• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.821-828
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• 2011

This paper developed the algorithm for improving the performance the auto pilot in the autonomous vehicle system consisting of the Track keeping control, the Automatic steering, and the Automatic mooring control. The automatic steering is the control device that could save the voyage distance and cost of fuel by reducing the unnecessary burden of driving due to the continuous artificial navigation, and avoiding the route deviation. During the step of the ship autonomic navigation control, since the wind power or the tidal force could make the ship deviate from the fixed course, the automatic steering calculates the difference between actual sailing line and the set course to keep the ship sailing in the vicinity of intended course. first, we could get the transfer function for the modeling of ship according to the Nomoto model. Considering the maneuverability, we propose it as linear model with only 4 degree of freedoms to present the heading angle response to the input of rudder angle. In this paper, the model of ship is derived from the simplified Nomoto model. Since the proposed model considers the maximum angle and rudder rate of the ship auto pilot and also designs the Fuzzy controller based on existing PID controller, the performance of the steering machine is well improved.

• International Commerce and Information Review
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• v.16 no.4
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• pp.247-261
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• 2014

In this study, it investigates the highly controversial issue "low carbon car subsidy". Through the policy's intent, purpose, and necessity, it aims to present alternatives for automotive industry development. Introducing the low carbon car subsidy will bring a huge change to the vehicle purchase practices by changing vehicle purchase cost. It expects that this change will reduce greenhouse gas emission from vehicles. For successful settlement of the system, it shall set up the target sections for subsidy and levy appropriately in order to get the nation's consensus. Additionally, it has to conduct sufficient reviews the measures such as adjustment to the existing auto tax, divided payments of burden charge, etc before enforcing the system. In terms of the automobile industry, it must do their level best in technical development in order to meet the carbon dioxide emission level of imported cars until the enforcement. Also, the government has to strengthen its support to the industry.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.573-585
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• 2018

Services for navigation and entertainment through AI-based voice user interface devices are becoming popular in the connected car system. Given the classification of VUI agent developers as IT companies and automakers, this study explores attributes of agent persona and user experience that impact the driver's perceived safety and satisfaction. Participants of a car simulator experiment performed entertainment and navigation tasks, and evaluated the perceived safety and satisfaction. Results of regression analysis showed that credibility of the agent developer, warmth and attractiveness of agent persona, and efficiency and care of the UX dimension showed significant impact on the perceived safety. The determinants of perceived satisfaction were unity of auto-agent makers and gender as predisposing factors, distance in the agent persona, and convenience, efficiency, ease of use, and care in the UX dimension. The contributions of this study lie in the discovery of the factors required for developing conversational VUI into the autonomous driving environment.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.205-210
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• 2015

The auto industry has significantly evolved to the extent that much attention is paid to M2M (Machine-to-Machine) communication. In M2M communication which was first used in meteorology, environment, logistics, national defense, agriculture and stockbreeding, devices automatically communicate and operate in accordance with varying situations. M2M system is applied to vehicles, specifically to device-to-device communication inside cars, vehicle-to-vehicle communication, communication between vehicles and traffic facilities and that between vehicles and surroundings. However, communication systems are characterized by potential intruders' attacks in transmission sections, which may cause serious safety problems if vehicles' operating system, control system and engine control parts are attacked. Thus, device-to-device secure communication has been actively researched. With a view to secure communication between vehicular devices, the present study drew on hash functions and complex mathematical formulae to design a protocol, which was then tested with Casper/FDR, a tool for formal verification of protocols. In brief, the proposed protocol proved to operate safely against a range of attacks and be effective in practical application.

• Fire Science and Engineering
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• v.30 no.3
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• pp.1-6
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• 2016

More than five thousands transportation fires occurannually in Korea and the resulting destruction of property and loss of life is huge and results in traffic and environmental pollution. The recent development of automobile technology such as the hybrid concept and use of bio fuels makes fire protection even more difficult due to a lack of understanding of the new adapted system including vehicle engines. In this study, a numerical simulation was performed on a PSR (perfectly Stirred Reactor) to simulate an automobile engine and to clarify the effect of gasoline/ethanol surrogates as a fuel. The temperature, NOx and soot emissions were predicted to decrease with increasing ethanol content, but that of unburned hydrocarbons was found to increase dramatically. The result will provide not only the basic thermal characteristics for engines and their after-treatment systems, but also make it possible to assess the potential for fire events in these systems when an ethanol mixed fuel is used in gasoline vehicles.

