OpenMP and MPI were preferred for parallel programming in the modes of shared memory and distributed memory, but now research has been focused on hybrid programming using both MPI and OpenMP and Apache Spark programming, which targets fast big data analysis.

Commonly, however, configuring a cluster environment requires more time than programming, and moreover, the difference between MPI-OpenMP of a parallel system using C language and Apache Spark of a distributed system using Java is one of the challenges to anyone who are not familiar with configuring Linux cluster as well as deploying Apache Hadoop stack.

Kim Ryo Chol, a section head at the Faculty of Information Science and Technology, proposed an integrated platform in which MPI-OpenMP and Spark parallel programming are both possible.

Virtual machines needed for parallel computation are provided by the private cloud based on OpenStack IaaS.

Applying the proposed method, he built an integrated platform for parallel programming, thus reducing the time for cluster environment configuration.

For more information, please refer to his paper “An Integrated Platform Architecture for MPI-OpenMP and Spark Parallel Programming on Cloud Environment” in “Proceedings of KUTIC-2025”.

The use of ozone gas started about a century ago and it has been used to purify water polluted by microorganisms. The chemistry of ozone in aqueous solutions is complex, and the direct reaction with molecular ozone and the indirect reaction with radicals generated when ozone is dissolved in water are considered for the process of water treatment with ozone. The direct and indirect reaction pathways of ozone generate different oxidation products and they are controlled by different kinetics.

Direct reaction of ozone has been quite well understood by previous researchers. The studies of ozone reactions and decomposition are still active, and most researchers are working on kinetics. The exact analysis of ozone reactions is still difficult due to very complex ozone reactions and insufficient information on reaction kinetic constants.

In theoretical studies of the UV-induced destruction of ozone layers in the earth's atmosphere, some researchers performed calculations of the stability of ozone-water vapor complex. The previous studies dealt with the reaction between molecular ozone and water vapor, but no first-principles studies have been carried out on the case of ozone gas dissolved in water. Therefore, first-principles study of ozone decomposition in water is necessary to improve the efficiency of water treatment by ozone.

Choe Un Hwa, a researcher at the Faculty of Physics, has determined reaction pathways for enhancing the efficiency of ozonation through first-principles considerations of ozone decomposition in water.

She newly defined the transition state that might be found during ozone decomposition in water and carried out a quantitative chemical calculation of ozone decomposition reactions in water by using the density functional method (DFT/6-31G*).

The results showed that the relative probability of the reaction to obtain H₂O₂ + O₂ among the four possible reactions between O₃ and H₂O in gas and water is high, which indicates that the improved oxidation of ozone can be used to improve ozonation efficiency.

Water is indispensable for human life and economic development, and therefore, water treatment is one of the primary technical processes essential for people’s living and the overall sectors of the national economy.

Desalination by electrosorption is a novel water treatment technique, which is a combination of electrochemical method and adsorption method of separation. It is employed to purify water by removing salts and other substances dissolved in water by using the adsorption of ions and charged particles in water when an electric field is applied to an electrode made of conductive adsorbent material.

The core of electrosorption technology is the selection of electrode material and the design of electrode structure. Carbon adsorbent materials such as activated carbon, activated carbon fibers, graphene, carbon nanotubes and carbon aerogels are used as electrode material.

Kim Chang Sok, a researcher at the School of Science and Engineering, calculated the desalination rate by electrosorption of activated carbon electrodes from the electrical double layer phenomena at the liquid interface and the characteristics of activated carbon, and investigated the main factors i.e. voltage, interelectrode distance, water flow rate and treatment time, influencing the desalination of groundwater by electrosorption using electrodes. On this basis, he determined the optimum electrosorption conditions.

When the voltage was 2V, the interelectrode distance 15mm, the water flow rate 4m³/(kg·h) and the time 45min, the electrical conductivity and the hardness decreased by 43.8% and 33.5%, respectively.

The results confirmed that water treatment by electrosorption is an effective method with high desalination and softening efficiency, low power consumption and no environmental pollution.