Jo Mar 17, 2022
The research team led by Kim Sung Nam, an institute head at the Faculty of Information Science and Technology, has developed a DNA computing simulation program to perform parallel computations on a personal computer by applying a DNA encoding process, a branch of biochemistry, to the optimum solution of intellectual problems.
The program consists of 3 parts: monkey-banana problems, TSP problems and word association problems.
This program is able to generate all possible paths and examine the possibility of optimization at the same time in parallel by simulating the DNA computing programmatically, in contrast to traditional optimal path-finding methods that generate all possible paths and then find one among them by examining conditions one by one.
The average time of solving problems is about 20s (Core i3) and the accuracy reaches 95%.
...
Jo Mar 16, 2022
Han Myong U, a researcher at the Faculty of Communication, has been making achievements by employing a self-designing experimental method in experimental education whereby students can design the whole process from the idea of a device to its manufacture and do measuring experiments by themselves.
The subject “electroacoustic engineering” is the study on principles and methods to turn electrical energy into acoustic energy and vice versa, and also to implement its acoustic systems.
In the past experimental teachings, students failed to have a good understanding of the overall experimental process as they followed the fixed orders and methods, and also they revealed a lack of skills in analysing why the experimental results were different from theories and in working out how to deal with it due to the fact that almost all results were apparent and predictable.
In order to fix these problems, he has applied a self-designing experimental teaching method, whereby students can design by themselves the overall process from the plan for device-manufacturing to its implementation and then do measuring experiments, to experimental teachings, thus achieving a series of successes.
First, he gave experimental tasks to students for designing the most adaptable experimental instruments and measuring frequencies in their own way in parallel with recollecting carefully what they already learnt.
The tasks were supposed to have various choices of experimental objects and various plans of experimental processes, and to have different results according to their own plans and performances.
For example, during the experiment on the evaluation of the directivity characteristics of speakers, the tasks such as “Please select the worst and best speakers in terms of cross modulation and compare them.” and “Please select the speaker with the narrowest directivity and the one with steady directivity in a high-frequency band and compare them.” can lead the students to acquire the several characteristics of speakers and their measuring principles that are being widely considered in reality.
Through these tasks, the students are able to acquire more profound knowledge about the characteristics of several kinds of speakers by revising sufficiently what they have already learnt ranging from the selection of available speakers and microphones for experiments to the selection of measuring frequencies and the interval of measuring angles for clear comparison and analysis as well as by reading references intensively.
Second, he has motivated students to design by themselves the experimental processes before conducting simulations with simulation tools in order to compare and analyze the results.
After making clear the overall plan for the experimental process, they can go deep into a detailed study in order to obtain as much correct measurement data as possible within the limited time.
For example, in an experiment on the directivity characteristics of a speaker, they can make a detailed design of how to determine the space of experimental tables, how to measure the next frequency after rotating them by 180 degrees, whether to keep measuring after returning to the initial coordinate, and whether to do all measuring experiments on several frequencies at the same angle, and then prepare for the experiment according to the design.
After that, they can decide whether or not the simulation methods and elements they selected are suitable and their measuring frequencies are most reasonable.
For the simulation of speakers, students commonly use simulation software for directivity. In this case, they conduct a dynamic simulation based on the detailed geometrical sizes and values of speakers selected by them.
While analysing the correctness of the plan they selected and the reasons for false choice, they get to study continuously how to make a simulation closer to the reality by confirming the experimental plans they have made and changing the experimental design to a certain degree if necessary.
Thus, he was able to enhance students’ cognition in class by building up their creative thinking ability, and additionally to equip them with practical and technical skills for designing, simulating and analyzing the electrical acoustic instruments on their own.
...
Jo Mar 14, 2022
Ko Thae Hwan, a researcher at the Faculty of Communication, has combined special purpose development devices and application programs in his lectures so that the students could understand easily what they learnt and apply it to practice actively.
In order to make students study with active attitudes as a seeker after new knowledge instead of receiving it with passive attitudes, it is necessary to make a proper combination of traditional and progressive teaching methods drawing on traditional ones.
This subject deals with several signal processing principles for amplification, filtering, generation, detection, operation of electric and physical signals, and the determination of parameters, system design and application methods. As the subject has a large proportion of theoretical lectures and touches a lot of things based on mathematical principles, it is important to provide students with as many chances of practice as possible to confirm the relationship between basic principles and practical application.
In the past, students used to learn the basic principles of a filter only in a theoretical way and to design it to simulate in experiments. Therefore, they had to analyze the operating characteristics of a filter only in a simulation environment, but could not see how it worked in reality, which resulted in low cognition effect.
