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.

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.

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.