Mehran University Research Journal of Engineering and Technology
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Mehran University of Engineering and Technology,正常發行
選擇卷期
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The world is tilting more and more towards technology and the use of mobile devices is getting usual day by day. The majority of the user who use these gadgets are younger in age and belong to student class mostly as the mature the age is the learning curve is less responsive; that makes the equipment very evident for the learning. The aim of the proposed application is to promote the positive use of smart phones in the classroom to motivate students towards effective learning, where the goal of learning is achieved through the environment and fellows. By using the inquiry-based learning approach, the application provides a platform for the students to design, share and discuss their own questions with their class fellows. Technology-enabled active learning is a learning format that boosts the factors that affect the overall learning environment. The process starts in between them the eagerness to learn through their own interest and the environment they create amongst their institutes. The android application allows the users to access quiz, forum, view each other's profile, including their statistics and ranking; while the web-based activity management application allows the administrator to manage, monitor, and control different aspects of the system.
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CHQ (Cold Heading Quality) steels are assumed to be non-heat treatable so strengthened by cold forming which is a quick and mass production makes it low cost manufacturing process. In this study, microstructure and phase transformation in steels is a fundamental aspect of governing the properties. A large number of studies are dedicated on the subject phase transformations owing to availability of several commercial steel grades. Due to several grades of steels commercially available shows differently behavior so it is hard to conclude that phase transformation is universally understood completely. In this study the influence of heating rate on the development of microstructure of CHQ steel has been studied thoroughly by using different heating techniques. For characterization, optical microscope connected with high resolution camera and SEM (Scanning Electron Microscope) was utilized to interpret the microstructural results. In addition, heat treatment methods have been utilized as to vary the microstructure in the steel under experimentation. It was found that heating rate could have major effect on phase transformation of CHQ steel (under study). Rate of heating enhances the austenite development kinetics with respect to dwell time and such austenite has been changed to martensite upon cooling. In addition, heating rate also promotes nucleation sites for the formation of austenite phase of CHQ steel.
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HAR (Human Activity Recognition) system becomes complex, inefficient and less accurate as we keep on adding new activities into the system; because it follows a specific procedure for activity recognition, from raw data collection to classification. In this study, we discuss an adaptive system to improve recognition accuracy. We developed a mathematical model to categorize the activities based on their data pattern. It observed that as we group the activities; although a separate classification model is required for each group, but it increases the recognition accuracy and efficiency of the system. The experiments on the data of eleven activities gathered from 10 volunteers proved the usability, scalability and effectiveness of our proposed methodology. The recognition accuracy of eleven activities was increased in total about 9- 37% and reached up to 90% in different cases, using different number of groups and classification algorithms.
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This paper confers one of the three phases of tree multipliers, i.e. the Partial Product reduction phase. In this paper four types of hybrid tree multipliers are studied and proposed using parallel counters (full adders and half adders) for reduction of Partial Products in multiplication operation. After ANDing the bits of multiplier and multiplicand, the Partial Products are arranged into two groups for reduction, each group uses a different technique for reduction of Partial Products, resulting in a fewer gates than the parent tree reduction techniques. The results of the proposed tree reduction techniques are then tabulated and compared with the parent tree multipliers. The performance comparison is done in terms of number of gate counts of half adder and full adders used in the Partial Product reduction phase. Four types of hybrid tree multipliers are presented using CSA (Carry Save Adder) Array multiplier, Wallace Tree multiplier, Modified Wallace Tree multiplier and Dadda Tree Multiplier. The results show significant reduction in number of full adders and half adders with the slight overhead of increased final addition stage of the hybrid multiplier. The proposed multipliers can prove to be the better choice for digital signal processing designs, image processing designs and processor architecture.
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Majority of the developing countries are facing problem of low supply voltage coupled with shortage of electrical energy. There is a growing concern for ways and means to preserve the existing resources and optimize the performance of EPDS (Electric Power Distribution System). Poor condition of distribution network, utilization of low current carrying capacity conductors with overloading is mainly causing the voltage drop, power loss and energy loss in the LVDN (Low Voltage Distribution Networks). Most of developing countriesare encountered with financial problems to ward up gradation of the existing network. Under such circumstances, it is essential to optimize the low voltage distribution network using innovative approach to design the LVDN. In thiswork, ahybrid rehabilitation techniqueis used for the performance improvement of LVD utilities network. Most of the availablealgorithms areconsidering the distribution networks with balance distributed load andunity power factor. The proposed methodology has been applied to LVDN, working under randomly distributed load with low power factor. The technique is applied to improve the efficiency of LVDN in terms of power loss and voltage drop reduction. Optimization of three different circuits of village QutabFerozal, Banth and Pothi Mandra of IESCO, has been selected as a case study. The analysis has been performed using ELR (Energy Loss Reduction) and CADPAD (Computer Aided Distribution Planning and Design) software. Field visits have been conducted to acquire the real data of various LVDN configurations. Simulation results are validated with the actual data of the selected LVDN feeders and found within the permissible limits.
