Hamming Method Research Articles

Method to Estimate Dislocation Densities from Images of α‐Ga2O3‐Based Corundum Oxides Using the Computer Vision YOLO Algorithm

This work applies the computer vision “You only look once” (YOLO) algorithm to extract bounding boxes around dislocations in weak‐beam dark‐field transmission electron microscopy (WBDF TEM) images of semiconductor thin films. A formula is derived to relate the sum of the relative heights of the bounding boxes to the dislocation densities in the films. WBDF TEM images reported in the literature and taken from our α‐Ga2O3 samples are divided into train, evaluation, and test datasets. Different models are trained using the train dataset and evaluated using the evaluation dataset to find the best confidence values, which are used to select the best model based on the performance against the test data set. For α‐Ga2O3 thin films, dislocation density output by this model is on average ≈58% of those estimated by the traditional Ham method. A factor of 4/π may contribute to the systematic underestimation of the model versus the Ham method.

Thermal analysis of viscoelastic radiative flow of tri‐hybrid nanofluid over a rotating disk using different shaped nanoparticles with applications

AbstractThe fluid containing solid nanoparticles “nanofluid” performed more effectively compared to conventional fluids. The thermal scientists and scholars considered nanofluid in their research due to its useful applications in different thermal systems. But nanofluid still not enough for the required thermal transport properties. Therefore, the researchers tried to disperse two or more than two nanoparticles which are called hybrid and tri‐hybrid nanofluid. It was tested experimentally that these hybrid nanofluids are more efficient fluids in different cooling systems compared to nanofluid and regular fluids. The present article carried out the research about the suspension of three different kinds of nanoparticles in various shapes for advance cooling applications in industries and engineering problems. The three nanoparticles are cylindrical carbon nanotubes, spherical aluminum oxide, and platelet shaped(Graphene) are mixed in water flowing in a rotating disk. This advance fluid has remarkable enhancement in the heat transfer rate in comparison with regular fluid, mono nanofluid and hybrid nanofluid. In this study viscoelastic radiative ternary hybrid nanofluid is considered on a rotating disk. The solutions are obtained by using the HAM method. For physical interpretation, all the flow parameters are discussed through graphs. The impact of volume fraction on the flow and heat transfer is also evaluated and presented in graphs. From the comparison, it was declared that tri‐hybrid nanofluid has the best thermal performance compared to hybrid and mono nanofluid. Furthermore, radiation increases the temperature of the fluid, while viscoelastic parameter decreases the radial and tangential velocity. From the present study, we noticed that by considering the tri‐hybrid mixture in water, the rate of heat transfer can be enhanced up to 33.69%. Finally, the results obtained show that the tri‐hybrid nanofluid has excellent performance in the heat transfer rate.

On a modification of the Hamming method for summing discrete Fourier series and its application to solve the problem of correction of thermographic images

The paper considers mathematical methods of correction of thermographic images (thermograms) in the form of temperature distribution on the surface of the object under study, obtained using a thermal imager. The thermogram reproduces the image of the heat-generating structures located inside the object under study. This image is transmitted with distortions, since the sources are usually removed from its surface and the temperature distribution on the surface of the object transmits the image as blurred due to the processes of thermal conductivity and heat exchange. In this paper, the continuation of the temperature function as a harmonic function from the surface deep into the object under study in order to obtain a temperature distribution function near sources is considered as a correction principle. This distribution is considered as an adjusted thermogram. The continuation is carried out on the basis of solving the Cauchy problem for the Laplace equation - an ill-posed problem. The solution is constructed using the Tikhonov regularization method. The main part of the constructed approximate solution is presented as a Fourier series by the eigenfunctions of the Laplace operator. Discretization of the problem leads to discrete Fourier series. A modification of the Hamming method for summing Fourier series and calculating their coefficients is proposed.

Analysis of second grade hybrid nanofluid flow over a stretching flat plate in the presence of activation energy

