• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.864-872
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• 2021

Objective : The aim of our study is to investigate the cytotoxic, antioxidant, and antimicrobial effects of newly synthesized boron compounds in U87MG glioblastoma cell treatment. Methods : We synthesized boron glycine monoester (BGM) and boron glycine diester (BGD) structures containing boron atoms and determined their cytotoxic activities on glioblastoma by the MTT method. The inhibitory concentration 50 (IC₅₀) value was calculated with GraphPad Prism 5.0 program. The IC₅₀ values were administered 48 hours on U87MG glioblastoma cell. Catalase (CAT), acid phosphatase (ACP) and alkaline phosphatase (ALP) enzyme activity, malondialdehyde (MDA), total glutathione (GSH), and total protein levels were detected using spectrophotometric methods. We determined the antimicrobial activities of BGM and BGD with the disc diffusion method. Results : After 48 hours of BGM and BGD application to U87MG glioblastoma cells, we found the IC₅₀ value as 6.6 mM and 26 mM, respectively. CAT and ACP enzyme activities were decreased in BGM and BGD groups. MDA which is a metabolite of lipid peroxidation was increased in both boron compounds groups. GSH level was reduced especially in BGD group. BGM and BGD have been found to be antimicrobial effects. Conclusion : Boron compounds, especially the BGM, can provide a new therapeutic approach for the treatment of glioblastoma with their anticancer, antioxidant, and antimicrobial effects.

• Journal of the Korean School Mathematics Society
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• v.24 no.3
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• pp.243-259
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• 2021

This study examines trends by school level, region, subject, and type centered on elementary schools when private education is perceived as a social problem due to the overheating of private education and its over-dependence. This study aims to provide a direction to ease the school mathematics education and meet the expectations of school mathematics education. As a result of this study, in mathematics subjects, the graph of private education expenses for mathematics subjects was not affected by the period and showed a somewhat consistent linear trend. In other words, we found that the private education cost of the mathematics subject was solid compared to other factors, and was not significantly affected by external variables, and was consistent. It is meaningful to examine the trends of private education costs in mathematics subjects with a comparison between the past and present and to grasp what factors and how they have changed and developed.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1769-1785
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• 2021

The Integral Pressurized Water Reactors (IPWRs) as the innovative advanced and generation-III + reactors are under study and developments in a lot of countries. This paper is aimed at the thermal hydraulic study of the hot and average fuel sub-channel in a Generation III + IPWR by loose external coupling to the neutronic simulation. The power produced in fuel pins is calculated by the neutronic simulation via MCNPX2.6 then fuel and coolant temperature changes along fuel sub-channels evaluated by computational fluid dynamic thermal hydraulic calculation through an iterative coupling. The relative power densities along the fuel pin in hot and average fuel sub-channel are calculated in sixteen equal divisions. The highest centerline temperature of the hottest and the average fuel pin are calculated as 633 K (359.85 ℃) and 596 K (322.85 ℃), respectively. The coolant enters the sub-channel with a temperature of 557.15 K (284 ℃) and leaves the hot sub-channel and the average sub-channel with a temperature of 596 K (322.85 ℃) and 579 K (305.85 ℃), respectively. It is shown that the spacer grids result in the enhancement of turbulence kinetic energy, convection heat transfer coefficient along the fuel sub-channels so that there is an increase in heat transfer coefficient about 40%. The local fuel pin temperature reduction in the place and downstream the space grids due to heat transfer coefficient enhancement is depicted via a graph through six iterations of neutronic and thermal hydraulic coupling calculations. Working in a low fuel temperature and keeping a significant gap below the melting point of fuel, make the IPWR as a safe type of generation -III + nuclear reactor.

• Journal of Information Science Theory and Practice
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• v.9 no.1
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• pp.24-34
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• 2021

The popularity of social networking sites (SNS) has facilitated communication between users. The usage of SNS helps users in their daily life in various ways such as sharing of opinions, keeping in touch with old friends, making new friends, and getting information. However, some users misuse SNS to belittle or hurt others using profanities, which is typical in cyberbullying incidents. Thus, in this study, we aim to identify profane words from the ASKfm corpus to analyze the profane word distribution across four different roles involved in cyberbullying based on lexicon dictionary. These four roles are: harasser, victim, bystander that assists the bully, and bystander that defends the victim. Evaluation in this study focused on occurrences of the profane word for each role from the corpus. The top 10 common words used in the corpus are also identified and represented in a graph. Results from the analysis show that these four roles used profane words in their conversation with different weightage and distribution, even though the profane words used are mostly similar. The harasser is the first ranked that used profane words in the conversation compared to other roles. The results can be further explored and considered as a potential feature in a cyberbullying detection model using a machine learning approach. Results in this work will contribute to formulate the suitable representation. It is also useful in modeling a cyberbullying detection model based on the identification of profane word distribution across different cyberbullying roles in social networks for future works.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.155-161
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• 2021

