Статьи журнала - International Journal of Engineering and Manufacturing
Все статьи: 508
Modeling Changing Graphical Structure
Статья научная
We introduce the graphical models to describe the changing dependency structure between multivariate time series and design the algorithm by the markov chain monte carlo method. The model is applied to the stock market of Shanghai in China to study the changing correlation of five segments of the market, empirical results show that there is stronger dependency structure in the bear market and weaker correlation in the bull market.
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Modeling and Real-Time simulation of large hydropower plant
Статья научная
In this paper, modeling and simulation of large hydropower plant in real-time platform named Real-Time Laboratory (RT-LAB) is carried out. First, a hydropower plant model consisting of nonlinear hydro turbine with PID governor and synchronous generator (SG) with DC1A excitation system and connected to grid is developed in MATLAB/Simulink environment. This model is then simulated in RT-LAB after the modification of MATLAB/Simulink model required for suitable operation in RT-LAB environment. Finally, the real-time simulation of hydropower plant when subjected to disturbances of load addition, reduction of load and short circuit fault analysis is presented and discussed.
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Modeling and Simulation of an Indirect Natural Convection Solar Dryer with Thermal Storage Bed
Статья научная
The intermittent nature of solar energy limits a 24 hour operation and the effectiveness of solar thermal devices. Affordable and environmentally friendly materials for storing solar energy are currently in search. A natural convection solar cabinet dryer coupled with thermal energy storage bed (gravels) is modeled and simulated for space heating application (tomatoes drying) using TRNSYS 16 software. Performance of the solar thermal system (solar cabinet dryer) with a thermal storage bed will serve as a guide in developing a gravel-pit (GP) and or water-gravel pit storage system (WGPS) on a medium to large scale to facilitate solar thermal storage of heat for space and water heating applications in homes, health care and educational facilities. Thermal storage volume and thickness of gravel bed were determined and an optimized solar collector area obtained using TRNSYS 16 software for drying 6kg of tomatoes slices. A computer program was written to predict the product drying temperature, mass of moisture removed, moisture content and drying rate at two different trays including solar collector efficiency, heat storage bed temperature profile using meteorological data input of dryer location, gravel properties, solar collector parameters and solar cabinet dryer chamber variables. The month of August was used as the design month bearing in mind that it has the least solar radiation in Bauchi and thus, predicted the least drying performance while, the month of March with the most solar radiation predicted the optimum drying performance. The maximum predicted gravel bed temperatures were 44 and 59.3°C for the months of August and March respectively. Predicted performance of the solar cabinet dryer was compared to a similar cabinet dryer without thermal storage bed. Predicted maximum product drying temperatures of 48 and 69°C were obtained for solar cabinet dryer with thermal storage bed as against 46 and 66°C for solar cabinet dryer without thermal storage bed in the month of August and March corresponding to solar intensity value of 575.4 and 1049.2W/m2 respectively. To attain 4.5% moisture content for 3kg of tomatoes slices placed on each tray containing 94% of moisture, requires 37 (20 hours of sunshine and 7 hours of supplementary heat stored) and 53 (26 hours of sunshine and 6 hours of supplementary heat stored) hours of drying for solar cabinet dryer with thermal storage bed and, 52 (25 hours of sunshine) and 75 (34 hours of sunshine) hours under same weather condition for similar solar cabinet dryer without thermal storage bed for the month of March and August respectively. The average moisture extraction rate is 0.0759 and 0.0531kg per hour in the month of March for solar cabinet dryer with and without thermal storage bed and, 0.0540 and 0.0374kg per hour the month of August respectively. Predicted maximum solar collector efficiency for cabinet dryer with thermal storage bed is 50.12 and 43.85% for the month of March and August whereas, it was 45.83 and 37.66% for cabinet dryer without thermal storage bed respectively. The performance prediction of the solar cabinet dryer with thermal storage bed indicates clearly good potential for storing solar thermal heat collected during the day and effectively utilizing the stored heat during off-sunshine hours for heating applications. It is recommended that a gravel-pit (GP) and or water-gravel pit storage system (WGPS) should be developed and adequately studied for a range of operating parameters based on temperature distribution, thermal energy stored, available energy stored in the bed, energy consumption by blower (for active bed), and thermal efficiency of the collector to give clear guidelines for using the gravels for large scale solar thermal energy storage for space and water heating applications.
