• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.494-500
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• 2020

Maneuvering vessels in the harbor is an interesting problem in marine cybernetics. The vessel, operated by the pilot and moving very slowly in shallow water, usually is assisted by thrusters, the main propulsion system, and tugboats. In this paper, we suggest a new vessel berthing technique using dampers (cylinder-type fenders) and a system of winches for complex and dangerous berthing situations. We found that control of the fender stroke and rope tension enabled a safe and quick berthing process. The effectiveness and usefulness of this berthing system was verified using a ship of about 2,000 tons.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.41-47
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• 2020

As modern industries are highly being developed, it is required that mechanical parts have to be manufactured with a high precision. In order to have precise parts, error-free designs have to be done before manufacturing with accuracy. For this intention being fulfilled, a mechanical analysis is essential for design proof. Nowadays, FEM simulation is a popular tool for verifying a machine design. In this paper, an impeller, being utilized in a compressor or an oil mixer as an actuator, is studied for an evaluation. The purpose of this study is to present a safety of an impeller for a proof of its mechanical stability. A static analysis for stress, strain, and deformation within a regular usage is examined. This simulation test shows 357.26×106 Pa for maximum equivalent stress and 0.207mm for total deformation. A fatigue test is carried to provide durability and its result shows that minimum safety factor is 3.2889, which guarantees that it runs without a fatigue failure in 106 cycles. The natural frequencies for the impeller is ranged from 228.09Hz to 1,253.6Hz for the 1st to the 6th mode. Total deformations at these natural frequencies are shown from 6.84mm to 12.631mm. Furthermore, Campbell diagram reveals that a critical speed is not found throughout regular rotational speeds. From the test results for the analysis, this paper concludes that the suggested impeller is proved for its mechanical safety and good to utilize at industries.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.521-526
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• 2020

In this paper, we propose a design method and process for hybrid V2X communication platform that combines WAVE communication and LTE-V2X communication which are C-ITS communication protocols for vehicle environments and Legacy LTE communication which is a commercial mobile communication for evaluating the autonomous platooning platform of commercial vehicles. For a safe and efficient autonomous platooning platform, an low-latency communication function based on C-ITS communication is required, and to control it, commercial communication functions such as Legacy LTE, which can be connected at all times, are required. In order to evaluate such a system, the evaluation equipment must have the same level of communication performance or higher. The main design contents presented in this paper will be applied to the implementation of hybrid V2X terminals for functional evaluation.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.239-249
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• 2022

This study aims to analyze and compare the activating factors of domestic and overseas scuba diving resorts. Our delphi survey was conducted three times in 30 experts who involved in operation and management including scuba diving resort management representative and training team leader. As a result of comparing the activating factors at domestic versus overseas, it was found that common important activating factors included expansion of convenient facilities at public diving places, installation of safety and medical facilities for divers, development of first aid system including AED and oxygen ventilator, requirement of convenient facilities such as water lift and toilet in diving boat, installation of diving boat screw safety system, local boat operation guideline, regular course training program for scuba diving, employment of professional scuba diving instructor and guide, communication and promotion through various SNS portals, promotion by divers' word of mouth, involvement in regional Diving Resort Association, involvement in Korean Diving Association, communication and mutual benefit with local fishing villages, and linkage policy with local tourism industry.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1349-1354
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• 2021

An All-in-one LED lantern is a light device to determine the fairway of ships in operation. The current all-in-one LED lantern powered by solar energy is challenged by insufficient power capacity due to limited sun hours. This article presents an all-in-one 9-Nautical mile LED lantern driven by solar and wind power that is abundant maritime renewable energy. Furthermore, the remote smart monitoring system is developed. A smart control system capable of remote control of the lantern was implemented by using the LED lantern device and monitoring system as IoT. This technology that realtime condition monitoring and remote control are developed for safe ship navigation. We expect that maintaining the accuracy and consistency of LED lanterns prevents marine accidents and reduces social costs.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.272-280
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• 2022