• Journal of the Korea Convergence Society
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• v.9 no.3
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• pp.181-186
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• 2018

Car-sharing services are one of the successful model of sharing economies. The car-sharing service is a kind of car rental service that can pay the cost per minutes, also can makes it easy to book and return by smart phone at any time. Experts predict that the car-sharing services will likely dominate the auto market in the future by reducing the burden on consumers' purchasing cost of car and resolving the environmental issues caused by the vehicle. Therefore, a differentiated service strategy is needed to establish a competitive caching service among these companies. In this study, we surveyed differentiation cases by comparing and analyzing domestic caching companies, And customized service tailored to the situation and effective vehicle type infotainment. As a result of this study, the proposed service method change, customized service provision, and new platform application are expected to be detailed and in depth.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.57-67
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• 2013

Because many of the FOB key, anti-collision algorithm for a seamless multi-access is applied to the smart-key system. In this paper, we have designed and implemented improved anti-collision algorithm that dramatically reduces the communication response time required in the user authentication process immediately after by dynamically changing the order in which the request of the user ID as the user ID on immediately before in the smart key system for vehicles that use many of the FOB key. In order to evaluate the performance of the system the improved anti-collision algorithm is applied, we show the behavior of the algorithm implemented in the state actually mounted on the vehicle and verify that communication response time required for many of the FOB key was reduced by about 33% compared to existing algorithms.

• Journal of Environmental Science International
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• v.30 no.3
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• pp.219-234
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• 2021

Industrial emissions, mainly from industrial complexes, are important sources of ambient Volatile Organic Compounds (VOCs). Identification of the significant VOC sources from industrial complexes has practical significance for emission reduction. VOC samples were collected from July 2019 to June 2020. A Positive Matrix Factorization (PMF) receptor model was used to evaluate the VOC sources in the area. Four sources were identified by PMF analysis, including coating-1, coating-2, printing, and vehicle exhaust. The coating-1 source was revealed to have the highest contribution (41.5%), followed by coating-2 (23.9%), printing (23.1%), and vehicle exhaust (11.6%). The source showing the highest contribution was coating emissions, originating from the northwest to southwest of the sample site. It also relates to facilities that produce auto parts. The major components of VOC emissions from the coating facilities were toluene, m,p-xylene, ethylbenzene, o-xylene, and butyl acetate. Industrial emissions should be the top priority to meet the relevant control criteria, followed by vehicular emissions. This study provides a strategy for VOC source apportionment from an industrial complex, which is helpful in the development of targeted control strategies.

• Tribology and Lubricants
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• v.40 no.4
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• pp.111-117
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• 2024

Due to global CO₂ emission reductions and fuel efficiency regulations, the trend toward transitioning from internal combustion engine vehicles to electric vehicles (EVs) has accelerated. Consequently, the problem of EV failures has become a focal point of active research. The parasitic capacitance generated during motor-shaft rotation induces voltage that deteriorates the raceway and ball surfaces of bearings, causing electrical damage in EVs. Despite numerous attempts to address this issue, most studies have been conducted under high viscosity lubricant and low load conditions. However, due to factors such as high-speed operation, rapid acceleration and deceleration, motor heating, and motor system-decelerator integration, current EV applications have shown diminished stability in lubrication films of motor bearings, thereby leveraging the investigation to address the risk of electrical damage. This study investigates the electrical damage to rolling bearing elements in EV motor drive systems. The experimental analysis focuses on the effects of electric currents and operational loads on bearing integrity. A test rig is designed to generate high-rate voltage specific to a motor system's parasitic capacitance, and bearing samples are exposed to these currents for specified durations. Component evaluation involves visual inspections and vibration measurements. In addition, a predictive model for electrical failure is developed based on accumulated data, which demonstrates the ability to predict the likelihood of electrical failure relative to the duration and intensity of current exposure. This in turn reduces uncertainties in practical applications regarding electrical erosion modes.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1405-1411
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• 2011

It is very often for the experienced diesel locomotive drivers to identify the proper replacing time for the fuel adjustment tube only based on their experience. Because of that, sometimes the locomotive's fuel is burned out due to the unnecessary torque. Or sometimes, the locomotive does not operate with its accelerating performance because the fuel is not supplied at the appropriate moment. Meanwhile, recent typical auto vehicles provide drivers with the average fuel efficiency and the instant fuel efficiency in real-time. By providing the real time display mentioned above, it is one of the good examples that those drivers, who had driven their cars not properly and used a lot of fuel with their bad driving habits, obtain the efficient driving pattern by continuous educating effect. Similarly, if the diesel locomotive provides the train driver with the optimal driving pattern within a certain driving section, it will be effective for fuel saving. It is possible to make the most effective driving pattern by performing the repeated trial running especially for the railway because the track's operating routes, its grades, and etc are relatively precise. This research analyzes the result data which was obtained by many times trial running on the identical section after equipping the fuel use measuring device to a certain test vehicle, and confirms the fuel saving effect depending on the driving pattern along the test section. At the same time, the research to establish the optimal driving pattern was progressed.