Gesture recognition analytics through a camera in real time have been widely studied in recent years. Since a small number of features from human joints are extracted, low accuracy of classifying models is get in conventional gesture recognition studies. In this paper, CBAM (Convolutional Block Attention Module) with high accuracy for classifying images is proposed as a classification model and algorithm calculating the angle of joints depending on actions is presented to solve the issues. Employing five exercise gestures images from the fitness posture images provided by AI Hub, the images are applied to the classification model. Important 8-joint angles information for classifying the exercise gestures is extracted from the images by using MediaPipe, a graph-based framework provided by Google. Setting the features as input of the classification model, the classification model is learned. From the simulation results, it is confirmed that the exercise gestures are classified with high accuracy in the proposed model.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.1-12
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• 2021

An objective expert discrimination scheme is needed for finding researchers who have insight and knowledge about a particular field of research. There are two types of expert discrimination schemes such as a citation graph based method and a formula based method. In this paper, we propose an efficient expert discrimination scheme considering various characteristics that have not been considered in the existing formula based methods. In order to discriminate the expertise of researchers, we present six expertise indices such as quality, productivity, contributiveness, recentness, accuracy, and durability. We also consider the number of social citations to apply the characteristics of academic search sites. Finally, we conduct various experiments to prove the validity and feasibility of the proposed scheme.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.7
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• pp.263-270
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• 2021

Reinforcement learning(RL) is the method to find an optimal policy through training. and it is one of popular methods for solving lifesaving and disaster response problems effectively. However, the conventional reinforcement learning method for disaster response utilizes either simple environment such as. grid and graph or a self-developed environment that are hard to verify the practical effectiveness. In this paper, we propose the design of a disaster response RL environment which utilizes the detailed property information of the disaster simulation in order to utilize the reinforcement learning method in the real world. For the RL environment, we design and build the reinforcement learning communication as well as the interface between the RL agent and the disaster simulation. Also, we apply the dimension reduction method for converting non-image feature vectors into image format which is effectively utilized with convolution layer to utilize the high-dimensional and detailed property of the disaster simulation. To verify the effectiveness of our proposed method, we conducted empirical evaluations and it shows that our proposed method outperformed conventional methods in the building fire damage.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.365-375
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• 2019

A PLC (Programmable Logic Controller) is a highly-reliable industrial digital computer which supports real-time embedded control applications for safety-critical control systems. Real-time operating systems such as uC/OS have been used for PLCs and must meet real-time constraints. As PLCs have been widely used for industrial control systems and connected to the Internet, they have been becoming a main target of cyberattacks. In this paper, we propose an execution code sanitizer to enhance the security of PLC systems. The proposed sanitizer analyzes PLC programs developed by an IDE before downloading the program to a target PLC, and mitigates security vulnerabilities of the program. Our sanitizer can detect vulnerable function calls and illegal memory accesses in development of PLC programs using a database of vulnerable functions as well as the other database of code patterns related to pointer misuses. Based on these DBs, it detects and removes abnormal use patterns of pointer variables and existence of vulnerable functions shown in the call graph of the target executable code. We have implemented the proposed technique and verified its effectiveness through experiments.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.383-389
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• 2018

Recently, it has been reported that water pollution due to non-point pollutants continues. Studies have been actively carried out to prevent such non-point pollutants from flowing into the water system and to prevent water pollution. In this study, to evaluate the adequate design of the LID facilities the rainfall corresponding to 80% of the cumulative rainfall of Yongin city was applied to an SA / CA graph obtained from the analysis of monitoring results of the vegetation type LID facility. As a result, the appropriate SA/CA ratio was 0.6% for stormwater sustain efficiency 80% and the appropriate SA/CA ratio was 0.5% for TSS removal efficiency 80%. The appropriate SA/CA ratio of the vegetation type LID proposed in this study can be used as a basis. for the future vegetation type LID design. If more data of vegetation type LID are added through continuous research, it will be more accurate.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.105-113
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• 2019

The purpose of this study is to analyze cyber security risk modeling of critical infrastructure, draw out limitations and improvement measures. This paper analyzed cyber security risk modeling of national critical infrastructure like as electricity sector, nuclear power plant, SCADA. This paper analyzed the 26 precedent research cases of risk modeling in electricity sector, nuclear power plant, SCADA. The latest Critical Infrastructure is digitalized and has a windows operating system. Critical Infrastructure should be operated at all times, it is not possible to patch a vulnerability even though find vulnerability. This paper suggest the advanced cyber security modeling characteristic during the life cycle of the critical infrastructure and can be prevented.