phenomena such as atmospheric dynamics, weather patterns, etc. Meanwhile, to circumvent the unreliability of Newtonian law for flows involving varying speed, Eyring-Powell fluid equations are used in computational fluid dynamics. This paper unravels the significance of Coriolis force on Eyring-Powell fluid over the rotating upper horizontal surface of a paraboloid of revolution. Relevant body forces are included in the Navier-Stokes equations to model the flow of non-Newtonian Eyring-Powell fluid under the influence of Coriolis force. Using similarity transformation, the governing equations are nondimensionalized, thereby transforming the nonlinear partial differential equations to a system …


Thermal-Diffusion And Diffusion-Thermo Effects On Heat And Mass Transfer In Chemically Reacting Mhd Casson Nanofluid With Viscous Dissipation, Timothy L. Oyekunle, Mojeed T. Akolade, Samson A. Agunbiade Jun 2021

Thermal-Diffusion And Diffusion-Thermo Effects On Heat And Mass Transfer In Chemically Reacting Mhd Casson Nanofluid With Viscous Dissipation, Timothy L. Oyekunle, Mojeed T. Akolade, Samson A. Agunbiade

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we examined the combined effects of dissipation and chemical reaction in Casson nanofluid motion through a vertical porous plate subjected to the magnetic field effect placed perpendicular to the flow channel. The physical problem is modeled using partial differential equations (PDEs). These sets of PDEs, with suitable similarity transformations, are simplified into ordinary differential equations (ODEs). Collocation technique with legendary basis function is utilized in solving the transformed equations. The numerical analysis on velocity, concentration, and temperature are plotted and tabled for different flow parameters. Our findings show that by raising the Casson parameter close to infinity, …


Numerical Technique For Solving Fractional-Order Of Ivgtt Glucose-Insulin Interaction, M. A. Abdelkawy Jun 2021

Numerical Technique For Solving Fractional-Order Of Ivgtt Glucose-Insulin Interaction, M. A. Abdelkawy

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we use a numerical technique to solve fractional nonlinear differential equations systems that arise in Bergman’s minimal model that describe blood glucose and insulin metabolism, after intravenous tolerance testing. Shifted Jacobi -Gauss-Radau collocation (SJ-GR-C) method is developed for approximating the proposed model. The principal target in our technique is to transform the proposed model to a system of algebraic equations. Finally, numerical simulation is introduced to illustrate the analytical results.


Deposition And Diagenesis Of The Blossom Sand, Panola County, Texas, Hannah Chambers Jun 2021

Deposition And Diagenesis Of The Blossom Sand, Panola County, Texas, Hannah Chambers

Electronic Theses and Dissertations

The Late Cretaceous Blossom Sand within the Austin Group is a historic gas reservoir in the East Texas basin, located at depths of approximately 2,000 ft below the surface. Since the discovery of the Carthage Field in 1918 in the East Texas Basin, the Blossom Sand has produced approximately 26 BCF of gas with minor amounts of oil. Despite its notoriety in the Carthage Field, there is very little research that has been conducted on this unit, although it crops out in northeast Texas and is found in the subsurface of southwest Arkansas, western Louisiana, and the East Texas Basin. …


Tailored Porous Carbons Enabled By Persistent Micelles With Glassy Cores, Eric R. Williams, Paige L. Mcmahon, Joseph E. Reynolds Iii, Jonathan L. Snider, Vitalie Stavila, Mark Allendorf, Morgan Stefik Jun 2021

Tailored Porous Carbons Enabled By Persistent Micelles With Glassy Cores, Eric R. Williams, Paige L. Mcmahon, Joseph E. Reynolds Iii, Jonathan L. Snider, Vitalie Stavila, Mark Allendorf, Morgan Stefik

Faculty Publications

Porous nanoscale carbonaceous materials are widely employed for catalysis, separations, and electrochemical devices where device performance often relies upon specific and well-defined regular feature sizes. The use of block polymers as templates has enabled affordable and scalable production of diverse porous carbons. However, popular carbon preparations use equilibrating micelles which can change dimensions in response to the processing environment. Thus, polymer methods have not yet demonstrated carbon nanomaterials with constant average template diameter and tailored wall thickness. In contrast, persistent micelle templates (PMTs) use kinetic control to preserve constant micelle template diameters, and thus PMT has enabled constant pore diameter …