The research of fluid containing nanoparticles for the heat transport characteristics is very famous because of its variety of real-life applications in various thermal systems. Although the thermal efficiency of the nanofluid was effective but still the nano scientists were trying to introduce some new advance class of fluid. Therefore, an advance class of fluid is developed by the dispersion of two different nano sized particles in the conventional base fluid known as “Hybrid nanofluid” which is more effective compared to simple nanofluids in many engineering and industrial applications. Therefore, motivated from the hybrid type of nanofluids in the current research we have taken two-dimensional laminar and steady flow of second grade fluid passing through porous plate. The engine oil base fluid is widely used fluid in the engineering and industrial problems. Keeping these applications in mind the engine oil is considered and two different nanoparticles Copper and aluminum oxide are added in ordered to get the required thermal characteristics. In addition to this the thermal radiation, chemical reaction, activation energy, Brownian motion and thermophoresis are also addressed during the current research. The present proposed higher-order PDE’s is transformed to the non-linear system of ODE’s. For the solution of the proposed high non-linear model HAM method is employed. As the hybrid nanofluid are highlighted on the second-grade fluid flow over a horizontal porous flat plate. During the present analysis and experimental study, it has been proved that the performance of hybrid nanofluid is efficient in many situations compared to nanofluid and regular fluid. For physical interpretation all the flow parameters are discussed through graphs. The impact of volume fraction is also addressed through graphs. Moreover, the comparative analysis between hybrid and nanofluid is carried out and found that hybrid nanofluid performed well as compared to nanofluid and regular fluid. The engineering quantities obtained from the present research have been presented in tables.

Analisis Penjadwalan Proses Packing Arumanis Dengan Menggunakan Metode CDS (Campbell Dudeck Smith) dan NEH (Nawas, Enscore,and HAM) Studi Kasus di UMKM Arumanis Haji Ardi Sleman

ABSTRACT
 
 UMKM Arumanis Haji Ardi is a household industry that produces sweet arum located in Berbah, Sleman, D.I. Yogyakarta. Companies often have difficulty meeting consumer demand in a timely manner. The problem of improper delivery schedule of the order is caused by scheduling the packing process which often experiences delays. The purpose of this research is to find out the comparison of completion time, and know the methods that can complete the production process at the shortest. Campbell Dudeck Smith's scheduling method is a scheduling process based on the smallest working time, and having the advantage of being able to provide many scheduling alternatives. The Nawas, Enscore, and Ham method is that scheduling or assignments with a larger total process time should be given greater priority than the smaller total process time. Given the importance of the proper scheduling process, the author wants to do a scheduling analysis of the Packing process using the Campbell Dudeck Smith and Nawas, Enscore, and Ham methods. The results of the research comparison of scheduling time applied by the company have a sequence of 1-2-3-4 with a makepan of 44,395,142.92 seconds. Campbell Dudeck Smith was 4-3-2-1 with 44,335,921.922 seconds. Scheduling with nawas, Enscore, and Ham method has a sequence of 2-1-3-4 with makespan 44,515.921.12 seconds. The most appropriate method used is the Campbell Dudeck Smith method because it has the smallest makespan which is 44,335,921.12 seconds with a percentage of comparison between cds and NEH methods is 0.4%.
 
 Keywords: Scheduling, Packing, Campbell Dudeck Smith, Nawas, Enscore, and Ham
 

Effects of chemical reaction, viscosity, thermal conductivity, heat source, radiation/absorption, on MHD mixed convection nano-fluids flow over an unsteady stretching sheet by HAM and numerical method

Investigations are performed for further observations of heat and mass transfer in magneto-hydrodynamic mixed-convectional nano-fluid flow with the assumption of variable viscosity and thermal-conductivity over an unsteady stretching sheet. Base fluid is Carboxy-methyl cellulose (CMC) water as a carrier fluid with different nano-particles such as [Formula: see text] (Titanium), Ag (Silver), [Formula: see text] (Aluminum), and Cu (Copper). Flow contains different physical parameters, such as heat source, chemical reaction effect, Schmidt number, and radiation absorptions effects are observed to be significant in the presences of magnetic field. Obtained equations are solved by numerically BVP4C-package (shooting method) and analytically by BVPh2.0-package (Homotopy Analysis Method “HAM”). Interested physical quantities are, viscosity-parameter ( A), Thermal-conductivity parameter ( N),Thermocapillary-number ( M), Hartmann-number (Ma), Prandtl-number (Pr), 4-nano-particles ([Formula: see text]), temperature Grashof number ([Formula: see text]), and mass Grashof number ([Formula: see text]) are the focus to the velocity, temperature, and solute concentration profiles. It is concluded that, Solute concentration of ([Formula: see text])-water has higher than the other 3-nano-fluids. Mass flux, heat flux, and Skin friction of fluids are direct functions of magnetic force, while inverse function of temperature. Magnetic force also decreased the speed of fluids and hence mass flux reduced which implies that, the temperature reduces. [Formula: see text] has also inverse relation with mass flux, heat flux, and skin friction, while direct relation with the speed of fluids. Similarly, [Formula: see text] has inverse relation with [Formula: see text], [Formula: see text], and [Formula: see text], but direct relation with [Formula: see text]. Different results are shown in graphical and tabular form.

