Hydrodynamics of a floating body near a vertical wall is of interest in the field of coastal and offshore engineering. One reason for the need to understand this class of hydrodynamics is that lot of efforts have been devoted to developing the floating types of wave energy converters (WECs) that operate in nearshore or coastal zones from the purpose of reducing the emission of greenhouse gas. The other reason is that marine structures such as liquefied natural gas (LNG) shuttle carriers and very large floating structures (VLFS) are deployed near wharves or quay piers.

Rim Un Ryong, a researcher at the Faculty of Naval Architecture and Ocean Engineering, has studied the oscillating motion of an arbitrarily-shaped floating structure near a vertical wall under a linear wave by using a numerical method (i.e. BEM) with an exact NtD boundary condition.

His study results can be adopted to predict the motion responses and wave forces of an arbitrarily-shaped floating body in front of a vertical breakwater under a linear incident wave.

You can find details in his paper “Hydrodynamic Interaction Between a Linear Water Wave and a Floating Structure Near a Vertical Wall by Using an Exact Neumann-to-Dirichlet (NtD) Boundary Condition” in “Journal of The Institution of Engineers” (EI).

As environmental protection is becoming more and more serious, it is a pressing task to reduce industrial waste as well as to develop eco-friendly material that can be used for people’s living.

Ri Chol Jin, a section head at the Faculty of Earth Science and Technology, has investigated a synthesis method of 13X zeolite using fine granite dust (FGD) resulting from granite processing. Zeolite has good physio-chemical properties as an adsorbent, a cation exchanger, a molecular sieve and a catalyst and it is widely used as a selective scavenger of heavy metals from liquid effluents.

He selected and applied both the alkaline fusion method (770-830℃, 80min) and the hydrothermal process (95-100℃, 8-12h) to the synthesis of 13X zeolite.

What is important in the synthesis of zeolite by using alkaline fusion method is high sintering temperature. He lowered the sintering temperature from 1 300℃ to 800℃ by putting FGD into water and maintaining it for 5 minutes to remove crystalline quartz which has low reactivity.

In addition, it is important to find appropriate sintering temperature at which albite is decomposed more easily than kalifeldspar in FGD because 13X zeolite is chemically concerned with sodium (Na). For this, he calculated the reaction heats of kalifeldspar and albite at the temperature range of 770~830℃.

As a result, he proved that albite has the possibility to be dissolved thermodynamically more easily than kalifeldspar, but the difference between the heat effects of albite and kalifeldspar is not so significant according to the increase in temperature.

Eventually, he successfully synthesized 13X zeolite from FGD with low energy consumption and all other stone processing waste can be recycled by this method.

For more information, you can refer to his paper “Characteristics of flourite{111} surface with various terminations: A first-principles investigation” in “Results in Surfaces and Interfaces” (SCOPUS).

It is difficult to find out a suitable type for desired purpose among a large number of mechanisms that can be made by the spatial combination of links and joints. Here, quick calculation of correct mobility is the basic requirement for structural synthesis of parallel robot mechanisms.

Various methods reported in the literature for mobility calculation of closed loop mechanisms fall into two basic categories: an approach for mobility calculation based on setting up kinematic constraint equations and calculating their rank and an approach for finding formulae for quick calculation of mobility without constraint equations. Among them, the former is very useful.

Kim Yong Ho, a researcher at the Faculty of Mechanical Science and Technology, proposed a new method of calculating the mobility of parallel mechanisms by automatically generating velocity constraint equations and calculating the rank.

For automatic generation of kinematic constraint equations, he used formulae which enable automatic generation of the homogeneous transformation matrix and the Jacobian matrix of serial robot mechanisms.

He applied this method to CPM mechanism, Bennett mechanism and Bricard mechanism to validate its correctness, availability and prospectiveness.

For more information, please refer to his paper “Calculation of Correct Mobility of Special Mechanisms Based on Automatic Generation of Jacobian Matrix and Velocity Constraint Equation” in “Proceedings of KUTIC-2025”.