Pivot Points In Bivariate Linear Regression, David L. Farnsworth, Carl V. Lutzer Jun 2021

Pivot Points In Bivariate Linear Regression, David L. Farnsworth, Carl V. Lutzer

Articles

There are little-noticed points in the plane, which are artifacts of linear regression. The points, which are called pivot points, are the intersections of sets of regression lines. We derive the coordinates of the pivot point and explain its sources. We show how a pivot point arises in a certain notable data set, which has been analyzed often for points of high leverage. We obtain the application of pivot points that shortens calculations when updating a set of bivariate observations by adding a new point.


A Geometric Approach To Conditioning And The Search For Minimum Variance Unbiased Estimators, David L. Farnsworth, James E. Marengo Jun 2021

A Geometric Approach To Conditioning And The Search For Minimum Variance Unbiased Estimators, David L. Farnsworth, James E. Marengo

Articles

Our purpose is twofold: to present a prototypical example of the conditioning technique to obtain the best estimator of a parameter and to show that this technique resides in the structure of an inner product space. The technique uses conditioning of an unbiased estimator on a sufficient statistic. This procedure is founded upon the conditional variance formula, which leads to an inner product space and a geometric interpretation. The example clearly illustrates the dependence on the sampling methodology. These advantages show the power and centrality of this process.


Hamacher Operations Of Fermatean Fuzzy Matrices, I. Silambarasan Jun 2021

Hamacher Operations Of Fermatean Fuzzy Matrices, I. Silambarasan

Applications and Applied Mathematics: An International Journal (AAM)

The purpose of this study is to extend the Fermatean fuzzy matrices to the theory of Hamacher operations. In this paper, the concept of Hamacher operations of Fermatean fuzzy matrices are introduced and some desirable properties of these operations, such as commutativity, idempotency, and monotonicity are discussed. Further, we prove DeMorgan’s laws over complement for these operations. Furthermore, the scalar multiplication and exponentiation operations of Fermatean fuzzy matrices are constructed and their algebraic properties are investigated. Finally, some properties of necessity and possibility operators of Fermatean fuzzy matrices are proved.


Approximate 2-Dimensional Pexider Quadratic Functional Equations In Fuzzy Normed Spaces And Topological Vector Space, Mohammad A. Abolfathi, Ali Ebadian Jun 2021

Approximate 2-Dimensional Pexider Quadratic Functional Equations In Fuzzy Normed Spaces And Topological Vector Space, Mohammad A. Abolfathi, Ali Ebadian

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we prove the Hyers-Ulam stability of the 2-dimensional Pexider quadratic functional equation in fuzzy normed spaces. Moreover, we prove the Hyers-Ulam stability of this functional equation, where f, g are functions defined on an abelian group with values in a topological vector space.


Numerical Solution Of Fuzzy Fractional Differential Equation By Haar Wavelet, Sakineh Khakrangin, Tofigh Allahviranloo, Nasser Mikaeilvand, Saeid Abbasbandy Jun 2021

Numerical Solution Of Fuzzy Fractional Differential Equation By Haar Wavelet, Sakineh Khakrangin, Tofigh Allahviranloo, Nasser Mikaeilvand, Saeid Abbasbandy

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we deal with a wavelet operational method based on Haar wavelet to solve the fuzzy fractional differential equation in the Caputo derivative sense. To this end, we derive the Haar wavelet operational matrix of the fractional order integration. The given approach provides an efficient method to find the solution and its upper bond error. To complete the discussion, the convergence theorem is subsequently expressed in detail. So far, no paper has used the Harr wavelet method using generalized difference and fuzzy derivatives, and this is the first time we have done so. Finally, the presented examples reflect …


An Optimal Control Problem Solution For Chemical Reactor, Dias Nurmagambetov Jun 2021

An Optimal Control Problem Solution For Chemical Reactor, Dias Nurmagambetov

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we describe one of the solutions of a nonlinear optimal control problem for a chemical reactor. A solution on finding a chemical reactor’s optimal temperature regime for having a maximum concentration of final product is presented. The optimal control has been found by immersion method for boundary value problem with a phase and control restrictions. This method is reducing the original boundary value problem to a special optimal control problem, using the general solution of the Fredholm integral equation of the first kind. With this method's solution had been created a software for the problem calculations. Analysis …