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Статья научная
In this paper, a novel method based on online monitoring of Instantaneous Exciting Current Space Phasor is presented in order to detect inter-turn faults on the transformer windings. This approach detects winding faults by comparison between presentation of the Instantaneous Exciting Current Space Phasor under healthy and faulty condition. In this work, the angular speed of Instantaneous Exciting Current Space Phasor has been introduced as one of the fault detection tools that has good sensitivity for detection of minor inter-turn faults. Firstly, a typical transformer is simulated based on Finite Element Analysis (FEA) to investigate the transformer behavior under different conditions. Then, the accuracy and performance of proposed diagnosis technique are studied by applying it to the simulated transformer.
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Modelling of Air Standard Thermodynamic Cycles Using CyclePad
Статья научная
The paper aims to explore the application of CyclePad in modelling air standard thermodynamic cycles. CyclePad is a powerful software tool designed for the simulation and analysis of various thermodynamic cycles. This paper provides an in-depth investigation into its capabilities and effectiveness in modelling air standard cycles, including the analysis of performance parameters such as efficiency, work output, and heat transfer. To explore the potential of CyclePad, Carnot, Otto, Stirling, Ericsson, Diesel, and Dual cycles were explored first thermodynamically and then modelled using the software. These cycles were tested against practical numerical problems, and it has been observed that the results obtained from the CyclePad are in agreement with the existing literature. Moreover, to understand the impact of input parameters on the performance of cycle output and efficiency sensitivity analysis was performed and reported. The results obtained are very encouraging and stem from the fact the CyclePad can be used effectively to understand and analysis any thermodynamic cycle (both open and close) having any level of complexity.
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Modular Approach based Backbone Construction Using STP with CDS
Статья научная
In a dense environment, wireless sensor network (WSN) requires more energy to work in an effective and efficient manner. Hence, energy conservation is the main objective. In the paper, we have proposed a methodology to construct a backbone using modular antennas in combination with spanning tree protocol (STP), graph sampling, and Connecting Dominating Set (CDS) strategy. The backbone construction is based upon the modular antenna based WSNs, where the dominating sets can avoid the intermediate connection in order to reduce the hop count and energy consumption. The dominating sets have been connected using the modular transmission range of the wireless sensor networks to construct the backbone. The dominating set selection procedure to construct the WSN backbone is based upon the degree of connections of the nodes, which enables the locally centralized behavior of the connected dominating sets. The proposed methodology has been proved effective resulting in the construction of an energy efficient backbone.
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Статья научная
The objective of the present paper is to optimize the machining parameters for turning of EN8steel on lathe machine using a combination of Taguchi and Grey Relational Analysis to yield minimum cutting forces and surface roughness. The process parameters such as rotational speed, feed, depth of cut and cutting fluid have been selected. In this study, the experiments were carried out as per Taguchi experimental design and L9 orthogonal array was used. Analysis of variance (ANOVA) was also used to find out the most influence of processing parameters on the responses. The regression equations were also established between the process parameters and responses. The results indicate that the depth of cut is the most significant factor affecting the cutting force and surface roughness followed by a feed, speed and cutting fluid.
