Jo Oct 1, 2021
Kim Song Chol, researcher in the Faculty of Mining Engineering proposed the mathematical model and solution that reflects the fluid flow in the dual-porosity reservoir with an elastic outer boundary to consider the flow characteristics.
In reality where oil, gas and water resources are developed, it is general that the dual-porosity reservoirs have the characteristics of both fissility and porosity.
In the preceding research, the percolation model is considered to be ideal boundary, and not to be elastic boundary that reflects real state.
In his paper he plotted the percolation model of dual-porosity reservoirs with elastic outer boundary and obtained the solution in Laplace space by using the Laplace inverse.
Then, by applying the numerical inverse Stehfest Laplace transformation, he found the solution in real space and analysed the characteristics of flowing period.
This proposed mathematical model can enhance the correctness of the well-test analysis of dual porosity reservoir.
His paper “Analyzing fluid flow characteristics in a dual-porosity reservoir with an elastic outer boundary” is carried on the SCI magazine “Acta Geophysica”.
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Jo Sep 29, 2021
Ju Kwang Su, Head of Lab, IT Institute has proposed anew algorithm to construct probabilistic visual cryptography scheme (k, n, 0, 1, 1)-PVCS without pixel expansion for threshold access structures based on deterministic visual cryptography schemes (DVCS).
To the visual cryptography schemes are belonged the probabilistic visual cryptography scheme (PVS), deterministic visual cryptography schemes (DVDS), and random grid visual cryptography schemes (RGVCS)
He analysed the relationship between the PVCS and RGVCS in the probabilistic schemes and proved that the two schemes boiled down in its configuration method and characteristics and newly formulated the relationship between PVCS and RGVCS.
And he constructed the off-line PVCS, based on the new DVCS expansion method and proposed PVCS configuration method which is simple in algorithm and safe in information.
His paper “Research on Novel Construction of Probabilistic Visual Cryptography Scheme (k, n, 0, 1, 1)-PVCS for Threshold Access Structures” was carried on SCI Magazine “Theoretical Computer Science”.
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Jo Sep 15, 2021
The contest was held from 3 to 13, September, 2021.
26 400 odd contestants from tens of countries and regions including our country, China, Russia and India took part in the contest, which was divided into three categories.
There were no challenge problems in this contest.
Therefore, 34 contestants took the 1st place, 3 students from Kim Chaek University of Technology belonged to category 1, they also succeeded in completing all of the assigned problems, thus taking the 1st place.
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Jo Sep 13, 2021
Kim Song Chol, researcher of the Faculty of Mining Engineering proposed a method to improve the accuracy of type curve for analyzing well-testing data.
It is the premise for the scientific development of the oil deposit to improve the accuracy of type curve for analyzing well-testing data.
The type curve for analyzing well-testing data, which can be obtained by solving the percolation differential equations, normally uses the Laplace transformation and numerical inverse.
In his paper, he combines the NILT based on infinite series with Levin convergence acceleration and determines necessary parameters through numerical experiments, thus improving accuracy and speed of numerical inverse Laplace transformation(NILT). And he compares the improved method with the Stehfest method using some functions such as trigonometric function.
And by applying the numerical inverse Laplace transformation and numerical inverse Stehfest Laplace transformation, he obtains and compares type curves for the analysis of well-testing data for the dual porosity reservoir respectively to indicate how that type curves plotted by the improved method are less in vibration.
His paper “Improved numerical inverse Laplace transformation to improve the accuracy of type curve for analyzing well-testing data” is carried on Sci magazine “Acta Geophysica”.
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Jo Sep 6, 2021
There has been an on-line National Public Presentation Meeting of Information Science and Technology under the joint auspices of the Central Committee of General Federation of Science and Technology of Korea and Education Commission from 17 to 19 of August.
This forum is focused on exchanging and propagandizing the achievements of educational information to provide students with constant education in such an emergency as worldwide healthcare crisis and natural calamities.
100 papers were put forth to the forum that drew teachers, researchers, postgraduate students, and students from several institutes including
The paper “Realization of off-line study-aid system for implementing the curriculum of undergraduate students during the emergency anti-epidemic period” presented by Ryu Chang Sik, head of lab, Faculty of Distance Education has been appraised as an excellent one for bringing about a practical advance in improving the educational contents and methods required by the world educational trend and the pedagogical requirements.
In addition to this, several papers of KUT have been estimated valuable.
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Jo Sep 5, 2021
Jang Kyong Wol, researcher of Robotics Institute presented a paper “A Tool Tilt Angle Calculation Method in 5-axis Flat-end Milling for Free Surface Machining” to EI Journal “International Journal of Industrial and Manufacturing Systems Engineering”.
Having analyzed the previous research results, she pointed out that CAD/CAM systems were not fully functioned in free surface machining because of the complex expressions.
Using quadric equation she succeeded in simply calculating the tool tilt angle and machining strip width produced in free surface machining with 5-axis flat-end milling. From this she proposed a calculation method to shorten the machining time by a great deal as well as to improve the effectiveness of machining.
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