Outcomes Of Aspheric Primaries In Robe’S Circular Restricted Three-Body Problem, Bhavneet Kaur, Shipra Chauhan, Dinesh Kumar Jun 2021

Outcomes Of Aspheric Primaries In Robe’S Circular Restricted Three-Body Problem, Bhavneet Kaur, Shipra Chauhan, Dinesh Kumar

Applications and Applied Mathematics: An International Journal (AAM)

We consider the Robe’s restricted three-body problem in which the bigger primary is assumed to be a hydrostatic equilibrium figure as an oblate spheroid filled with a homogeneous incompressible fluid, around which a circular motion is described by the second primary, that is a finite straight segment. The aim of this note is to investigate the effect of oblateness and length parameters on the motion of an infinitesimal body that lies inside the bigger primary. The locations of the equilibrium points are approximated by the series expansions and it is found that two collinear equilibrium points lying on the line …


Memory Response Of Magneto-Thermoelastic Problem Due To The Influence Of Modified Ohm’S Law, Latika C. Bawankar, Ganesh D. Kedar Jun 2021

Memory Response Of Magneto-Thermoelastic Problem Due To The Influence Of Modified Ohm’S Law, Latika C. Bawankar, Ganesh D. Kedar

Applications and Applied Mathematics: An International Journal (AAM)

In this article, in the form of the heat conduction equation with memory-dependent-derivative (MDD), a new model in magneto-thermoelasticity was developed with modified Ohm’s law. To obtain the solutions, normal mode analysis is used. The obtained solution is then exposed to time- dependent thermal shock and stress-free boundary conditions. The effect of the modified Ohm’s law coefficient, time-delay, and different kernel functions under the magnetic field effect on different quantities are evaluated and observed graphically on all field variables.


Orthogonality In Terms Of 2-Hh Norm And Bounded Linear Operators In Banach Spaces, Bhuwan P. Ojha, Prakash M. Bajracharya Jun 2021

Orthogonality In Terms Of 2-Hh Norm And Bounded Linear Operators In Banach Spaces, Bhuwan P. Ojha, Prakash M. Bajracharya

Applications and Applied Mathematics: An International Journal (AAM)

In the present paper, the generalization of the Carlson orthogonality for functionals to operators in Banach spaces has been studied. We will also investigate various properties related to the Carlsson, Birkhoff-James, and Pythagorean orthogonality for operators. Kikianty and Dragomir (2010) mentioned in their paper by stating that Pythagorean and isosceles orthogonality through the medium of 2 − HH norm satisfies the non-degeneracy, symmetry and continuity properties without mentioning detailed proof. This paper provides the complete proof of these properties as well as the equivalency of additivity and homogeneity of the isosceles orthogonality with the help of 2 − HH norm. …


Investigating The Effects Of Kyoto Protocol Mechanisms On The Environment And Economy, Erica Reanne C. Co, Samantha Colleen M. Francisco, Chelsie Marie D. Gumba, Joshua Martine J. Magallanes Jun 2021

Investigating The Effects Of Kyoto Protocol Mechanisms On The Environment And Economy, Erica Reanne C. Co, Samantha Colleen M. Francisco, Chelsie Marie D. Gumba, Joshua Martine J. Magallanes

Angelo King Institute for Economic and Business Studies (AKI)

As production processes improve, the stimulation of economic growth has overlooked its externalities over time. In pursuit of sustainable development, nations were driven to combat climate change and increasing greenhouse gas emissions through the Kyoto Protocol. The policy brief is based on the investigation of the Kyoto Protocol Mechanisms (Clean Development and Emissions Trading Scheme) through difference-in-difference (DID) estimation, together with panel regression to evaluate the path towards viability using the metrics for externalities (total greenhouse gas emissions) and economic growth (GDP). For this reason, the DID takes into account the quantitative aspect in evaluating the effectiveness of the said …


Light Regulation Of Phytoplankton Growth In San Francisco Bay Studied Using A 3d Sediment Transport Model, Zhengui Wang, Fei Chai, (...), Yinglong J. Zhang, Et Al Jun 2021

