• 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.

• Convergence Security Journal
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• v.22 no.5
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• pp.3-9
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• 2022

Recently, in order to build a cyber physical system(CPS) that is a technology related to the 4th industry, the construction of the virtual control system for physical model and control circuit simulation is increasingly required in various industries. It takes a lot of time and money to convert documents that are not electronically documented through direct input. For this, it is very important to digitize a large number of drawings that have already been printed through object recognition using artificial intelligence. In this paper, in order to accurately recognize objects in drawings and to utilize them in various applications, a recognition technique using artificial intelligence by analyzing the characteristics of objects in drawing was proposed. In order to improve the performance of object recognition, each object was recognized and then an intermediate file storing the information was created. And the recognition rate of the next recognition target was improved by deleting the recognition result from the drawing. In addition, the recognition result was stored as a standardized format document so that it could be utilized in various fields of the control system. The excellent performance of the technique proposed in this paper was confirmed through the experiments.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.593-598
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• 2014

To solve the labor shortage of skilled workers, the ship building industry needs the automation and mechanization. Especially, compared with other process, handrail manufacturing process of ship building falls behind the automation. In this paper, we designed and implemented a flat-iron automation system using computer convergence technology that can be used in the production of handrails in shipbuilding. The system's machine part was designed by considering the efficiency, productivity, and stability of the cutting process, and checked the stability of the structure using CATIA and ANSYS. The system's control part was used the PCNC controller to provide openness and scalability. And the part was made for system control and monitoring the system through screen manipulation with touch-screen form. A flat-iron automatic system was developed by converging the mechanics, electronics and computer technology and it will contribute to improve the productivity of the industrial system.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.742-748
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• 2009

Zigbee wireless communication technology has features which are low cost, low power and coping ability against a high delay time when the automatic wireless system is manufactured. Therefore, in this paper, we research a method improving the data transmission reliability of the industrial equipment control and management system using zigbee wireless communication technology. we used a convolutional code with code rate R=1/2, constraint K=5 and generation polynomial constant g1=(10111) and g2=(10011) as a reliability method. From the transmission simulation at LOS environment, we are able to predict the transmission error performance according to the distance difference. Furthermore, At the PER performance analysis, we can get the result that this system reliability with convolutional code is improved about 5 times than the existing system. From these results, we can prove that the convolutional code is the solution to improve the system reliability of the industrial equipment control and management system using zigbee wireless communication technology.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.6
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• pp.9-16
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• 2013

Bio-impedance measurement system(BMS) is non-invasive and easy to implement a measurement method that allows determining the water content of a patient. The measurement conditions, the hardware specifications and the configurations of BMS devices must be well chosen in order to get correct and reproducible results. BMS was then conducted for the limbs and the thoracic using a lock-in amplifier and LabView control system with a frequency range of 1kHz-100kHz. From both the measurement data and the simulation results, we verified that the parameters in the proposed equivalent model and the trend of impedance variation according to the multi-frequency of applied current source are similar to those of human body. We believe that the real-time BMS developed in this study is highly reliable and applicable to the research on the clinical characteristics of the human being's impedance.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.171-177
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• 2020

Under the influence of the Fourth Industrial Revolution, there are many tries to promote productivity enhancement and competitiveness by adapting smart farm technology that converges ICT technologies in agriculture. This smart farming technology is emerging as a new paradigm for future growth in agriculture. The development of real-time cultivation environment monitoring and automatic control system is needed to implement smart farm. Furthermore, the development of intelligent system that manages cultivation environment using monitoring data of the growth of crops is required. In this paper, a fast and efficient development method for implementing a cloud-based smart farm management system using a highly compatible and scalable web platform is proposed. It was verified that the proposed method using the web platform is effective and stable system implementation through the operation of the actual implementation system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.83-89
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• 2021

With the recent development of information and communication technology, there have been many attempts to apply various IT technologies in the railway field. Until now, the safety control system has been installed at the site and operated using actual data, but there is a problem that it is difficult to verify the function of the railway safety control system in that no accidents occur in real situations. In this study, accident data is generated randomly to verify that the safety control system is functioning properly, and to this end, simulation data is prepared according to the simulator, accident scenario and scenario. Real-time railway safety monitoring system collects and transmits data from interface devices to common protocol called DDS.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.146-160
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• 2023

Purpose: The construction industry is a complex mechanism in which multiple processes are carried out at the same time, and the frequency and severity of accidents account for a higher proportion than other industries, and the accident fatality rate also accounts for more than 50% of all industries. In order to reduce such accidents, the government's disaster investigation method analyzes the limitations from the system safety point of view and proposes improvement plans. Method: The main contents of the government's serious accident investigation were identified, and the effectiveness/adequacy was analyzed from the system safety point of view. Result: Disaster investigation and analysis techniques tailored to violations and compliance were limited in providing fundamental solutions, and alternatives for accident prevention were possible for each component of the system when safety constraints, controls, and hierarchical interactions were combined. Conclusion: When combining the disaster investigation and analysis method from the current accident analysis method from the perspective of system safety, it is possible to identify the problems of interaction by class and communication process, so it is possible to suggest alternatives to prevent accidents from an integrated perspective.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1379-1386
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• 2005

For efficient welding it is necessary to maintain stability of the welding process and control the shape of the welding bead. The welding quality can be controlled by monitoring important parameters, such as, the Arc Voltage, Welding Current and Welding Speed during the welding process. Welding systems use either a vision sensor or an Arc sensor, both of which are unable to control these parameters directly. Therefore, it is difficult to obtain necessary bead geometry without automatically controlling the welding parameters through the sensors. In this paper we propose a novel approach using fuzzy logic and neural networks for improving welding qualify and maintaining the desired weld bead shape. Through experiments we demonstrate that the proposed system can be used for real welding processes. The results demonstrate that the system can efficiently estimate the weld bead shape and remove the welding detects.

• Journal of Korea Entertainment Industry Association
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• v.15 no.3
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• pp.311-321
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• 2021

In this study, a smart switchboard for power supply of entertainment devices was developed for the following purposes. First, the heat generated when the high-temperature and humid air inside is cooled by the thermoelectric module is smoothly discharged to the outside of the switchboard, thereby maximizing the cooling effect. So, it is possible to prevent excessive temperature rise inside the switchboard. Various problems such as condensation inside the switchboard can be prevented by controlling the temperature of the switchboard in which a fire occurs due to excessive heat in summer, removing moisture due to the cooling effect, and generating heat instead of cooling in winter. Second, it is a smart switchboard control system that can reduce the salt that may permeate inside the switchboard. Third, the smart switchboard system is an IoT-controlled switchboard that collects environmental data using a variety of sensors and can remotely control devices through a smartphone, and can be easily used in various fields.