• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.113-120
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• 2014

In this paper, we examine Asymmetric Multi-Processing Environment to provide LDW service. Asymmetric Multi-Processing Environment consists of high-speed MCU to support rapid image processing and low-speed MCU for controlling with other ECU at the control domain. Also we designed rapid image process application and LDW application Software Component(SW-C) according to the development process rule of AUTOSAR. To communicate between two MCUs, timer based polling based IPC was designed. Also to communicate with other ECUs(Electronic Control Units), we designed CAN messages to provide alarm information and receiving CAN message to catch the Turn signal. We confirm the possibility of the various ADAS development using an Asymmetric Multi-Processing Environment and AUTOSAR platform. We also expect providing ISO 26262 functional safety.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.6
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• pp.83-91
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• 2006

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in longitudinal axis to achieve performance enhancements and improve stability. The flight control law of T-50 advanced trainer employs RSS concept in order to improve the aerodynamic performance and guarantee aircraft stability. The longitudinal center of gravity(X-c.g) varies as a function of external stores, fuel state and gear position. Shifts in X-c.g relate directly to longitudinal static margin in aircraft stability. This paper deals the maximum aft X-c.g for critical aircraft loadings and checks static margin limits using sensitivity such as damping, natural frequency, gain and phase margin. And nonlinear analysis was conducted for such as short period input. And also, this paper shows the T-50 aircraft stability based on the result of high angle of attack flight such as upright and inverted departure.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.232-240
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• 2015

Two types of track circuits are used in high speed railway car depots: one is High Voltage Impulse Track Circuit(HVITC); the other is AF track circuit. HVITC detects train occupation of blocks and broken rail; the AF track circuit is used for train onboard control system pretesting before departure. This testing is used to transmit train control information through the AF track circuit. The two systems are switched in turns for testing. We propose a system in which the AF track circuit is replaced by a loop cable that is installed on the inside rail; as such, engineers do not need to switch the systems. In cases in which the two systems run simultaneously, mutual interference may occur. In this paper, we identified this mutual interference by modeling of the two circuits.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.476-482
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• 2013

This study aims to enhance the effectivity of VTS(Vessel Traffic Service) control by investigating the minimum safe distance between vessel and vessel, vessel and land(obstacle) for the vessel's safe navigation within the VTS control area. In addition, to suggest basic data for the safe navigation, this study has done survey and analysis to each VTS center, and individual on the minimum safe distance to VTS operators of each ports of korea. Through ocean voyage by training ship, Singapore and Malacca strait's congested vessel traffic zone's control distance was compared and investigated the difference on safe distance by the different VTS operators. As a result, there was huge difference of minimum safe distance between the VTS operators belong to the same center. Over all, the port with gentle coastline, like donghae, the safe distance was wider than the other port. On the other hand, port with complex coastline and frequent entry and departure of the vessel, like mokpo, the safe distance was the shortest of all. Therefore, development of module suitable to port's natural conditions and traffic volume's necessity is required, for the operators affiliated to the same VTS center control according to formal method. Lastly, the full discussion by the expert group about establishment of standard control procedure in the future should be considered as well.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.103-111
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• 2021

The purpose of this study is to study a method for preventing collisions of multiple drones in controlled airspace. As a result of the study, it was proved that it is appropriate as a method to control drone collisions after setting accurate information on the ROI (Region of Interest) area estimated based on the expected drone path and time in the control system as a method to avoid drone collision. As a result of the empirical analysis, the diameter of the flight path of the operating drone should be selected to reduce the risk of collision, and the change in the departure time and operating speed of the operating drone did not act as an influencing factor in the collision. In addition, it has been demonstrated that providing flight priority is one of the appropriate methods as a countermeasure to avoid collisions. For collision avoidance methods, not only drone sensor-based collision avoidance, but also collision avoidance can be doubled by monitoring and predicting collisions in the control system and performing real-time control. This study is meaningful in that it provided an idea for a method for preventing collisions of multiple drones in controlled airspace and conducted practical tests. This helps to solve the problem of collisions that occur when multiple drones of different types are operating based on the control system. This study will contribute to the development of related industries by preventing accidents caused by drone collisions and providing a safe drone operation environment.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.25-36
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• 2005

In this study, we suggested a new approach method forecasting distribution demand of urban rail transit usign fuzzy control, with intend to reflect irregularity and various functional relationship between trip length and distribution demand. To establish fuzzy control model and test this model, the actual trip volume(production, attraction and distribution volume) and trip length (space distance between a departure and arrival station) of Daegu subway line 1 were used. Firstly, usign these data we established a fuzzy control model, nd the estimation accuracy of the model was examined and compared with that of generalized gravity model. The results showed that the fuzzy control model was superior to gravity model in accuracy of estimation. Therefore, wwe found that fuzzy control was able to be applied as a effective method to predict the distribution demand of urban rail transit. Finally, to increase the estimation precision of the model, we expect studies that define membership functions and set up fuzzy rules organized with neural networks.