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Multi-Sensor Approach for Monitoring Pipelines
Статья научная
Pipeline vandalization is one of Nigeria's economy killer, since Nigeria economy to a great extent relies on oil in that capacity. Therefore, a third party damage to petroleum pipelines can be cataclysmic if undetected and prevented. This act results in budgetary misfortunes, ecological contamination and incessant death and loss of properties worth millions as an aftereffect of vandalization. Consequently, it is very paramount to protect these pipelines from vandals through intelligent monitoring systems. Several efforts have been made towards providing a reliable monitoring system for oil pipeline, however, no practically implementable solution have been achieved. Therefore, a pipeline monitoring system using multi-sensors is presented herewith. The sensor array consists of a Passive Infrared (PIR), vibration and sound sensor. An uninvolved infrared (PIR) sensor was utilized to detect intruders before they get in contact with the pipeline and for affirmation of intruders, sound and vibration sensor were set up. As the PIR recognizes an on-coming human the sound and vibration sensors affirms if the human is an intruder(s). An intrusion message containing the location of the vandals is sent to the appropriate authority by the microcontroller via a connected GSM module. Results obtained proved the system as a viable solution for detecting pipeline vandals.
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Multiple Master Communication in AHB IP using Arbiter
Статья научная
The major disadvantage of a standard bus topology is the constraint of being able to realize only one communication at a time (the tasks may take place in parallel but the communications are only done in a sequential). As these communications are handled by the bus arbiter, a Bottleneck when the number of communications increases, but also when the bandwidth constraints of several communications become important.This arbitration plays a predominant role because it authorizes communications on the bus but it is also in charge of resolving the conflicts (several requests of communications at the same time). This arbitration implies therefore a limitation on the number of IP connected to the bus to a dozen elements. This work elaborates the AMBA bus interface with four masters interacting with single memory system, using Arbiter between memory controller and other supporting peripherals. Different module of i.e., AHB MSTER, AHB SLAVE INTERFACE AND AHB ARBITER(round robin algorithm)has been developed with VHDL. Further integration with FIFO, RAM and ROM with memory controller is done. The Four AHB master initiates the operations and generates the necessary control signals on single bus to memory controller with the help of arbiter. The proposed architecture shows the area efficient management as compared to previous researches of multiple data communication in AHB BUS system. The system model is synthesized with Xilinx XC6vx75t-2ff484 and simulated with MODELSIM.
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Статья научная
In this paper, we study the two-point boundary value problems for systems of nonlinear third-order dierential equations .Under some conditions, we show the existence and multiplicity of positive solutions of the above problem by applying the fixed point theorems in cones.
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Multiple-address Technique of Satellite Communication
Статья научная
In this paper, we have studied the operation modes of satellite communication system. They include that signal transmission mode, signal processing mode and signal exchanging mode. We have especially studied the multiplex mode, modulation mode, coding mode, multiple-address connection, and channel distribution and exchanging system. All we have studied are important to the satellite communication station’s changing and signal processing.
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NB-IoT based Status Measurement System for 33kV Power Distribution Networks in Smart Grids
Статья научная
In the recent decade, there has been a lot of focus on developing intelligent systems and appliances to suit the century's needs and make life easier. During the same period, the electric power industry introduced Smart-Grid, a crucial innovation to meet today's electric supply-demand and effectively use electric resources. The smart grid is an aspect of the electricity industry's evolution and reformation. An electrical power grid is a complex system consisting of generation, transmission, distribution, storage, and utilization. Coordinating these systems further increases the complexity of this interconnection of systems. The existing power distribution system available in the industry consists of monitoring equipment such as Supervisory Control and Data Acquisition(SCADA) to monitor some network parts. However, there's no automated way of monitoring power outages or load current flow in some sub-sections of the distribution line. Physical inspection is not convenient as it's more time-consuming.Moreover, these sub-sections may have up to ten distribution transformers or even could be more. In this work, A novel IoT-based power line monitoring system has been introduced to overcome those issues. Narrow Band Internet of Things(NB-IoT) is used in this system as the primary wireless technology. A current sensor measures electrical line currents, and sensor values are pushed to a remote IoT cloud. Implemented system tested in several 33kV power lines and result and performances of the system is presented.