REHABILITATION OF PATIENTS WITH LONG-TERM AFTEREFFECTS OF MILD COMBAT TRAUMATIC BRAIN INJURY

The aim: To analyze the effect of Korean red ginseng on status of the vegetative nervous system and well-being of patients with asthenic syndrome assotiated with mild combat traumatic brain injury. Materials and methods: We have examined 42 patients. Duration of their injury was from 4 to 6 years. We have investigated the indices of the vegetative tonus, vegetative reactivity and vegetative provisioning, its neurally mediated component – adrenaline and noradrenaline and melatonin hormone in daily urine. Some neuropsychological data were investigated with the help of HAM method (Health, Activity and Mood scale). Results: After the treatment with Korean red ginseng all indices of the vegetative nervous system improved significantly. Accordingly, the rates of adrenaline and noradrenaline and the hormone melatonin, which were reduced before treatment in most of the examined, increased. The HAM values also improved after the treatment. Conclusions: The use of Korean red ginseng restores efficiency, sleep, activity, and improves the mood of patients with aftereffects of mild traumatic brain injury and does not cause any adverse reaction.

Minimizing Rental Costs in Flowshop Scheduling with the NEH (Nawaz, Enscor, and Ham) Method

This study discusses how to minimize rental costs in flowshop scheduling. Optimal scheduling time was obtained using the Nawaz, Enscor, and Ham (NEH) method. The right time to rent a machine is obtained by comparing the utility of the machine with the processing time of each machine with the processing time of each job on the machine. We apply this research in CV. SAMHARI which is a company that manufactures sandals. After applying the rental cost minimization method at the research site, we found that CV. SAMHARI can minimize the rental costs incurred by Rp. 273700.

Comparison Of Tests For Isomorphism In Planetary Gear Trains

There are plenty of ways available for synthesis and analysis of Planetary Gear Trains (PGTs) of one DOF. However, every method has its own shortcomings. In this paper a comparison is made between Characteristic polynomial, Eigenvalues and Eigenvectors, Hamming Number Method and Modified Path Matrix (MPM) method. There are many methods available to test isomorphism in PGTs, out of which these four methods wasanalyzed in this paper. For a given PGT with a number of links and a single Degree of Freedom (DOF), adjacency matrix is enough to find out the Eigenvalues and Eigenvectors. Isomorphism of PGT is determined using the Eigenvalues. If Eigenvalues are similar then the PGTs are isomorphic. Similarly, if the characteristic polynomials of two PGTs are samethen it represents the isomorphic PGTs. Characteristic polynomials are determined from the Adjacency matrix. Hamming method also uses adjacency matrix to generate Hamming matrix. Hamming strings are developed from Hamming Matrix. Uniform hamming strings of two PGTsindicates isomorphism in PGTs. Along with isomorphism, Symmetry also known from the Hamming method. Modified path matrix method uses a connectivity matrix to generate MPM. If train values of two PGTs are same then they will be isomorphic otherwise non isomorphic. As per literature as the number of links increases the results may not be accurate with Characteristic coefficients and Eigenvalues methods, though all these methods are used to detect isomorphism among a group of PGTs. Whereas with the Hamming number approach, one can detect isomorphism, symmetry and number of possible level combinations of an PGT with a single hamming matrix.

A semi-analytical method applied to turbocharger engine model

In this study, we apply a new version of the Homotopy Analysis Method called decomposition of the homotopy analysis method (DHAM). The DHAM method is based on the decomposition of the right-hand side of a given system of differential equations into a sum of functions. After the decomposition one can apply the HAM method. The physical model that we investigate in this paper is a complex system of equations that contains nonlinear ordinary differential equations of the first order. The system of equations takes into account the important variables such as the pressure, the temperature, the mass flow, the torque due to the turbine turbocharger, the torque from the compressor, the speed of turbocharger, etc. This system is very complex and cannot be solved analytically. The HAM method includes an artificial small parameter that inserts into the physical model and hence it enables one to apply different asymptotic methods. We compared the results of DHAM and HAM to numerical simulations analyses. We concluded that the DHAM results are closer to the numerical simulation results.