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KG (Knowledge Generation) and understanding has traditionally been a Human-centric activity. KE (Knowledge Engineering) and KM (Knowledge Management) have tried to augment human knowledge on two separate planes: the first deals with machine interpretation of knowledge while the later explores interactions in human networks for KG and understanding. However, both remain computer-centric. Crowdsourced HC (Human Computations) have recently utilized human cognition and memory to generate diverse knowledge streams on specific tasks, which are mostly easy for humans to solve but remain challenging for machine algorithms. Literature shows little work on KM frameworks for citizen crowds, which gather input from the diverse category of Humans, organize that knowledge with respect to tasks and knowledge categories and recreate new knowledge as a computer-centric activity. In this paper, we present an attempt to create a framework by implementing a simple solution, called ExamCheck, to focus on the generation of knowledge, feedback on that knowledge and recording the results of that knowledge in academic settings. Our solution, based on HC, shows that a structured KM framework can address a complex problem in a context that is important for participants themselves.
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LabVIEW Based Simulator for Solar Cell Characteristics and MPPT Under Varying Atmospheric Conditions
Though intermittent, solar energy is a clean and eternal source of energy. PV (Photovoltaic) cell is one of the technology to harness the solar energy and use it as electricity. In recent years rising cost of electricity and environmental concerns have made the solar PV technology a rising research field. In this research field the efficiency improvement is the focal point for the researchers. Because of intermittent weather conditions the output power of the solar cell varies directly to the irradiance level and inversely to the cell temperature and cell never operates at its maximum power. In this paper the characteristics of the sun power A-300 solar cell is simulated in a novel way in LabVIEW using MathScript RT Module along with a MPPT (Maximum Power Point Tracker) using variable step sized incremental conductance algorithm that operates the cell at its maximum power without oscillating at maximum power point. Impacts of changing solar insolation and cell temperature on output curves are also discussed graphically and numerically. The results of the simulation verify the data sheet parameters of sun power A-300 solar cell. Graphs of output power of MPPT indicate the accuracy of the variable step sized InC (Incremental Conductance) algorithm for constant and varying solar irradiance with fast tracking and elimination of steady state oscillations about the MPP which is comparatively better than the conventional MPPT algorithms as compared in the results.
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Bridge pier scouring may lead to the bridge failure and the shape of bridge pier itself is one of the main factor to control scouring around bridge pier. The amount of sediment which is removed from the boundary of bridge pier is called bridge pier scouring and the depth up to which sediment removed is called scour depth. Scouring results, the exposure of foundation, eventually leading to bridge failures. Assessment of the maximum scour that can be faced by pier has a vital role in the design of bridge foundation. Different techniques are used to minimize the scouring effect in order to control the bridge failure. In this study effect of bridge pier shape on scouring was checked on four different shape i.e. circular, oval, square and octagonal. Each pier shape was tested against three different values of flows i.e. 16, 22.50 and 29.50 liter/sec. Uniform bed material of standard deviation (σ_g = 1.21) and median size (D_(50) = 0.28 mm) was used for all tests. Scour is measured with the help of point of gauge and bed is levelled before every experiment. Experimental results show that minimum scour is observed for octagonal bridge pier and maximum for square bridge pier while circular and oval faced intermediate scour depth relative to square and octagonal bridge pier. It is concluded that scour has reduced to 22% when octagonal pier was used compared to circular one.
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Assembly lines are usually used for the mass production. The dawn of mass customization has forced the industries to shift to MMAL (Mixed-Model Assembly Lines). ALBP (Assembly Line Balancing Problem) and MSP (Model Sequencing Problem) are two major problems in MMAL. Sequencing of models is an important aspect of MMAL because improper sequencing can lead to the production loses. This paper dealt with the MSP in MMAL. A modified INEH (Intelligent Nawaz, Enscore, and Ham) algorithm was developed to solve multi-objective MSP. For this purpose, a MCDM (Multi-Criteria Decision Making) techniquewas integrated with NEH. A mathematical model was presented for three performance measures; Idle time, Make-span and Flow Time. A case study of pumps assembly line was conducted. Proposed INEH simultaneously optimized all performance measures (Flow Time= 123.47min, Make-Span= 156.95min and Idle Time=1.67 min) while the traditional NEH variants only optimized single performance measure and ignoring the others. Performance of the proposed algorithm was compared with traditional NEH algorithm and its variants using TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), a MCDM technique. Results showed that proposed INEH outperformed rest of the NEH algorithms as TOPSIS ranked INEH first with the relative closeness of 97.3% while the NEH variant for flow time is worse algorithm with the relative closeness of 2.8%.
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The purpose of research is to model and correlate the laboratory rutting behavior of indigenous asphalt mixtures, prior to placing in the field. Extensive laboratory testing was carried out on thirty representative wearing course mixtures using two types of rutting performance tests i.e. CWTT (Cooper Wheel Tracking Tests), and APA (Asphalt Pavement Analyzer) tests. The mixture ranking is consistent for both laboratory performance tests at the tested temperature conditions of 40 and 50℃. Laboratory rutting prediction models have been developed by non-linear regression analysis technique. Significant independent variables involved in the model are temperature, number of passes in case of CWTT or number of cycles in case of APA tests, bitumen penetration value, and Flakiness index of coarse aggregates fraction. A strong relationship has been observed between measured and predicted values of rut depth in terms of R^2 value of 0.92 and 0.95 for CWTT and APA tests, respectively. A reasonable empirical quadratic function correlation (R^2 = 0.69) has been developed between rut depth of CWTT and rut depth in APA test.