• Journal of the Ergonomics Society of Korea
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• v.35 no.1
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• pp.11-27
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• 2016

Objective: The purpose of this study was to develop and evaluate high technology adaptive driving controls, such as mini steering wheel-lever system and joystick system, for the people with physical disabilities in the driving simulator. Background: The drivers with severe physical disabilities have problems in operation of the motor vehicle because of reduced muscle strength and limited range of motion. Therefore, if the remote control system with driver-by-wire technology is used for adaptive driving controls for people with physical limitations, the disabled people can improve their quality of life by driving a motor vehicle. Method: We developed the remotely controlled driving simulator with drive-by-wire technology, e.g., mini steering wheel-lever system and joystick system, in order to evaluate driving performance in a safe environment for people with severe physical disabilities. STISim Drive 3 software was used for driving test and the customized Labview program was used in order to control the servomotors and the adaptive driving devices. Thirty subjects participated in the study to evaluate driving performance associated with three different driving controls: conventional driving control, mini steering wheel-lever controls and joystick controls. We analyzed the driving performance in three different courses: straight lane course for acceleration and braking performance, a curved course for steering performance, and intersections for coupled performance. Results: The mini steering wheel-lever system and joystick system developed in this study showed no significant statistical difference (p>0.05) compared to the conventional driving system in the acceleration performance (specified speed travel time, average speed when passing on the right), steering performance (lane departure at the slow curved road, high-speed curved road and the intersection), and braking performance (brake reaction time). However, conventional driving system showed significant statistical difference (p<0.05) compared to the mini steering wheel-lever system or joystick system in the heading angle of the vehicle at the completion point of intersection and the passing speed of the vehicle at left turning. Characteristics of the subjects were found to give a significant effect (p<0.05) on the driving performance, except for the braking reaction time (p>0.05). The subjects with physical disabilities showed a tendency of relatively slow acceleration (p<0.05) at the straight lane course and intersection. The steering performance and braking performance were confirmed that there was no statistically significant difference (p>0.05) according to the characteristics of the subjects. Conclusion: The driving performance with mini steering wheel-lever system and joystick control system showed no significant statistical difference compared to conventional system in the driving simulator. Application: This study can be used to design primary controls with driver-by-wire technology for adaptive vehicle and to improve their community mobility for people with severe physical disabilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.581-588
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• 2020

This study examined a brake pad wear compensation method for an Electro-Mechanical Brake (EMB) using the braking test device. A three-phase Interior Permanent Magnet Synchronous Motor (IPMSM) was applied to drive the actuator of an EMB. Current control, speed control, and position control were used to control the clamping force of the EMB. The wear compensation method was performed using a software algorithm that updates the motor model equation by comparing the motor output torque current with a reference current. In addition, a simple first-order motor model equation was applied to estimate the output clamping force. The operation time to the maximum clamping force increased within 0.1 seconds compared to the brake pad in its initial condition. The experiment verified that the reference operating time was within 0.5 seconds, and the maximum value of the clamping force was satisfied under the wear condition. The wear compensation method based on the software algorithm in this paper can be performed in the pre-departure test of rolling stock.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.21-32
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• 2002

In accordance with the development plans of Ulsan harbor, Ulsan new harbor will be contructed considering supporting Ulsan harbor as a safe berthing and departure at single buoy mooring(SBM). In this study, we used a full-mission ship handling simulator adopting 300,000 DWT VLCC manoeuvered at the planned Ulsan SBM. Five masters who have had a long experience of ship maneuvering were called to carry out the simulations, of which each scenario were tried one, completed total of 68 times. The marine traffic safety was assessed in terms of 1) the closest point of approach(CPA) to other SBM and breakwater in the vicinity and the probability of crossing the restricted area of the closest SBM and fairway limit, 2) subjective evaluation such as the mental burden and the maneuvering difficulty of shiphanders, and 3) the opinions of shiphandlers. From the result of this simulation, we have a conclusion as follows; First, because crude oil berthing angle is so small by current S-OiL Co. crude oil buoy by SK Co. No 3 crude oil buoy different view SK Co. No 3 crude oil buoy and interference of current KNOC crude oil buoy, Berthing is impossible, and Emergency departing is very dangerous too operation impossible. Second it is desirable that SK Co. No 2 and No 3 Single buoy Mooring that do different view controls position so that to be not put in straight line each other. Third, SK Co. No 1 and 2 single buoy mooring that do different view to Onsanhang berthing and departing is seized by single buoy mooring by external force ship that set sail does faith control need.

• Journal of Korea Port Economic Association
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• v.29 no.2
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• pp.211-238
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• 2013

The Port Logistics Information System (Port-MIS) is the system that processes all of port management such as entry and departure of ships, using facilities within ports, port traffic control, cargo entering and carrying and tax collection in 31 trade ports over the whole country. Lately, The Port Logistics Information System (Port-MIS) has been reformed as a WEB-based system and established basis to provide real time information support structure, diversification of civil complaint system, and optimized civil complaint service by using wire and wireless internet. The typical study on the Port Logistics Information System was C/S program and EDI-centered. But it has significance to study on service quality measurement of WEB Port-MIS that has been served as a new web-based platform since April 2010, for there was no such a study until now.