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Nanotechnology Innovations and Commercialization-Opportunities, Challenges & Reasons for Delay
Статья научная
Innovations in nanotechnology are making a revolution in manufacturing and production, creating new materials and products through novel processes for commercial applications. New products based on nanotechnology with novel characteristics are continued to grow and benefit the society. Being general purpose technology, nanotechnology is expected to support all fields of the society, but some fields like medicine, energy, environmental remediation, robotics, manufacturing, commerce, and space exploration are expected to undergo explosive developments. In this paper, we made a detailed analysis of advantages, benefits, constraints, and disadvantages of progress in nanotechnology for the society and discussed the reason for the failure of estimated timeline for realizing various generations of progress and proposed a modified timeframe for anticipated nanotechnology innovations. Based on the business perspective, we have developed a nanotechnology products/services commercialization model and discussed the opportunities for nanotechnology commercialization. The paper also contains a detailed analysis of common commercialization challenges faced by nanotechnology firms including time lag, the valley of death, lack of infrastructure, lack of a standard for evaluation, bureaucratic delays, the dearth of funding, and lack of trained professionals, brand image, and public support. Finally, we have mentioned how the various corporate business strategies can be used in the successful business of nanotechnology products and services.
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Neural Network Recognizes Fruit Fly's Wing Vibration Sound Based on Hilbert-Huang Transform
Статья научная
The paper applies Hilbert-Huang Transform to process the fruit fly's wing vibration sound. Firstly, it gets Hilbert-Huang spectrum and marginal spectrum of the wing vibration sound of two different strains of fruit fly in the same species. Then, it analyzes differences of the energy size and the energy distribution, and extracts features including the relative energy, time-frequency entropy and the cumulated amplitude value of marginal spectrum. Finally, recognizes two different strains of fruit fly by BP neural network and obtains a satisfying result. The experiment result verifies effectiveness and feasibility of the feature extraction, and the paper offers a new evidence for the study of discrimination in intraspecies relationship of fruit fly.
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Статья научная
Controlling drum level is a major and crucial control objective in thermal power plant steam boilers. The drum level as a controlled variable is highly characterized by complex non-linear process dynamics as well as measurement noise and long-time delays. Developing a data-driven process model is particularly advantageous as it could be built from ongoing operational data. Such a model could be used to assist existing controllers by providing predictions regarding the drum level. The aim of this paper is to develop such a model and to propose a control architecture that can be easily integrated into existing control hardware. For that purpose, different neural networks are used, Multilayer Perceptron (MLP), Nonlinear Autoregressive Exogenous (NARX), and Long Short Term (LSTM) neural networks. LSTM and MLP were able to capture the dynamics of the process, but LSTM showed superior performance. The results demonstrate that the use of traditional machine learning criteria to evaluate a process model is not necessarily adequate. Using the model in an open-loop and a closed-loop simulation is more suitable to test its ability to capture the dynamics of the process. A novel architecture that integrates the process model within an existing closed-loop controller is proposed. The architecture uses adaptive weights to ensure that a good model is given more influence than a bad model on the controller’s output.
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Neural Spike Feature Extraction of Globus Pallidus Based on Wavelet Package Decomposition
Статья научная
In this study, features of neural signal recordings with microelectrode injected into the internal globus pallidus of non-human primates before and after 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) treatment which induces Parkinson’s disease (PD) were investigated. Neural oscillations were analyzed using the measure of wavelet spectrum and singular value extraction. Differences in the time-frequency analysis were observed between groups. Results showed that the PD states had significantly higher amplitudes of spectrum. Singular values extracted from wavelet coefficients after wavelet package decomposition were used to differentiate pathological changes from normal states, and the singular values of the reconstructed wavelet coefficients of the PD states were statistically smaller than controls. We speculate that the irregular high frequency oscillations and reduced singular values observed in the pathological firings are consistent with the previous view that a loss of information transmission in the neural circuitry underlies PD and these measurements could be of diagnostic and monitoring values of the disease state.