For instance, since teaching on basic mathematical principles accounted for nearly 70% of the whole lecture, students faced an absolute limit of time to associate what they were learning with issues arising in engineering practice. In addition, no combination of simulation tools and devices for the analysis of the operation of a filter left them with a poor grip of the real characteristics even after lectures.
To solve such problems, he, first of all, combined a DSP development device and MATLAB in the lecture.
A notable difference from previous lectures is the frequent utilization of MATLAB.
When teaching on the approximation of an ideal low pass filter, he combined the theoretical calculation of the transfer function and the order and pole of a filter with MATLAB simulation so that they could compare the amplitude-frequency and phase-frequency characteristics under various design conditions, therefore ensuring maximum teaching density and helping them master the theories and methods of designing a digital filter at the same time. In this way, he did not focus on mathematical analysis or results, but on directing them to get the physical meaning of the design and the calculation process through simulation, which made them think about the corresponding simulation tools whenever they came across certain expressions.
Second, making an organic link of a DSP development device and MATLAB in the subject design, he put a simulation environment and the manufacture of a real filter into one.
Although the utilization of MATLAB certainly does help students have a good understanding of the design of a digital filter, it is not able to stimulate their creative power to the full. For this reason, he provided with a DSP development device for them to do experiments on and analyze the operation of a filter in the communication system.
For example, he gave every student different assignments so that they could compare the results from MATLAB and the DSP development device and draw conclusions on their own. Thus, they were able to find and correct their design mistakes so as to be well aware of the methods of design and implementation.
...
Jo Mar 11, 2022
Yu Chol Min, a researcher at the Faculty of Metal Engineering, has been using anecdotes and practical data in physical chemistry to help his students have a better understanding of concepts and formulae given in the lectures. As a result, they have been able to grasp the main points of his lectures and to improve their practical abilities.
Physical chemistry is a subject which deals with the relation between physical and chemical phenomena occurring in metallurgical processes, and its contents are mostly related to abstraction and theory. For this reason, if the lecture is focused on explanation of theories, derivation of formulas or calculation, students will find it difficult to have a notion of what they are learning and it may lead to the decrease in their enthusiasm for study.
Therefore, he decided to invent some methods to stimulate students’ interest and enthusiasm and to provide them with a vivid notion.
To start with, he used the method of telling anecdotes about famous scientists to improve the understanding of concepts and formulas given in the lectures.
Even a single concept, a law or a formula came into being through the efforts of many scientists and it involved corresponding anecdotes.
If students are told certain anecdotes related to a notion or a formula, they can get to know about the history and mysterious background of them and understand them more easily.
For instance, he used the following anecdote in the lecture on the second law of thermodynamics.
The efficiency of the steam engine made by Watt in 1770s was less than 10% and it wasted a large amount of heat energy. So scientists tried to make a perpetual machine which would convert the whole amount of heat energy provided by a single heat source to completely different kind of energy.
“Zero motor” which a scientist attempted to design is a typical example. According to research, if the heat diffused in the process of lowering the temperature of about 109km3 of the sea water on the earth by 0.25℃ was converted into energy, 1015kW of electrical energy would be produced, which is said to be quite enough for the whole world to use for as long as a thousand years.
He wondered if he could get mechanical energy from the steam released when liquid ammonia in a cylinder was gasified by such a huge amount of heat energy, and liquefy it back. Then, he was planning to make a motor which produces energy constantly through this cyclic process. However, his idea turned out to impossible and his effort was in vain since gasified ammonia can never be liquefied on its own.
In addition to him, many scientists attempted to make a perpetual machine for many years, but they all failed. In the meantime, an idea came into their minds. They wondered if the impossibility of making a perpetual machine might serve as a kind of law that explains the natural world. That was formulated as the second law of thermodynamics in the middle of the 19th century.
Such a historical fact related to a perpetual machine stimulated students’ interest in the second law of thermodynamics so they could have a scientific understanding of what a perpetual machine was and why it was impossible to make it.
Next, he led students to grasp the gist of the lecture by themselves and to improve their practical abilities by giving a scientific solution to the problems they usually come across in their daily life.
The examples closely connected to new knowledge and often seen in daily lives could improve their faculties of inquiry and creation and make them realize the significance and value of their knowledge by leading them to the world of physical chemistry.
We can take the lecture on the kinetics of heterogeneous reaction as an example.
Explaining the kinetic difference between homogeneous and heterogeneous reactions like solid-gas, solid-liquid and solid-solid, he presented a question, “Why do they burn powdered coal instead of lump coal in the boilers at thermal power plants?”. Then the students answered that the combustion of powdered coal is faster than that of lump coal because the surface area of powdered coal is larger.
