Cavitation and corrosion on hydrodynamic components and systems reduces the operational efficiency. The use of wear resistant coatings have been studied as a solution to the problem of corrosion and cavitation in the ...
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A system for automatic detection of road damages is essential for logistics management. At the core of the system lies an algorithm for classification of damages. This work intends to establish such an algorithm. In t...
A system for automatic detection of road damages is essential for logistics management. At the core of the system lies an algorithm for classification of damages. This work intends to establish such an algorithm. In the current proposal, the algorithm receives data of the probe vehicle rate of rotations, extracts statistics descriptive from the data to produce a feature vector, and finally, feeds the vector to a simple-three-layer neural network to classify the damages. The types of damages are limited to four cases: normal, pothole, speed bump, and expansion joint. For the development, a probe vehicle is used to produce 400 empirical data involving those four damage cases. By using Monte Carlo approach, the established neural network model is evaluated. The results show that the approach is able to classify the cases with 85% accuracy. The study also finds that the rates of pitch and roll to be the determining factors.
Image magnification is one of the branches in digital image processing that is often required in various applications such as in the field of medicine, multimedia, and in satellite imagery. As technology grows, more a...
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In this research, the transient characteristics of a new type fuel metering system for aircraft turbofan engines using two types of pumps, a gear pump and a centrifugal pump, were studied by modelling and simulation. ...
In this research, the transient characteristics of a new type fuel metering system for aircraft turbofan engines using two types of pumps, a gear pump and a centrifugal pump, were studied by modelling and simulation. This new fuel metering system is capable of hydraulically unloading the operating state of each pump by the pump mode switching mechanism within the permissible range of the pump rotation speed and the fuel flow rate and it is possible to reduce the fuel temperature rise due to the pressure loss in the circuit in the operation region of the entire fuel system. In addition to this, by using a small centrifugal pump that can realize high discharge flow rate, it is possible to reduce weight compared to the conventional fuel system. However, when the pump mode is switched, unexpected fluctuation in the fuel flow rate can occur when a large change in the inlet pressure of the system occurs, the pressure control unit cannot follow the change, and the transient phenomenon cannot be suppressed. At this time, the pressure waveform generated at the time of changing the pump mode includes a high frequency component such that the pressure control unit, which plays a role of keeping the metering valve differential pressure constant, cannot follow up. Therefore, in this paper, we focused on the frequency of the pressure change waveform when the pump mode was changed and studied the model of the fuel system inlet pressure in the gear pump mode. Based on that model, we propose a method to reduce the frequency characteristics of the pressure change occurring at the time of pump mode change.
In this paper a new multi-objective approach for loop pairing in multi-input/multi-output processes is studied. Each controller structure of proposed input-output pairing is considered as a possible design concept. Un...
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The power system is a complex network having highly nonlinear dynamics. Being electrically interconnected power systems are vulnerable to instability due to the disturbances in any one portion of the system. Even low-...
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ISBN:
(纸本)9781538627570
The power system is a complex network having highly nonlinear dynamics. Being electrically interconnected power systems are vulnerable to instability due to the disturbances in any one portion of the system. Even low-frequency oscillations (LFOs) originated from small disturbances in any part of the network may cause the outage of the whole system. Power System Stabilizer (PSS) with optimal parameter settings is an efficient tool for the suppression of these oscillations. In this paper, a novel approach is proposed to tune lead-lag controller based PSS for a single machine infinite bus (SMIB) network by using backtracking search algorithm (BSA) to suppress LFOs through improvement of power system damping. The efficacy of BSA tuned PSS has been investigated by comparing the simulation results with fixed gain conventional PSS. In addition, the damping ratio and eigenvalues of the same network have been compared with genetic algorithm (GA) based tuned PSS.
Public street lighting consumes large energy for the public interest, but many street lights still do not use energy-saving technologies. In 2014, Provincial Government of DKI Jakarta operated 179,305 units of street ...
Public street lighting consumes large energy for the public interest, but many street lights still do not use energy-saving technologies. In 2014, Provincial Government of DKI Jakarta operated 179,305 units of street lights. Of the number of installed armature, 92 % of them or 166,441 units are HPS (High-Pressure Sodium) armatures which are inefficient. In 2016, the Provincial Government of DKI Jakarta cut down the energy used for street lighting, by implementing the programs of kWh-meter installation in every street lighting panel and use energy-saving lamps equipped with the smart system. The Provincial Government of DKI Jakarta is registered with 6,399 customer IDs in PLN (State Owned Electric Company), and gradually carried out the kWh Meter installation and changes to the contract. The program to use energy-saving lights done by replacing the HPS armature that is not energy efficient to LED armature which is known to be energy efficient. Until the end of 2016, the number of armatures that has been replaced was 89,417 units. The research results on 25 samples of PLN customer IDs and the replacement of 2,162 units armature, showed that the energy efficiency through kWh meter installation and armature replacement reduce the power consumption from 330,414 kWh to 71,278 kWh or by 78.43%. Generally, there was a decrease in the value of electricity bill compared to the before the replacement. The program of kWh-meter installations and replacement of the armature has a payback period of 2.66 years.
In article number 1903788, Michael C. Kolios, Scott S. H. Tsai, and co‐workers present new observations of microstreaming flows generated by cells under acoustic excitation. The observations suggest that the maximum ...
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In article number 1903788, Michael C. Kolios, Scott S. H. Tsai, and co‐workers present new observations of microstreaming flows generated by cells under acoustic excitation. The observations suggest that the maximum microstreaming flow velocity generated by a cell is highly dependent on the cell’s mechanical properties.
The formation of resonant photonic structures in porous silicon leverages the benefit of high surface area for improved molecular capture that is characteristic of porous materials with the advantage of high detection...
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Bacterial nanocellulose (BNC) has unique physical properties such as having high crystallinity, mechanical strength, purity, porosity, high water absorption capacity and biodegradable. This research aims to investigat...
Bacterial nanocellulose (BNC) has unique physical properties such as having high crystallinity, mechanical strength, purity, porosity, high water absorption capacity and biodegradable. This research aims to investigate the effect of high-pressure homogenizer (HPH) treatment cycle on the tensile strength and morphology of BNC membrane. This experiment begins from pineapple peel waste juice added with Acetobacter xylinum incubated for 14 days. The yielded pellicle then washed by distilled water then immersed in 1% NaOH for 24 h and pellicle well disintegrated using a high-speed blender, followed by homogenizing using HPH with repetition of 5 cycles at 150 bar. The solution was cast into a rectangular glass container and dried into an oven at 60 °C for 8 h. Results show that the tensile strength of BNC was 77.76 MPa and 75.97 MPa for membrane without HPH process and HPH process, respectively. The elastic modulus of BNC was16 GPa and 27.25 GPa for membrane without HPH process and HPH process, respectively. Morphological analysis using Scanning electron microscopy (SEM) showed the pores of BNC membrane prepared using HPH smaller than non-HPH. This means that the BNC membrane prepared by HPH was dense compared than Non-HPH membrane. Dense membrane caused a higher strength of the membrane.
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