Comparison between hamming method and modified path matrix approach to identify isomorphism in PGTs

Structural Synthesis and Analysis plays a major role in identifying the Isomorphism and Symmetry of a Planetary Gear Train (PGT). In synthesis process, detection of isomorphism in PGTs with given number of links and Degree of Freedom (DOF) is essential. One gear pair and one turning pair will be added to the existing link to generate next level PGT. One isomorphic PGT is selected at random to generate higher link PGTs. Graph theory and matrix methods are used by different kinematicians to identify the symmetry and isomorphism in PGTs. Every method has its own merits and demerits. In this paper a comparison was made between the Hamming number technique and Modified Path Matrix (MPM) approach. For easy analysis, PGTs are converted in to graphs and matrices are extracted from these graphs. In this paper isomorphism is checked by using Adjacency matrix and Modified path Matrix. 4-link and 6-link PGTs were considered for analysis in both the methods and compared the results. It is observed that Hamming Number approach is simple and feasible method among the two to identify the symmetry and isomorphism in PGTs.

الحل التقريبي لمعادلة بواسون غير الخطية بطريقة هوموتوبي_العناصر المنتهية FE_HM

عرّفنا في بحثنا هذا زمرة هايزنبرغ، وهي الزمرة الأكثر شهرةً من زمر لي. ثمّ ناقشنا نظريّة التمثيل لهذه الزمرة، إضافةً إلى العلاقة بين نظريّة التمثيل لزمرة هايزنبرغ، ومؤثرات كميّة الحركة والموضع. وهذا ما يُبيّن لنا كيفية تحقيق الترابط بين زمرة هايزنبرغ والفيزياء. ثمَ درسنا خصائص دوال هرميت، ودوال هرميت الخاصّة. إنّ هذه الدوال هي دوال ذاتيّة لمؤثرات هرميت، ومؤثرات هرميت الخاصّة على التوالي. يُطلق عادةً على مؤثر هرميت اسم الهزّاز التوافقي (Harmonic oscillation), ويُطلق على مؤثر هرميت الخاص اسم مؤثر لابلاس الملتوي (twisted Laplacian). ويرتبط كلٌ من هذين المؤثرَين بمؤثر لابلاس الجزئي على زمرة هايزنبرغ. هذا وإنّ نظريّة مناشير هرميت، ومناشير هرميت الخاصّة ترتبط ارتباطاً وثيقاً بالتحليل التوافقي لزمرة هايزنبرغH^n، كما أنّها تلعب دوراً هامّاً في فهمنا للعديد من المسائل في H^n.

Free surface film flow of an unsteady second grade fluid over a stretching sheet with surface tension linearly varies with temperature

In this investigation, the work of Noor and Hashim (2010) is explored in a more advance form by considering the effectiveness of the second grade boundary layer equations with the adjust of pressure term in the presence of transverse magnetic field. The conducted unsteady momentum equations in xy-plane attached with energy equation are shifted into a group of two ODEs involving the important physical parameters, having effective results for the constructive progress. These parameters are second grade non-dimensional parameter, surface tension parameter(thermocapillary number), temperature Grashof number, sheet thickness, magnetic parameter(Hartmann number), Prandtl number and non-dimensional parameter of unsteadiness. The same system give local free surface temperature, heat transfer(heat flux) normal to the flow surface and local surface skin friction. All observations are possible by the use of Homotopy Analysis Method called HAM. Graphs and Tables are made to see the physical properties of the fluid flow by varying arbitrary parameters. Error analysis is a part of this study which define the validity of the HAM method. Further, comparison of the methods(HAM and BVP4C) are done in a table for the validity of the solution.

A stability prediction method research for milling processes based on implicit multistep schemes

Chatter suppression during milling operations is of great significant for tool life, surface quality, and cutting efficiency. Based on the Hamming and Simpson methods, a Hamming–Simpson–based method is presented in this paper for accurately and efficiently determining the milling stability. The milling dynamic model with consideration of the regeneration effect is expressed by delay differential equations (DDEs) with time-periodic coefficients. After separating the tooth-passing period into two different phases, the two linear multistep methods are simultaneously adopted to estimate the state term by discretizing the forced vibration phase into time intervals of equal length. Subsequently, the state transition matrix can be determined over one period and the chatter-free borderline can be searched according to the Floquet theory. On this basis, the precision and efficiency of the Hamming–Simpson–based method are analyzed in detail through comparing with the three benchmark methods. Analysis results indicate that the Hamming method is required to convert variables which may affect the prediction accuracy. To overcome this shortcoming and promote the computational accuracy, a three-step implicit multistep exponential fitting method is applied to predict chatter stability; meanwhile, the Simpson method is responsible for the correction of the prediction. The effectiveness of the proposed method has been comparatively analyzed through two benchmark examples. Numerical simulations illustrate that the proposed method exhibits better prediction accuracy and computational efficiency.

