Jo Jan 20, 2022
Kang Hwi Song, a researcher at Faculty of Electronic Engineering, and his research group have succeeded in manufacturing an Optical Passingtime Detector using infrared optical technology and Zigbee wireless communication and are expanding their achievements. This detector ensures speed measurement accuracy of 0.01s in a 30-meter section which is an important item in selecting and training reserve footballers.
As it is portable, it can be taken for camping drill and also be used in outdoor conditions with high illuminance as well as indoors. Moreover, it offers high stability and accuracy of speed measurement. The range of time measurement is 0~100s and the measurement accuracy is 0.01s.
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Jo Jan 18, 2022
Pak Thae Un, a section head at Faculty of Mining Engineering, studied and introduced a simultaneous blasting method by a high-voltage blaster whereby they could improve rock cutting property by enhancing the effects of simultaneous blasting in blasting operations.
They applied voltage of over 150v to each electric igniter linked to tens of detonators connected in series in the blasting circuit network with a high-voltage blaster generating high voltage impulse in order to cause discharge explosion effect, thus reducing the average detonation time to 4.7±1ms.
It resulted in the improvement in the effects of simultaneous blasting of blasting hole charges, which meant far more improvement in rock cutting property.
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Jo Jan 12, 2022
Many kinds of buoyant offshore structures such as wave energy converters (WECs) and weather buoys are being utilized to capture energy from the sea, protect coastal lines and study marine meteorology.
Since these structures often work for a long period of time, mooring systems are adopted to maintain their original positions, which is related to wave diffraction.
Rim Un Ryong, a researcher at Faculty of Shipbuilding and Ocean Engineering, has developed a novel DtN condition on a lateral cylindrical surface to solve three-dimensional wave diffraction by arbitrary-shaped floating bodies in water of finite depth.
First, he formulated wave diffraction with an artificial cylindrical boundary and derived a DtN condition on the artificial boundary.
Then, from the given boundary conditions, he solved wave problems numerically by implementing BEM and obtained the results for a chamfer box and their array.
The result showed that in the case of a single box, the plots for the amplitudes of heave and surge forces according to the incident wave direction have minimal values in the vicinity of the points in which the length of the box is integer times larger than the incident wavelength.
Besides, they witnessed more fluctuations for an array of the boxes than in the case of a single box, and the amplitude of surge force on the box became larger in the case of having other objects around it.
He presented his essay titled “Wave diffraction by floating bodies in water of finite depth using an exact DtN boundary condition” to SCI journals “Ocean Engineering”.
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Jo Jan 10, 2022
A research group with Sin Tong Ho, a researcher at Faculty of Mining Engineering, as a leader has developed and introduced a vertical shafting air classifier equipped with a rotor cage with high classification efficiency and an assistant air pipe that makes it possible to realize accurate classification as well as to control classification size in the processes of dry fine grinding or microfine grinding-classification of fireproof material, chemical material, abrasive material, etc.
They selected a reasonable structure and made a hydrodynamic analysis of the motion characters of mineral particles in the rotor cage. On this basis, they made an optimal design of structural and operational parameters and put them on a scientific basis so that they could ensure needed particle size distribution of powder products and high productivity.
The feed size of this classifier is less than 0.1mm and its classification size is 10~74㎛.
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