Jo Sep 10, 2023
The earth’s orbit around the sun is divided into 24 with a central angle of 15°. The 24 points were given names to be 24 divisions of the year.
Each month has two divisions. Although the dates differ one or two days every year, the central angle, that is, the position of the earth stays the same.
The names of the 24 divisions reflect the experiences accumulated in the course of nature study and life from olden times and the simple desire of our ancestors quite accurately.
Even in present days the divisions give a lot of help in everyday life and organizing agricultural production.
The names Chunbun, Chubun, Haji and Tongji are related to the length of the day and night while Ripchun, Ripha, Ripchu and Riptong refer to the beginning of four seasons.
Sohan, Taehan, Choso, Taeso, etc. describe the degree of coldness and warmth. Usu, Kogu, Sosol and Taesol are associated with the period of rainfall and snowfall.
Kyongchip represents revival of all things after winter while Chongmyong refers to the clearness of the sky.
Soman and Mangjong are directly connected with the farming season.
Jo Sep 8, 2023
A research team led by Pak Kwang Hyok, a researcher at the Faculty of Distance Education, has conducted a study of GloVe (Global vector) for extracting the features of Korean.
While CBOW or skip-gram is the prediction task of a contextual word, GloVe is the presentation method by the number of co-appearance of words.
Skip-gram can reflect longer-distance information through skips between some words but this reveals a defect, that is, hard to reflect contextual information.
Therefore, Korean sentence corpora segmented by Byte Pair Encoder (BPE) are needed for extracting the features of Korean by means of GloVe.
The research team used an analysis engine based on the Long-Short Term Memory for BPE.
The research result showed that Korean feature extraction by GloVe was better in F-score estimation than that by CBOW or skip-gram.
This method can be applied to Korean sentence similarity evaluation for online exams and bibliographic search systems.
Jo Sep 5, 2023
The Mausoleum of King Tongmyong is a tomb of King Tongmyong, the founder of the Koguryo dynasty, situated in Ryongsan ri, Ryokpho District.
The mausoleum was brought to the present site by the movement of the capital of Koguryo to Pyongyang in the fifth century.
It was rebuilt in May, Juche 82 (1993). It stands magnificently as if it was demonstrating the might of Koguryo, which was once a great power, as the mausoleum of the founder king.
It is a stone structure covered with earth facing the south. It has a huge pile of earth, which is 11.5 metres high.
On the four 34-metre-long sides of the bottom part is a platform built of properly faced stones. Around the tomb, some graveside structures are set up on the 5-metre-wide pavement of riverside gravels.
Before the tomb, several structures stand in good order as they were in the days of the Koguryo dynasty.
On the top floor in front of the tomb are a stone table, a stone lantern and two stone sculptures of tiger. Along the right and left sides stand sculptured figures of civil and military officers and their horses. A pair of stone posts and a stone stove are also found there.
Erected in the east on the lower floor are “Monument to Sage King Tongmyong, Founder of the Koguryo Dynasty” and “Historical Monument to Sage King Tongmyong, Founder of the Koguryo Dynasty” written in Chinese character with explanations in Korean. In the west is a building for memorial service and in the south is a gate.
Under the care of the Workers’ Party of Korea, the Mausoleum of King Tongmyong was rebuilt wonderfully and it has been in good preservation. It is now making a positive contribution to educating our people in the national pride and dignity and patriotic spirit.
Jo Sep 4, 2023
A research team led by Chae Wi Song, a researcher at the Faculty of Distance Education, has developed an authentication system in which users are authenticated by analysis of keystroke dynamics.
Biometric authentication systems identify individuals by their physiological features (fingerprint, skin, retina, iris, etc.).
Each individual’s keystroke pattern is unique and a unique profile can be constructed by their typing speed, key press release timing, pressure applied, and finger positions on a keyboard.
The user authentication system based on this keystroke pattern is appealing for many reasons: simple and transparent authentication and no need for any extra equipment for feature capture.
The research team chose key press time and key release time among many keystroke patterns.
Key press time and key release time enable extraction of four features ― key hold time, key press latency, intervals between key press and release, and release and press. They used random forest algorithm for user authentication. The basic idea is to construct many trees using random vectors sampled from a data set.
This system guarantees fair online exams by automatically blocking several kinds of cheating attempts such as taking exams in place of examinees, keying in answers read by others, etc.
Jo Sep 1, 2023
National classic “Palhaego” is a book compiled by a realist scholar Ryu Tuk Gong (1748―?) in 1784.
Aiming to rectify the history of Palhae distorted by feudal historians and great-power chauvinists, Ryu Tuk Gong collected and sorted out a large number of books at home and abroad into “Palhaego” in one volume and in one book.
“Palhaego” is divided into several parts ― Kungo about the successive kings, Singo about central government officials, Jirigo about the territory, capital and local areas, Jikkwango about government offices and posts, Uijanggo about costumes of each rank, Mulsango about specialties, Kuksogo about letters sent to Japan, etc.
The book gives many-sided information about the foreign activities, territory, government post system, etc. What is particularly striking among them is it demonstrates that Palhae was a full-fledged sovereign state that succeeded to Koguryo.
The author wrote in the preface, “Where on earth is Tae from? He is surely from Koguryo. …The territory of Palhae right belongs to that of Koguryo.” He highlighted by means of the six letters sent by the kings of Palhae to Japanese kings that Palhae had been founded by the people of ruined Koguryo.
The book contains fairly detailed records indicative of the fact that Palhae was a sovereign state that exercised its sovereignty with dignity.
In addition, it repudiates the former view that Palhae had 60 provinces but proves that it had 62 provinces, and that the territory of Koryohuguk (a state founded by people of ruined Koguryo) belonged to that of Palhae.
In conclusion, “Palhaego” is a very important book that collected and catalogued all materials related to Palhae to rectify the history of Palhae for the first time in the middle ages of our country.
Jo Aug 30, 2023
Android-based oscilloscopes have been developed for research and educational purposes because they are able to acquire, transmit, display, and analyze any electrical signals since they are mobile and easy to operate.
Due to the speed limitation of wireless transmission channels, android oscilloscopes have some limited performances on several aspects such as bandwidth, waveform capturing rate (WCR), etc.
Kim Mun Hyok, a section head at the Faculty of Automation Engineering, has proposed a real-time lossless data compression scheme to solve a bottleneck of continuous data flow from a data acquisition device (DAQ) to a smartphone. This scheme consists of triggering a signal and encoding differences between waveforms (DBWs).
He also proposed an advanced structure of android bluetooth oscilloscope (ABO) to implement the proposed compression algorithm with field programmable gate array (FPGA)-based hardware and software.
To evaluate WCR improvement, he first analyzed relationship between WCR and compression ratio, and then, verified the compression efficiency by MATLAB simulations using various waveforms, such as simple sinusoidal, complex periodic, square, and chirp waveforms.
He finally studied the robustness of this instrument within the range of 0–15% noise amplitude and 0–2rad phase offset. All the experimental results showed that the proposed scheme can enhance WCR and at the same time it can also be applied to the wireless transmission fields collecting and displaying electrical waveforms.
If further information is needed, please refer to his paper “A Triggering-and-Encoding Lossless Compression Scheme for Waveform Capturing Rate Enhancement of Android Bluetooth Oscilloscope” in “IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT” (SCI).
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