He continued explaining that powdered coal flew about in rotary kilns, which resulted in a great loss, and that it raised the issue of forming it into small grains. Then he set forth a question for this and led them to its solution.
Therefore, the students could have chances to apply what they had learnt to practice and try harder to acquire more knowledge.
...
Jo Mar 9, 2022
Jong Song Dae, a lecturer at the Faculty of Social Sciences, has been enhancing cognition efficiency by telling funny and persuasive short stories at appropriate time in his lecture.
Witty humour that teaches you something meaningful along with laughter with great persuasive power has greater influence than any kind of wordy speeches or writings.
In psychology lectures that help students to do successful work with people on the basis of the scientific understanding of various psychological phenomena and laws formed among people, he applied humour effectively to enable them to understand what they learnt in a plain way and to raise their faculties of thinking and eloquence.
Firstly, he found as many short stories as possible helpful to develop students’ thinking and told them at appropriate time, thus raising the level of popularity. In other words, he found good examples relevant to the content of the lecture and applied them.
For instance, “Baby’s job” was told in the lecture on the process of formation and development of human psychology, and “Did the cocks celebrate the New Year’s Day in such cold weather?” in the lecture on a desire.
He also collected a lot of short stories for the development of thinking and set occasions for appropriate application.
For example, he chose “The latest tooth” and “An expert in poultry” for types of thinking, “Oral thanks” for reaction of feelings, “Repeated rudeness” for types of hobbies and tastes, and “Pride of a squad leader” for types of human relationship.
Secondly, he raised cognition efficiency by making students analyze stories by themselves.
For example, in order to help them to have an understanding on their own of the formation and development of psychology in the childhood, he started with telling “I need more fingers.”.
It goes as follows.
A mother was teaching arithmetic to her 5-year-old son.
Mother: How much is eight plus five?
Son: Mum, I need more fingers…
He let students analyze it in their own ways.
Their argument produced several analyses: the child was not able to count it because he had only 10 fingers, the child was unable to count it because he had not learnt to count numbers over 10, that is, he did not know that he could spread out his fingers for continuous counting after counting to 10, etc.
As a result, they could grasp the gist of the lecture easily which said that in the childhood thinking is restricted to those that have immediate relation to the objects they can perceive and imagine at the moment and that object motion-centred thinking develops into intuitive depictive thinking.
As mentioned above, the employment of humour made it easier and faster for students to understand what they learnt, and heightened the faculties for its practical application to the life.
...
Jo Mar 7, 2022
Kim Hwang Won was a well-known poet in Koryo. Touring the scenic spots in our country, he composed a number of poems about the beautiful scenery.
One summer he climbed the Moran Hill to the Pubyok Pavilion overlooking the beautiful mountains and rivers in Pyongyang. Gazing at the Taedong River of translucent blue skirting round the Chongryu Cliff and the Walled City of Pyongyang, and East Pyongyang spread out endlessly in mist, he just stood still for a long while, enchanted by the magnificent view.
(I have never seen such wonderful scenery before!)
He was lost in appreciating the beauty of the landscape.
He was maturing his idea of a poem for a good while with his arm on the pillar until finally he started driving his writing brush catching the eyes of a crowd of people surrounding him.
Even though he wrote down a few lines at a go without difficulty, he was prevented from carrying on.
After some minutes of looking down from the pavilion with the brush in his hand, he made another attempt. However, he found it more and more difficult to continue with the poem. When he looked far down at the translucent blue waters of the Taedong River from the Pubyok Pavilion, he felt as if he was standing on the pavilion in “the Palace of the Sea God”, which sprang high above the sea, and looking over the Tongdaewon Field veiled in mist made him feel like standing on the balcony of “the Palace in Heaven” floating over the clouds. He found his talent was far from the charming scenery that struck him with a fresh impression everytime.
All of a sudden, he broke the stem of his brush and wept smacking his hand down on to the floor.
“Ah, I am not talented enough to depict the beauty of Pyongyang!”
Lamenting over the lack of his talent, he continued weeping until late at night before he left there. Later, the people in Pyongyang kept his unfinished two-line poem hanging on the pillar of the pavilion and at present it is seen on the column of the Ryongwang Pavilion. That is Kim Hwang Won’s unfinished poem “On the Pubyok Pavilion”.
The reason why they hung his poem on the pillar of the Pubyok Pavilion lies in the fact that they wanted to be proud of the beauty of Pyongyang generation after generation, which even a famous poet could not find enough poetic words to depict as well as the fact that it was well-written.
...
