Jo Mar 22, 2022
Choe Song Bom, a section head at the Faculty of Information Science and Technology, has developed an image processor to obtain input images from hand-based shoe design images, and on the basis of it, he has continued to invent a new method of serial expansion and realize it in a serial expansion program.
This program consists of 3 parts: noise reduction, contour highlight, and serial expansion.
Its application reduced design hours from 10 to 3 and improved design accuracy from 90% to 98%.
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Jo Mar 21, 2022
In keeping with the actual conditions where communication equipment is on the increase in its kind and scale, the research team led by An Chong Il, a researcher at the Faculty of Information Science and Technology, has developed a network management system using a simple network management protocol that enables the integrated management of individual pieces of communication equipment.
Thanks to it, it became possible to manage different pieces of existing communication equipment in an integrated way and also to satisfactorily supervise and manage newly-added ones.
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Jo Mar 18, 2022
The research group led by Sim Jae Rim, a section head at the Faculty of Materials Science and Technology has succeeded in the research into an effective method of debinding in metal injection molding (MIM) products.
They put MIM products made with paraffin-based binder in a benzol-acetone solution to remove soluble binder before heating them to remove insoluble binder, thus increasing debinding rate by more than 5% and reducing the duration of debinding by more than 2 hours.
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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%.
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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.
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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.
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