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New Method Simulating Flexible object-operator Cube Model
Статья научная
In order to represent complex graph drawing in the course of 3-dimensional dynamic simulating flexible objects such as fabric、garment、rope、netting yarn and rubber band, we designed a new mathematic model named operator cube. Any graph formed on the basis of the point information. In a word, if each point has enough geometry information, the graph can be drawn and rendered. Operator cube model came into being just because of that idea. The paper mainly discussed the theory of operator cube model. The model can transform a complex graph into a simple representation effectively and in real time, especially in the course of topology structure varying flexible object simulation. What’s more, the model can accurately express the simulation results. The model converted between the world coordinate system space and device coordinate system space. And the model and the conversion involved some profound mathematic theorems and our conclusions which were proved strictly.
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Статья научная
Over the years, process safety management (PSM) program development and implementation has benefited the operating facilities in terms of successful avoidance of process safety incidents, and related business losses arising due to equipment damage, production interruption and environmental damage. PSM covered facilities have also reported improved personal injury record through successful implementation of an applicable, regional PSM standard. However, there is still a need to address both the efficiency and effectiveness aspects related to non-digital (manual) PSM program development, implementation, audit, and compliance. There has been continuous reporting of significant process safety incidents even after the promulgation of process safety management regulations both in the United States and globally. The uncertain macroeconomic and political conditions have also forced the governments to allocate less than required fiscal budget to their regional regulatory bodies to address any ongoing operational efficiency concerns in successful enforcement of their PSM regulation. This research paper will investigate and discuss the key issues faced by both the government regulatory bodies and process plant facilities, with the current non-digital (manual) method of PSM implementation, audit, and compliance. Moreover, recent modernization initiatives of safety regulations undertaken by federal regulatory bodies such as OSHA and EPA in the United States are described and discussed in the context of achieving the PSM compliance effectively and efficiently. The paper will also discuss detailed comparison between OSHA’s 1992 regulatory impact analysis study and 2023 information collection requirement burden hour and cost estimate and will outline a methodology to estimate the total economic burden of PSM compliance on the existing and future PSM covered facilities in the United States. The methodology to adjust (correct) OSHA’s PSM compliance cost estimates are based on accounting key regulatory, industrial, organizational, and economic factors prevalent in the global process plant industry.
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Novel Approach of Surface Unfolding for Ceramic Bowls
Статья научная
Recent years, the significant advantage has been taken by ceramic industrial from the strong evolution in automation. All production phases have been addressed through various technical innovations, with the exception of the final stage of the manufacturing process. When applying computer vision on ceramic product quality inspection, the different kind of product of ceramic makes it difficult, especially on ceramic bowls, which have a curved surface. It is difficult to analyze rapidness and catch the production rate. This paper proposed an approach for automatic surface imperfection inspection of ceramic products. The bowl’s curved surface unfolding model was discussed derived from helicoid unfolding method. Experiment shows that this method can be nicety.
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Статья научная
Numerical study simplifies the challenges associated with the study of moderate and intense low oxygen Dilution (MILD) combustion. In this study, the numerical investigation of turbulent non-premixed combustion in a Delft Co-flow Burner presents, which emulates MILD combustion behaviour. MILD combustion yields high thermal and fuel efficiency along with very low emission of pollutants. Using commercial ANSYS software, this study focuses on assessing the performance of two different turbulent-chemistry interactions models: a) Eddy Dissipation Concept (EDC) with reduced chemical kinetic schemes with 22 species (DRM 22) and b) Steady Diffusion Flamelet model, which is adopted in the Probability Density Function (PDF) approach method using chemical kinetic schemes GRI mech 3.0. The results of numerical simulations are compared with available experimental data measurement and calculated by solving the k-epsilon realizable turbulence model for two different jet fuel Reynolds numbers of 4100 and 8800. It has observed that the Steady Diffusion Flamelet PDF model approach shows moderately better agreement with the predicting temperature fields of experimental data using chemical Mechanism GRI mech 3.0 than the EDC model approach with a chemical mechanism with DRM 22. However, both models perform a better understanding for predicting the velocity field with experimental data. The models also predict and capture the effects of lift-off height (ignition kernel) with increasing of fuel jet Reynolds number, Overall, despite having more computational cost, the EDC model approach with GRI mech 3.0 yields better prediction. These featured models are suitable for the application of complex industrial combustion concentrating low emission combustion.
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