Comparison of Milne-Simpson Method and Hamming Method in Logistic Equation Settlement on Pert Prediksi the People of Bandar Lampung City

Milne-Simpson method and Hamming method are a numerical method that can be applied in the calculation of population prediction in the future as a reference government in building an area. Beginning with the calculation of growth rates with logistic equations then processed into the fourth-order Runge-Kutta method. The recalculation process continues to search for the smallest error between the Milne-Simpson method and the Hamming method. Error calculation is done with population growth rate 5.2% with step size h = 1 and capacity of Bandar Lampung city 1.500.000 soul. Numerical solutions show population growth annually and Milne-Simpson method is the best method seen from the smaller error than the Hamming method error.

Soret and Dufour Effect on MHD Jeffrey Nanofluid Flow towards a Stretching Cylinder with Triple Stratification, Radiation and Slip

In this paper investigation is done on the MHD Jeffrey nanofluid flow towards a stretching cylinder in the presence of non-linear thermal radiation, triple stratification, Soret and Dufour and slip. The governing equations are transformed into ordinary differential equations by using suitable transformations. The HAM method is used to solve these equations. The temperature profile and local Sherwood number increase when Dufour number is hiked where as local Nusselt number fall off. While increasing local Soret number, the concentration profile increases where as Sherwood number decreases.

Hamming method for solving uncertain differential equations

Uncertain differential equations are important tools to model continuous time varying uncertain phenomena. When analytic solutions become unreachable, numerical solutions provide us important alternatives to solve uncertain differential equations. This paper presents a linear multi-step method, Hamming method, for solving uncertain differential equations. Numerical example shows that the Hamming method is more efficient and effective than the general linear one-step method (e.g. Euler method and Runge–Kutta method). Finally, extreme value and time integral of solutions are also given via Hamming method for illustrating purpose.

Numerical model and multi-objective optimization analysis of vehicle vibration

It is crucial to conduct a study of vehicle ride comfort using a suitable physical model, and a precise and effective problem-solving method is necessary to describe possible engineering problems to obtain the best analysis of vehicle vibration based on the numerical model. This study establishes different types of vehicle models with different degrees of freedom (DOFs) that use different types of numerical methods. It is shown that results calculated using the Hamming and Runge-Kutta methods are nearly the same when the system has a small number of DOFs. However, when the number is larger, the Hamming method is more stable than other methods. The Hamming method is multi-step, with four orders of precision. The research results show that this method can solve the vehicle vibration problem. Orthogonal experiments and multi-objective optimization are introduced to analyze and optimize the vibration of the vehicle, and the effects of the parameters on the dynamic characteristics are investigated. The solution F 1 (vertical acceleration root mean square of the vehicle) reduces by 0.0352 m/s2, which is an improvement of 7.22%, and the solution F 2 (dynamic load coefficient of the tire) reduces by 0.0225, which is an improvement of 6.82% after optimization. The study provides guidance for the analysis of vehicle ride comfort.

SOLVING FRACTIONAL INTEGRO DIFFERENTIAL EQUATIONS BY HOMOTOPY ANALYSIS TRANSFORM METHOD

In this paper, we introduce an analytical method, which so called the homotopy analysis transform method (HATM) which is a combination of HAM and Laplace decomposition method (LDM). This scheme is simple to apply linear and nonlinear fractional integro-differential equation and having less computational work in comparison of other exiting methods. The fractional derivatives are described in the Caputo sense. The most useful advantage of this method is to solve the fractional integro-differential equation without using Adomian polynomials and He’s polynomials for the computation of nonlinear terms. AMS Subject Classification: 00A71, 45A05, 34A12, 45E10, 7Q10

Identification of Isomorphism in Nine Links Two Degree of Freedom Kinematic Chains Using Hamming Method

Isomorphism identification is a difficult problem in kinematic chains (KC). There are a number of methods proposed by many researchers to detect the isomorphism and inversion of kinematic chain but each has its own shortcomings. Purpose of this paper is to give an efficient and reliable method for detection of isomorphism and inversion among the KC which can be less time consuming among many other related techniques. An attempt has been made to provide satisfactory solution to detection of isomorphism by using Hamming method. The Hamming Number is computed by using the direct method of writing the Hamming matrix, which save time and effort. Link Hamming string which is defined as the string obtained by concatenating the link Hamming number and the frequency of individual Hamming numbers in that row is then formed. Finally, chain Hamming string defined as the string obtained by the concatenation of the chain Hamming number and the link Hamming strings in descending order is formed. This method is implemented on the nine links two degree of freedom.