International Journal of Engineering and Manufacturing @ijem
Статьи журнала - International Journal of Engineering and Manufacturing
Все статьи: 571
Comparison of OFDM System in Terms of BER using Different Transform and Channel Coding
Статья научная
Orthogonal frequency division multiplexing is a type of multicarrier modulation technique which is used in wireless communication. OFDM can be used in various wireless and wired application such Digital audio broadcasting, digital video broadcasting & wireless LAN. The Performance of OFDM system depends on various parameters such as using different transform, different modulation and by putting various channel coding. In this paper OFDM system is modeled by using different transform (DWT/FFT), different modulation (BPSK, QPSK, QAM) and different channel coding (Linear / Cyclic block codes) for AWGN channel. The performance parameter is calculated as Bit error rate (BER) for various transform/modulation/channel coding based OFDM systems. MATLAB Simulink tool is used to calculate the bit error rate (BER).
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Статья научная
The determination of strength properties i.e., compressive strength (CS) is essential to estimate the load at which the concrete members may crack especially in aggressive environment. The paper reports an experimental investigation on deterioration of used engine oil (UEO) soaked concrete with respect to its strength properties. Also, it is found that this deteriorating effect is lessened with partial replacement of silica fumes (SF). The CS analysis was done with a water-concrete ratio of 0.49 with nine percentage replacements of SF (0, 5, 10, 15, 20, 25, 30, 35, 40 and 45) with water curing and UEO soaking. The soaking in two different liquids was essential in order to throw light on the detrimental effects of UEO on the CS of concrete. The results of the experiments showed that 20% replacement of SF in concrete was optimum to attain maximum CS. A mathematical model based on Abrams’ law has been developed to evaluate the strength characteristics of concrete subjected to UEO soaking. The developed model facilitates the prediction of CS based on curing time in water and soaking time in UEO and also the quantity of SF used. The accuracy of the developed model is evaluated and good agreements with the ground truth values are found.
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Computational method investigation of solid ducted rocket
Статья научная
The Computation method of Solid Ducted Rocket (SDR) is a complex problem. It needs to effectively solve the two mixing and combustion processes, and is also affected by many factors such as the overall scheme and propellant type. In order to find a suitable method, physical model, simplified hypothesis, control equation, turbulence model, combustion model, etc. were investigated. Subsequently, calculations were carried out based on the Vanka model, and finally the results of pressure, temperature and combustion efficiency were obtained. The results show that the proposed method is practicable, and the accuracy and efficiency are ideal. Combustion efficiency is only 77.4%, and the Vanka model must be further improved by the air and gas intake modes. The results can provide reference for relevant research.
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Construction of Health Promotion Management System Based on Web
Статья научная
Health management is a new service for healthy and sub-healthy people in modern medical institutions, which will help to instruct people how to effectively control and maintain their health. Through questionnaire, systematic analysis and software engineering, the structure and function of health promotion management system are analyzed and designed. Finally, the health promotion management system based on web is constructed. People become willing to take advantage of the system to manage and direct their own health instead of becoming victims of diseases.
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Control of Switched Reluctance Motor and Noise Reduction Using Fuzzy Controller in Matlab/Simulink
Статья научная
Switched Reluctance Motor (SRM) has been successfully used for its excessive efficiency and higher strength to torque ratio. However, the only demerit it has its radial pressure and acoustic noise. When SRM achieves higher speeds, it tends to generate more force between stator and as a result acoustic noise with higher decibels is a concern. In this paper, a layout is used for reduction of both radial force and acoustic noise for eight/6 SRM using the fuzzy logic controller by controlling the speed and current as a feedback loop. The mathematical models are framed to resolve glitches associated to radial pressure and acoustic noise. In this proposed method the SRM produces a very low noise level when it rotates at the speed of 1200 RPM. This method also has been implemented in MATLAB/Simulink platform mainly to reduce the acoustic noise at higher speed in SRM.
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Convergence of SAOR Method for the Linear Complementarity Problems
Статья научная
In this paper we apply an iterative method, the SAOR method for solving the linear complementarity problem, and some sufficient conditions for the convergence of the new method are presented when the system matrix M is an M-matrix. Moreover when M is an L-matrix, we discuss the monotone convergence of it. Finally, we report the numerical results of our proposed method.
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Corrosion Assessment of some Buried Metal Pipes using Neural Network Algorithm
Статья научная
The key aim of this assessment is to characterize the rate of corrosion of buried Nickel plated and non-plated AISI 1015 steel pipes using a Modified Artificial Neural Network on Matlab and taking the oil and gas area of Nigeria as a case study. Ten (10) metal specimens were used. Five (5) were nickel electroplated specimens buried differently in 5 plastic containers containing 5 different soil samples with the other 5 non-plated specimens also buried into the same 5 soil samples but different plastic containers. In carrying out the experiment, the data that was collected for 25 consecutive days were grouped into sets of input and output data. This was required so as to appropriately feed the modelling tool (Artificial Neural Network). The input data were; temperature of the soil sample, temperature of the immediate surroundings, and pH of the soil sample while the output data was weight loss. Conclusively, Modified Artificial Neural Network relationships between the varied selected input parameters that affects corrosion rate (soil sample temperature, immediate environment temperature and pH value) and the output parameter (Corrosion Penetration Rate) were derived. Also, soil sample temperature and the immediate surrounding temperature combined conditions had the strongest effect on corrosion penetration rate while the immediate surrounding temperature and the pH value combined conditions had the weakest effect on corrosion penetration rate.
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