Jo Mar 13, 2023
Sol Kyong Song (1237-1313), a doctor in Koryo, learnt medicine from his early age. When he became a doctor, he put his heart and soul into treatment and medical research.
He was well known at home and abroad as he was well versed in Koryo’s advanced clinical medicine of that time and excellent at treatment.
In 1285, he was invited to a neighbouring country to cure the king of the country from the disease that was accepted as incurable by many doctors invited there, thus showing the high standard of medical development of Koryo. After that, he was invited to the country several times more and demonstrated his excellent medical art.
Although he was in a favour with the King, Sol Kyong Song never wanted him to bestow any special benefits upon himself and what is more, he was indifferent to the living of his family. Instead, he devoted his all to treatment of patients and medical research to the last minute of his life.
Along with Ri Sang Ro, who lived in the second half of the twelfth century, Sol Kyong Song was known as one of the two great doctors of Koryo.
Sin Kwang Il, researcher at the Academy of Social Sciences
...
Jo Mar 10, 2023
Jang Rim Chol, a researcher at the Faculty of Mechanical Science and Technology, has developed a CNC engraving machine for cutting an EPS model.
The machine ensures high geometric accuracy and surface finish in cutting EPS models for lost form casting.
It consists of a computer, a control device, a mechanical system, an exhaust fan, etc.
What is new about it is the development of a spindle unit for EPS cutting and a rolling guide using ball bearings. Also, it has a rotary table that can change its rotating axis vertically and horizontally, so the machine offers satisfactory cutting of the EPS model of a spur gear whose diameter is 2 meters. The machine is also applicable to complex and large EPS models such as large bevel gears, housings and manikins.
...
Jo Mar 9, 2023
Koryo Songgyungwan was the supreme educational institution for training feudal government officials in Koryo.
“Songgyungwan” means “educational institution”.
In 992, Koryo feudal state established the supreme educational institution called Kukjagam. In 1298, it was renamed Songgyungam, and in 1308, it was given the name Songgyungwan. In 1356, it was given back the former name Kukjagam, and in 1362, it was named Songgyungwan again.
In those days, Songgyungwan admitted the offspring of aristocrats to teach Confucianism, and people of lower classes and commoners to teach handwriting, arithmetic, law, etc.
Years of learning depended on the subjects ― usually one to three years. Songgyungwan had competent scholars possessed of profound knowledge to give education on a number of subjects as well as tens of school buildings and welfare facilities.
Noting that Songgyungwan was the supreme educational establishment of Koryo feudal state, President
It is a great pride of the Korean nation to have the world’s oldest university with a history of 1 000 years.
Kim Son Yong, researcher at the Academy of Social Sciences
...
Jo Mar 6, 2023
Paek Hyon I, a researcher at the Faculty of Applied Mathematics, has created a new teaching method by combining lectures with experiments by a statistical analysis program in her subject “Mathematical Statistics”.
Statistical analysis program SPSS (Statistical Package for Social Science) gives a variety of statistical principles and methods, so it is accepted as a powerful tool for analyzing and processing an enormous amount of statistical data with rapidity and high scientific accuracy. With a powerful graphical function, it produces not only numerical results but also intuitive statistical plots after statistical analysis.
First, she outlines discussion points before letting students study the basics for statistical analysis. For example, she reminds them of the definition of random variable and its distribution, characteristics, regression and linear regression, central limit theorem, etc. Then, she leads them to finding out from reference books what stochastic concepts and principles are latent in statistical data from objects.
Next, she teaches briefly how to run SPSS with an emphasis on the correct analysis of the results displayed on the output window with some tables and plots, and gives some application examples of several statistical analysis methods on necessary occasions of lectures so that they can easily learn how to use it.
In a lesson on estimation and testing of regression coefficients, for example, she gives theoretical contents and shows how to estimate the regression coefficients of a regression model and find important factors by SPSS.
On this basis, she gives students tasks to obtain real data and analyze it in groups. In other words, she has them obtain real data, analyze it using SPSS and present essays on the analysis processes.
In this way, students can understand difficult mathematical statistics more easily and intuitively in connection with reality, and they can develop their program application abilities as well.
...
Jo Feb 28, 2023
Fast constructions from the Brownian motion and Brownian bridge are required in many applications such as Quasi-Monte Carlo simulations and statistical inferences on stochastic processes. A simple method for construction of discrete Brownian motion is a step-by-step method of computing the cumulative sum of i.i.d. normal variables.
The construction of N dimensional discrete Brownian motion (or a N-1 dimensional discrete Brownian bridge) that requires at most O(NlogN) floating point operations (flops) is called fast construction. Discrete Brownian motion can also be constructed using decompositions of its covariance matrix, and the method based on eigenvalue decomposition not only shows superior performances in many simulations over the step-by-step method but also becomes a fast construction. Usually the discrete Brownian bridge can be constructed from the discrete Brownian motion using the linear relationship between them. The inserting method using a decomposition of covariance matrix of discrete Brownian bridge gives another decomposition of covariance matrix for high dimensional discrete Brownian motion and it is very significant in Quasi-Monte Carlo simulations for financial derivatives.
Ri Sung Hyon, a section head at the Faculty of Applied Mathematics, has obtained eigenvalue decomposition of covariance matrix for discrete Brownian bridge and LDU (Lower-Diagonal-Upper) decompositions for covariance matrices of discrete Brownian motion and bridge newly and then proposed new fast construction methods on the basis of them. He has also proposed an inserting method for construction of discrete Brownian motion using eigenvalue decompositions which requires O(Nlog(logN)) flops.
The proposed new construction methods might be used effectively in simulations using Brownian motion and Brownian bridge. In addition, the construction algorithms would be used in analytical study for Brownian motion and Brownian bridge.
You can find more information about this in his paper “Decompositions of the Covariance Matrix of the Discrete Brownian Bridge: New Fast Constructions of Discrete Brownian Motions and Brownian Bridges” published in “American Journal of Applied Mathematics”.
...
© 2021 KumChaek University of Technology