Recent rapid development of mobile devices such as tablets and smartphones makes it possible to take a university course anywhere anytime and it has brought about a new type of learning; m-learning.

Downloading has been a common method for mobility. However, it is inevitable to download all data even when you need a certain part of a video clip or when you just need to go through it. This wastes communication cost and requires a user to wait until downloading is completed. In addition, it needs space for storing the downloaded data. Thus, streaming service of mobile education is a breakthrough in the world of education as a means of learning using Internet technology and mobile telecommunications devices.

Ri Ye Bok, a researcher at the Faculty of On-line Education, has proposed a SCORM-based package model for streaming service in distance education through mobile network.

The proposed model enables two kinds of service—downloading and streaming, using the same contents, thus not only guaranteeing the safety of data, but also saving memory space and providing convenience of management.

It can be easily implemented on various distance education sites as it converts learning contents into those for Android-based devices to provide several kinds of service in distance education systems based on the SCORM standard model.

Chonsangryolchabunyajido is an astronomical chart made in the late fourteenth century.

It dates back to 1395, based on the Koguryo’s astronomical chart carved on a stone.

The Koguryo’s astronomical chart (a table of constellations carved on a stone of about 2 meters in length and 1.2 meters in width) made between the late fifth century and the early sixth century shows 1 467 stars that were visible in the night sky of Pyongyang at that time. They are categorized in 282 constellations in a circle. The black ink copy of them on a piece of paper was used as base data for astronomical observation and calendar compilation.

Chonsangryolchabunyajido (122.8cm wide and 209.9cm long) was considered a very scientific and accurate astronomical chart in those days.

As one of the precious cultural legacies demonstrating the astronomical development of our country in the middle ages, it provides valuable information for the study of astronomical history.

Terbium belongs to the lanthanide or “rare earth elements (REE)” group of elements in the periodic table. However, rare earth elements are dispersed and they are not generally found concentrated as rare earth minerals (REM) in economically exploitable ore deposits. Terbium only occurs in trace quantities even in its ores. It is found in some minerals such as bastnaesite, monazite, xenotime, euxenite and gadolinite ores, but in low concentrations, on the order of 1%.

Terbium and its compounds are used as phosphors. Terbium phosphors give off a green light when struck by electrons. Phosphorescent terbium compounds are used in cathode ray tubes, light-emitting diodes, lasers, sensors, etc. Thus, terbium extraction processes need to be further studied and improved to include more economical and profitable methods.

Choe Kyong Mun, a researcher at the General Assay Office, has investigated the electrochemical behaviors of terbium in TbCl₃-1-ethyl-3-methyl-imidazolium tetrafluoroborate [EMIm]BF₄ electrolytes and TbCl₃-1-ethyl-3-methyl-imidazolium dicyanamide [EMIm]DCA.

X-ray diffraction analysis results of electrodeposits from TbCl₃-[EMIm]BF₄ electrolytes and TbCl₃-[EMIm]DCA electrolyte prove that metallic terbium is obtained.

For more information, please refer to his paper “Electrochemical behaviors of terbium from TbCl₃-EMImBF₄ and TbCl₃-EMImDCA ionic liquid electrolytes: a comparative study” in “Journal of Solid State Electrochemistry” (SCI).