Light Regulation Of Phytoplankton Growth In San Francisco Bay Studied Using A 3d Sediment Transport Model, Zhengui Wang, Fei Chai, (...), Yinglong J. Zhang, Et Al

VIMS Articles

In San Francisco Bay (SFB), light availability is largely determined by the concentration of suspended particulate matter (SPM) in the water column. SPM exhibits substantial variation with time, depth, and location. To study how SPM influences light and phytoplankton growth, we coupled a sediment transport model with a hydrodynamic model and a biogeochemical model. The coupled models were used to simulate conditions for the year of 2011 with a focus on northern SFB. For comparison, two simulations were conducted with ecosystem processes driven by SPM concentrations supplied by the sediment transport model and by applying a constant SPM concentration of …


Nonlinearity Of Subtidal Estuarine Circulation In The Pearl River Estuary, China, Hongzhou Xu, Jian Shen, Dongxiao Wang, Lin Luo, Bo Hong Jun 2021

Nonlinearity Of Subtidal Estuarine Circulation In The Pearl River Estuary, China, Hongzhou Xu, Jian Shen, Dongxiao Wang, Lin Luo, Bo Hong

VIMS Articles

The Pearl River Estuary (PRE) is a bell-shaped estuary with a narrow deep channel and wide shoals. This unique topographic feature leads to different dynamics of the subtidal estuarine circulation (SEC) in the PRE compared with a narrow and straight estuary. In this study, the nonlinear dynamics of the SEC in the PRE under mean circumstance are analyzed by using a validated 3D numerical model. Model results show that the nonlinear advections reach leading order in the along-channel momentum balance. Modulated by tide, the nonlinear advections show significant temporal variations as they have much larger values during spring tide than …


Non-Equivocation In Blockchain: Double-Authentication-Preventing Signatures Gone Contractual, Yannan Li, Willy Susilo, Guomin Yang, Yong Yu, Tran Viet Xuan Phuong, Dongxi Liu Jun 2021

Non-Equivocation In Blockchain: Double-Authentication-Preventing Signatures Gone Contractual, Yannan Li, Willy Susilo, Guomin Yang, Yong Yu, Tran Viet Xuan Phuong, Dongxi Liu

Research Collection School Of Computing and Information Systems

Equivocation is one of the most fundamental problems that need to be solved when designing distributed protocols. Traditional methods to defeat equivocation rely on trusted hardware or particular assumptions, which may hinder their adoption in practice. The advent of blockchain and decentralized cryptocurrencies provides an auspicious breakthrough paradigm to resolve the problem above. In this paper, we propose a blockchain-based solution to address contractual equivocation, which supports user-defined fine-grained policybased equivocation. Specifically, users will be de-incentive if the statements they made breach the predefined access rules. The core of our solution is a newly introduced primitive named Policy-Authentication-Preventing Signature (PoAPS), …


Construct Validity And Invariance Assessment Of The Social Impacts Of Occupational Heat Stress Scale (Siohss) Among Ghanaian Mining Workers, Victor F. Nunfam, Ebenezer Afrifa-Yamoah, Kwadwo Adusei-Asante, Eddie J. Van Etten, Kwasi Frimpong, Isaac Adjei-Mensah, Jacques Oosthuizen Jun 2021

Construct Validity And Invariance Assessment Of The Social Impacts Of Occupational Heat Stress Scale (Siohss) Among Ghanaian Mining Workers, Victor F. Nunfam, Ebenezer Afrifa-Yamoah, Kwadwo Adusei-Asante, Eddie J. Van Etten, Kwasi Frimpong, Isaac Adjei-Mensah, Jacques Oosthuizen

Research outputs 2014 to 2021

Heat exposure studies over the last decade have shown little attention in assessing and reporting the psychometric properties of the various scales used to measure impacts of occupational heat stress on workers. A descriptive cross-sectional survey including 320 small- and large-scale mining workers was employed to assess the construct validity of the social impacts of occupational heat stress scale (SIOHSS) in the Western Region of Ghana in 2017. A confirmatory factor analysis (CFA) and invariance analysis were carried out using AMOS version 25 and statistical product and service solutions (SPSS) version 26 to examine the model fit and establish consistency …