Jo Oct 9, 2026
In order to improve the academic skills of EFL (English as a foreign language) learners, due attention should be paid to teaching the exquisite principles of mind maps to put it into practice. Mind maps help facilitate mastery of contents such as logical grasping, integrating, systematizing and simplifying.
By using mind maps, they can facilitate their thinking and easily elaborate and present information. This is the process of understanding the contents of complicated system or structure, and at the same time, the process of learning the underlying principles. While preparing a presentation, they may encounter many difficulties in organizing the structure of summarized speech, which can be solved by using mind maps. By applying mind maps to presentation, they can acquire scientific research, problem-solving and critical thinking abilities. And they will also be well versed in correct formality and usage of academic speech, and correct mode and viewpoint of thinking such as logical development, demonstration, criticism and argument.
Kim Hye Won, a researcher at the Faculty of Foreign Languages, conducted an experimental research on the possibility of improving the EFL learners’ language skills and thinking abilities by applying mind mapping in the course of preparing and performing presentations, and proved its effectiveness.
She introduced the quasi-experimental design to two classes under study. She collected and analyzed data through tests and questionnaires to find out if there is any improvement. She found out that there was a remarkable difference between the two classes.
In conclusion, the results of her study show that mind maps are influential in improving EFL learners’ presentation abilities, i.e. language skills and thinking abilities.
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Jo Oct 8, 2026
A high-voltage electric heater (HVEH) is often used to manage fluctuations in renewable energy sources. The HVEH offers several advantages such as high electro-thermal power of thousands of kilowatts, low investment compared to its high thermal power and no need for transformers thanks to the direct supply from electric power net. However, it is difficult to predict thermal power capacity in the design step because it depends on the temperature, velocity and specific resistance of fluid.
In order to decrease the thermal power to hundreds of kilowatts and to guarantee operation safety, the whole electrical resistance of a heater should be increased. This can be realized through innovation of the internal structure of electric heater and some adjustment to its operation parameters because increasing only the electrical resistance of liquid is limited.
In order to solve this problem, Jang Ki Ho, a section head at the Faculty of Thermal Engineering, proposed HVEH of new structure, i.e. 10kV HVEH with PTF insulation tubes, and investigated the influence of fluid flow, temperature field and electrical field on thermal power in the design stage.
He presented a mathematical model representing the combination field of heat, fluid and electricity, and calculated it at a velocity of 0.1-0.5m/s and the temperature range of 20-80℃ with COMSOL. Then, he compared the predicted thermal power with a high-voltage electric heater under the identical operating conditions.
The results showed that the thermal power is acceptable below 650kW and the insulation tube is appropriate with a geometrical size of φ 0.17m×L 0.5m.
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Jo Oct 7, 2026
Ulmil Pavilion is a structure in Kyongsang-dong, Central District, Pyongyang, built on the site of northern command post in the inner wall of the Walled City of Pyongyang of Koguryo.
The name Ulmil is derived from a word meaning a flat upper hill.
Besides, according to legend, it was so named because in olden times Saint Ulmil came down from Heaven to have a good time there, and another legend runs that General Ulmil of Koguryo fought to defend the place.
The pavilion was first built in the mid-6th century as the northern command post of the keep of the Walled City of Pyongyang in the period of Koguryo and rebuilt in 1714.
Afterwards, it was repaired several times.
The embankment of the pavilion is about 11 metres high, so it looks like a very tall structure.
The pavilion towering above the embankment is also called “Sahojong” in a sense that it is situated in a picturesque place with an unobstructed, extensive view.
As it is decorated in the style of gorgeous morutanchong, it goes well with the surrounding natural environment.
The scene around the pavilion is among the eight famous scenes of Pyongyang, called “greeting the spring on Ulmil Pavilion”.
Ulmil Pavilion is associated with the Korean nation’s history of struggles against foreign aggressors, including Pyongyang people’s fight against Japanese invaders in the period of the Imjin Patriotic War (1592-1598).
The pavilion now serves as a resting site for working people and students visiting Moran Hill.
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Jo Oct 6, 2026
The process of sizing fine particulate material particles with different particle sizes is largely divided into sieving and sorting processes. Currently, a circular vibrating screen is used worldwide to reduce power consumption and improve classification efficiency of fine particles.
Circular vibrating screens are widely used in mining, building materials, chemical and pharmaceutical industries in the world today due to their advantages such as simple structure, small installation area, high reliability in operation and relatively high screening efficiency as compared to dry ultra-fine processing equipment.
The sieving and grading process of powder particles widely used in various sectors of the national economy also uses circular vibrating screens, air classifiers, spiral classifiers, water cyclones, etc. Although a circular vibrating screen has been used for the screening of particulate materials, it has a low throughput and does not use a multi-stage screen.
Ri Chol, a researcher at the Faculty of Mining Engineering, proposed a structural scheme of a circular vibrating screen with a two-stage screen surface for particle size separation of perlite powder particles in the process of crushing and grinding of perlite ore for the production of expanded perlite for soilless vegetable cultivation substrate, and optimized design parameters by simulating sieving operations using EDEM based on the kinetic analysis of screen surface.
The results showed that the screening efficiency was 98.87% when the eccentric mass was set to be 1kg and the phase angle between eccentric mass 45°.
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Jo Oct 5, 2026
October is a rich period when the weather gets cool, mountains and fields put on beautiful autumnal tints and plump ears of crops ripen in paddy and dry fields.
The seasonal subdivisions in October are Hallo and Sanggang.
Hallo means the time when cold dew begins to fall and it falls on October 8 this year.
Sanggang means the coming of frost and it falls on October 23 this year.
After Sanggang, the weather gets cold and the temperature difference between day and night gets bigger.
October is a busy season with harvesting and threshing of grain.
The Korean people have eaten various dishes that suit the seasonal characteristics of the October seasonal subdivisions.
Typical of them are soybean dishes and loach soup.
They also played different kinds of folk games.
Especially, children’s favourite games of hide-and-seek, hopscotch and tail-taking were spectacular.
Thus, the Korean people have created and carried on diligent and diverse working life and customs of diet, dressing and folk games suited to the seasonal characteristics of the period of Hallo and Sanggang from olden times.
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Jo Sep 29, 2026
Magnetotellurics (MT) is widely used for oil exploration. In MT, the time series of two telluric and three magnetic components of the magnetotelluric field are generally recorded at the ground surface in the Cartesian coordinate system. In practice, however, there are some difficult cases for setting two telluric lines orthogonally to record telluric components due to obstacles like roads, wetlands, rivers, cliffs, rice banks, buildings, etc. at a given MT site.
Kim Ji Yang, a researcher at the Faculty of Earth Science and Technology, proposed a method of converting telluric components recorded in non-orthogonal coordinate systems to those in orthogonal coordinate systems by means of mathematical coordinate transformation and verified its possibility and applicability through model and field tests.
This method makes it more convenient for MT field crews to choose site positions and set electric lines.
For more information, you can refer to his paper “Dealing with Non-orthogonally Measured Telluric Components in Magnetotellurics” in “Journal of Mathematical Methods in Engineering” (SCI).
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