Jo Nov 15, 2024
Real-time analysis in the chemical industry is becoming increasingly important as science and technology develops. The reality that real-time analysis is an essential tool for process automation and remote control is encouraging the introduction of new analytical systems more convenient and more accurate.
The establishment of analytical systems based on chemical image analysis has attracted great attention in the fields of process automation, agriculture, biology and medicine as well as analytical chemistry worldwide for its great prospect of application in process analysis.
The amount of nickel in plating solution is analyzed by photoelectric colorimetry, complex titration, gravimetry, polarography, etc. However, the chemical analysis of these nickel plating solutions is only possible in laboratories and limited in large-scale processes due to the manual work throughout the process.
Kim Yong Ok, a researcher at the Faculty of Chemical Engineering, has proposed a methodology for applying AI technology to chemical image analysis of nickel plating solutions.
First, she performed the preprocessing of solution images using dynamic contrast enhancement technique and constructed an extensible private function for capturing representative pixels from the preprocessed image.
Next, she developed a mobile application to establish a nickel analysis system in nickel plating solution by using deep learning. In particular, she built a model that underwent mechanical learning into Android applications so that all processes from photography to analysis could be carried out in a single program.
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Jo Nov 14, 2024
Recently, laser isotope separation has emerged as the most practical method for isotope separation compared to other separation methods, and research into it has been conducted intensively. There are several methods for laser separation, among which atomic vapor laser isotope separation is accepted as a promising method for both wide range of applications and possibility of expansion.
In this method, the first step of separation process is atom vapor and collimating. If the vapor source is heated to the target temperature under complete vacuum conditions, feed metal is melted to liquid state and starts evaporating. According to the temperature of vapor source, the rate of evaporation and vapor pressure of feed metal are controlled, which adjusts the atomic density of collimated atomic beam. At the laser pumping region, the atomic density of atomic beam is critical to the absorption cross section of laser beam.
Kang Chol Jin, a researcher in the General Assay Office, simulated the distribution of lithium vapor as a function of the length-to-diameter ratio of the source nozzle for laser isotope separation of lithium, and experimentally determined the atomic density distribution of lithium atomic beams in the collimated region.
It was found that when the heating temperature of the lithium vapor source was kept at 500℃, the atomic density near the nozzle central axis increased relatively rapidly with increase in the length-to-diameter ratio of the outlet nozzle, i.e., the atoms flying at an angle similar to the central axis of the tube flew almost linearly out of the nozzle.
According to the calculations, when the L/D value of the nozzle at 500℃ was 10 and the diffusion angle of the atomic beam was 10°, the collimation efficiency was above 46%.
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Jo Nov 12, 2024
Wind power generation system mainly consists of a wind power generator, a battery group to store generated electricity, a controller unit to transmit maximum power to load and an inverter system to supply power to AC load.
Generally, small wind power system is controlled by maximum power point tracking method, whereby the output current is controlled so that the wind power generation system can be operated at the maximum power point of the wind turbine regardless of the changing wind speed when the wind power generation system is operated independently. This method is suitable for systems where the rotational speed of the wind turbine varies sensitively with the change of wind speed due to the small inertia moment.
Hence, present papers introduce a method for maximum power output without a control circuit in a small wind power generation system. It is a driving method that approximates the active power curve of load to the maximum power curve of the wind turbine for maximum power operation by changing the generator’s electromotive force coefficient and the inductance of the two-winding generator. In wind power generation systems with two-winding generators of great inductance, however, the load power characteristics have saturation characteristics with respect to the number of turns. Therefore, the inductance alone is not enough to approximate the load power characteristics to the maximum power curve of wind turbines.
Kim Yong San, a researcher at the Faculty of Electrical Engineering, has solved scientific and technological problems arising in providing maximum power point operation of wind turbines using the two-winding generator and electromotive force coefficients in permanent magnet generators connected with wind turbines.
He theoretically analyzed how the power output of load depends on the generator’s electromotive force coefficient and the inductance of a two-winding generator, and proposed a method for determining the reasonable inductance and electromotive force coefficient that brings the generator’s effective power characteristics depending on the rotational speed closest to approach the maximum power curve of wind turbines.