An aircraft carrier is a combat ship that acts as an aircraft base at sea and performs combat through aircraft mounted as a military ship operating the aircraft. The Navy proposed a 40,000-ton light aircraft carrier operation plan that could be equipped with vertical takeoff and landing fighter jets and helicopters around 2033, and based on this, this study examined the operation of aircraft control equipment among the aviation support systems required for operating light aircraft carriers in Korea. PriFly, TWR's ILARTS, ILM for airspace control, ASR, PAR, LAAS or RNAV, PALS (JPALS) for access control are required as essential equipment, and communication network and SCATT-16 are required along with URN-25 TACAN, ICLS (El/Az), ACLS OLS, MOVAS, IFLOLS, etc. This study consists of two parts, and part 2 will describe a specific control method on an aircraft carrier.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.2
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• pp.447-463
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• 2022

Artificial Intelligence (AI) technology is a major technology that develops smart ships into autonomous ships in the marine industry. Autonomous ships recognize a situation with the information collected without human judgment which allow them to operate on their own. Existing ship systems, like control systems on land, are not designed for security against cyberattacks. As a result, there are infringements on numerous data collected inside and outside the ship and potential cyber threats to AI technology to be applied to the ship. For the safety of autonomous ships, it is necessary to focus not only on the cybersecurity of the ship system, but also on the cybersecurity of AI technology. In this paper, we analyzed potential cyber threats that could arise in AI technologies to be applied to existing ship systems and autonomous ships, and derived categories that require security risks and the security of autonomous ships. Based on the derived results, it presents future directions for cybersecurity research on autonomous ships and contributes to improving cybersecurity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.27 no.1
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• pp.97-102
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• 2023

IoT is being used in a lot of industry domain such as smart home, smart ocean, smart energy, and smart farm, as well as legacy information services. For a server, an IoT device using the same protocol is a trusted object. Therefore, a malicious attacker can use an unauthorized IoT device to access IoT-based information services and access unauthorized important information, and then modify or extract it to the outside. In this study, to improve these problems, we propose an IoT device authentication system used in IoT-based information service. The IoT device authentication system proposed in this study applies identifier-based authentication such as MAC address. If the IoT device authentication function proposed in this study is used, only the authenticated IoT device can access the server. Since this study applies a method of terminating the session of an unauthorized IoT device, additional research on the access deny method, which is a more secure authentication method, is needed.

• Smart Media Journal
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• v.12 no.3
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• pp.120-128
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• 2023

There are various ICT technologies continuously being developed to reduce damage by industrial accidents. And research is being conducted to minimize damage in case of industrial accidents by utilizing sensors, IoT, big data, machine learning and artificial intelligence. In this paper, we propose a design method for a smart device capable of multilateral communication between devices and smart repeater in the communication shaded Areas such as closed areas of industrial sites, mountains, oceans, and coal mines. The proposed device collects worker's information such as worker location and movement speed, and environmental information such as terrain, wind direction, temperature, and humidity, and secures a safe distance between workers to warn in case of a dangerous situation and is designed to be attached to a helmet. For this, we proposed functional requirements for smart devices and design methods for implementing each requirement using sensors and modules in smart device. And we derived evaluation items for performance evaluation of the smart device and proposed an evaluation environment for performance evaluation in mountainous area.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.51-61
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• 2006

An efficient and accurate hybrid reliability analysis method is proposed in this paper to quantify the risk of an axially loaded single pile considering pile-soil interaction behavior and uncertainties in various design variables. The proposed method intelligently integrates the concepts of the response surface method, the finite difference method, the first-order reliability method, and the iterative linear interpolation scheme. The load transfer method is incorporated into the finite difference method for the deterministic analysis of a single pile-soil system. The uncertainties associated with load conditions, material and section properties of a pile and soil properties are explicitly considered. The risk corresponding to both serviceability limit state and strength limit state of the pile and soil is estimated. Applicability, accuracy and efficiency of the proposed method in the safety assessment of a realistic pile-soil system subjected to axial loads are verified by comparing it with the results of the Monte Carlo simulation technique.