Integrated Automation System for Hydropower Plants ...

Jo Sep 5, 2025

Wind or solar power generation systems are at an early stage of equipment or technical cycle life, but hydroelectric facilities are typically older and operate with a mismatched assortment of hardware and controls, which are not optimized to work as a unified system.

The changes of many parameters that affect the efficiency of a plant make it difficult for operators to fully optimize it. Thus, if hydropower plants are operated and maintained by operators, they may affect the efficiency of the generating equipment.

This is the reason why the operation and maintenance management system of hydroelectric power plants should have high control performance, be reliable and inexpensive, and minimize personal intervention.

Ri Kyong Hyok, a researcher at the Faculty of Electrical Engineering, has built a fieldbus control system by CAN and an SCADA system by Ethernet using the CAN interface function, Ethernet interface function and 485 interface function of a microcomputer, and integrated these systems to realize an automation system for hydroelectric power plants.

To improve real-time control, he installed two CAN networks, and further enhanced the reliability of the field bus system by checking the measurement accuracy of control parameters and monitoring the communication status of CAN bus in real time.

His research results have laid a foundation for implementing an integrated automation system using CAN bus in various fields of industry as well as in hydropower plants.

Jongum Gate on Moran Hill

Jo Sep 1, 2025

Jongum Gate is the southern gate of the northern castle of the Walled City of Pyongyang in the period of Koguryo. It is on Moran Hill in Pyongyang City.

First built in the mid-sixth century, it was repaired and reconstructed several times.

The present gatehouse, which was rebuilt in 1714 and burnt down during the past Fatherland Liberation War, was restored to the original state in 1959.

The embankment piled up with smoothly faced granite has a beautiful stable arched gateway, which is about 3 meters wide, 3.4 meters high and 6.35 meters long.

On the embankment is a gate house, which is three kans (7.36 meters) long and two kans (4.35 meters) wide.

Jongum Gate is a precious cultural relic that demonstrates the excellent architecture of the Korean ancestors and their patriotic spirit of bravely fighting against foreign aggressors.

3-D Design Method of Gear Cutting Tool Profile Base...

Jo Aug 29, 2025

Cutting tools have a decisive influence on the quality of machined parts and the efficiency of machining. Especially, the precision of cutting tools often leads to the precision of the gear class components.

There are two gear cutting methods; by forming and by generation. Because the gear cutting by forming has low machining accuracy and productivity, the gear cutting by generation is in common use. For gear generating, cutting tools such as a hob and a gear shaper cutter should be designed and manufactured precisely enough to increase the machining accuracy of gears.

The profile of a gear cutter is determined by the envelope equation of the instantaneous trajectory of the gear tooth profile. Therefore, the profile of the cutter can be determined only on the condition that the profile equation of the gear tooth to be machined is known. If the gear tooth profile is given as the measurement data or is a complex transcendental function, it is impossible to determine the profile of the cutter.

Choe Myong Chol, an institute head at the Faculty of Mechanical Science and Technology, has proposed a new method for 3D design of the toothed tool profile from the measurement data of a sample gear without any complex calculations in the way of reverse engineering.

This method can be applied to all generating cutters ranging from 2D to 3D tools.

For further details, please refer to his paper “3-D Design Method of the Gear Cutting Tool Profile Based on Reverse Engineering” in “Transactions of the Indian National Academy of Engineering” (SCI).