Through the simulation analysis using MATLAB, he confirmed that the power characteristics of load could be operated near the maximum power curve of wind turbines.
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Jo Nov 8, 2024
Nowadays, according to constant changes in the manufacturing style of products, there arises a requirement for rearrangement of facilities. The way how facilities are laid out might cause bottleneck or not in production processes, and decides production efficiency. Therefore, reasonable layout of facilities is a very important problem in factories to be newly built or already built.
Generally, layout of facilities is based on mathematical modeling and optimized planning. However, its complexity fails to meet the requirements of developing modern production modes.
Paek Chol Yong, a researcher at the Faculty of Automation Engineering, has proposed a reasonable layout of facilities. Deciding that the layout of facilities in the machining workshop is a typical discrete event system, he conducted a simulation of the layout of existing facilities by using FlexSim to find its disadvantages and eliminate bottleneck phenomena.
Then, he applied the proposed layout method to a workshop. As a result, the productivity increased by 1.15 times and the production time decreased by 1.21 times as much as the original layout of facilities.
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Jo Nov 5, 2024
In order to realize automated and unmanned production processes, it is necessary to supervise and control the production process in real time, and check and evaluate the quality of products. Image processing units such as digital cameras are usually used to implement it. Recently, high-resolution cameras are used to improve the accuracy of data. The higher the resolution is, the bigger the amount of data is. Therefore, data transmission rate between computers and peripherals should be increased.
USB3.0 is a computer interface protocol that makes possible up to 5Gbps of data transmission by means of advanced techniques such as full-duplex transmission mode by multi channels, burst function using integrated packets and high-speed encoding technique by 8b/10b encoding, and its application technology has been widely studied for its good hardware connectivity and ease of use.
Ri Pyong Chol, a researcher at the Faculty of Information Science and Technology, has proposed a configuration and design of a USB high-speed transmission system that can achieve a USB3.0 data transmission rate of up to 3.2Gbps.
First, he combined a USB3.0 chip and Cyclone II FPGA to configure a high-speed data transmission system. Then, he programmed a firmware to set the data packet size and buffer size for maximum data transmission rate of the USB port. He also designed FPGA internal logic to increase the data transmission efficiency through the synchronous SlaveFIFO controller, the internal buffer, and the external I/O controller.
Finally, he measured the data transmission performance from the development system to the computer with a test program, and evaluated the efficiency of the proposed system design method.
He confirmed that the proposed method could ensure the data transmission rate of up to 3.2Gbps.
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Jo Oct 31, 2024
There are two main schemes of charging scheduling of a mobile charger (MC): periodic and on-demand. The latter schedules on-demand charging of a BS or MS, whose order is determined by temporal and spatial factors of request nodes. Recently, several intelligent on-demand charging scheduling schemes combined with multi-criteria have been proposed. Multi-criteria that conflict with each other, such as residual energy, distance to the MC, energy consumption rate, traffic relay load of charging request nodes, etc., play a key role in determining the charging priority of charging request nodes. However, which theory should be applied to determining the most suitable charging order of request nodes with such contradictory criteria is still a challenge that needs urgent solution.
Among the various multi-criteria decision making (MCDM) methods, the FAHP-TOPSIS method combined with fuzzy analytical hierarchy process (FAHP) and the technique for order preference by similarity to ideal solution (TOPSIS) are most widely used.
From the inspiration that an integrated MCDM in charging scheduling using multi-criteria could be effectively available throughout the whole charging scheduling process, Ri Man Gun, an institute head at the Faculty of Communication, has proposed a novel charging scheduling scheme based on an integrated FAHP-VWA-TOPSIS (iFVT).
Using an iFVT, he has also proposed a method of accurately calculating the relative weights of multi-criteria and determining the most suitable next-to-be-charged node by combinatorial evaluation of multi-criteria of request nodes
You can find the details in his paper published in “The 14th international Conference on Computing, Communication and Networking Technology (ICCCNT 2023)”.
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