• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.222-227
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• 2004

Korean High Speed Train(KHST) has been tested on the high speed test line in Osung site, since it was developed through the G7 Project Plan in 2002. It was also tested on the conventional line such as KyongBu and Honan Line to know the possibility of increasing the limited speed for the high speed trains. This paper introduces the method to improve the speed on the conventional line with body lateral acceleration among the several considered issues and explains the parameters related to those analysis, such as the cant deficiency, the radius of curve, speed and etc. When a train pass on the curved track, the lateral accelerations of body are divided into the quasi-static and the maximum accelerations according to the UIC 518 which is the international specification for testing and approval of railway vehicles from the point of view of their dynamic behaviour, especially for safety and ride comfort. This paper shows that it is safe and comfort from the results of test when KHST runs on the conventional line with the curves and proposes that the limited speed of conventional curved line could be changed to a little higher speed if the analysises of other fields are completed.

• Journal of Drive and Control
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• v.19 no.4
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• pp.1-9
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• 2022

The structure and operating principle of the 2-speed shift reducer were explained, the allowable bending stress value of the material was compared with the analysis result through FM structural analysis program, and the average stress distribution value of von Mises was performed on the gear root atmosphere. The structural safety of the 2-speed planetary gear reducer was verified through FM structural analysis. The natural frequency was calculated by applying the specifications of the planetary gears of the 2-speed gearbox, and the critical speed of resonance was calculated by calculating the natural frequency and the transmission error of the engaged gear pair. As a result of analyzing the critical speed, since it is formed higher than the actual operating speed range, it is considered safe because there is no resonance problem due to the suggested specifications of the planetary gears of the 2-speed shift reduction.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1720-1723
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• 2003

Recently, as the road capacity reaches a limit and environmental problems becomes serious, there exists a gradually increased need for railway vehicles that are environment-friendly, punctual, reliable and safe. Accordingly, in addition to conventional railroad vehicles, lots of vehicles are being newly developed. Korean High Speed Train has been developed for last 6 years to satisfy the need. Authors developed a measurement system for on-line test and evaluation of performances of Korean High-Speed Train. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the measurement system. By using the system, measurement and evaluation of the mechanical characteristics of motors and main transformers in Korean High Speed Train was conducted during test running. The measured results for the temperature characteristics of electric devices verify that the measurement system is accurate and reliable.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.5
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• pp.50-59
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• 1992

A critical speed analysis of a pump shaft has been investigated. Among various methods in the shaft critical speed calculation, a transfer matrix method has been examined in this research. After a brief review on the transfer matrix method, a modeling procedure for a continuous structure has been discussed. Then, a critical speed of a multistage pump shaft has been estimated up to several low modes. Throughout an analysis, parametric effects on the bearing stiffness, a degree of the modeling order, and attachmant of the impeller have been investigated. As an application example, a critical speed analysis of a verical pump which has been implemented in domestic electric power plants for cooling water circulation has been conducted in order to provide a safe operation as far as a pump vibration is concerned.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.112-122
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• 2006

Is the high speed train with 300km/h running speed safe from derailment when it meets the mid or small-size earthquakes? In the present step, it is not so easy to judge whether it'll be derailed or not during an earthquake. However, we could elevate the running safety of high speed train as making it slow or even stop. The main objective of this study is to make the domestic running regulation and the re-running manual for high speed train with reference to the standards of France, Japan etc. To do so, numerical analysis and experiment will be performed from the next year. In addition, we'll evaluate possible places of derailment during an earthquake and make a database based on the Geographic Information System to effectively manage them.

• Journal of information and communication convergence engineering
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• v.19 no.1
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• pp.61-66
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• 2021

An underwater remotely operated vehicle (ROV) has been implemented. It can inspect foreign substances through a CCD camera while the ROV is running in water. The maximum thrust of the ROV's running thruster is 139.3 N, allowing the ROV to move forward and backward at a running speed of 1.03 m/s underwater. The structural strength of the guard frame was analyzed when the ROV collided with a wall while traveling at a speed of 1.03 m/s underwater, and found to be safe. The maximum running speed of the ROV is 1.08 m/s and the working speed is 0.2 m/s in a 5.8-m deep-water wave pool, which satisfies the target performance. As the ROV traveled underwater at a speed of 0.2 m/s, the inspection camera was able to read characters that were 3 mm in width at a depth of 1.5 m, which meant it could sufficiently identify foreign objects in the water.

• Journal of the Korea Society of Computer and Information
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• v.20 no.12
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• pp.37-44
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• 2015

In this paper, we propose the assistance method to enable safe driving through analysis of dangerous driving behavior using real-time alarm by vehicle speed, azimuth data and smartphone. For this method, smartphone is receiving driving data from digital tachograph using communication. Safe driving habit is a very important issue to commercial vehicle because that driver's long time driving than other vehicle type driver. Existing methods are very inefficient to improve immediately dangerous driving habits during driving because proceed driving behavior analysis after the vehicle operation. We propose the new safe driving assistance method that can prevent traffic accidents by real-time and improve the driver's wrong driving habits through real-time dangerous driving behavior analysis and notification the result to the driver. We have confirmed that the method in this paper will help to improve driving habits and can be applied through the proposed method implementation and simulation experiment.

• International Journal of Computer Science & Network Security
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• v.23 no.11
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• pp.43-52
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• 2023

The paper aims to clarify how to make a decision using geographic information systems and how to choose the best route between two cities to suit the expectations of the driver and his sense of safety and comfort on the road. Use a special model for network analysis, where the network analysis tool relied on the following data (maximum speed of the road - number of intersections - road width - peak period) in choosing the best safe path. The paper concluded that the best safe route for refugees between the cities of Khartoum - Arqin crossing is ( Khartoum - Shendi - Atbara - Meroe - Abu Hamad - Wadi Halfa). We advise all GIS users to use the theories of spatial analysis when creating a new model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.193-201
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• 2014

This study provided safe sailing speed and appropriate passing time to areas of known strong current water to prevent marine accident of the ships. To the interpretation of these data which target Myeongnyang waterway, AIS data of the ship was collected from $12^{th}$ July to $15^{th}$ July 2010 and site environment was investigated on $4^{th}$ September 2010. On the basis of the collected data, the 'Minimum Navigation Speed' and 'Optimum Navigation Speed' were calculated. It has also considered the 'Spare control force' or allowance and the 'Respond Rudder Angle' for each tidal current speed. Additionally, it suggested the safe passing time to strong current area by analyzing tidal level and tidal current speed. The conclusion of the research are as follows : (1) If the flow rate is greater than 4.4 kn, it is difficult for the model ship to control herself by her own steering power and to cope with tidal current pressure force and yaw moment caused by the tidal current.. (2) The minimum navigation speed should be over 2.3 times the tidal current and the optimum navigation speed should be over 4.0 times the tidal current. (3) When spring tide, the optimum passing time at Myeongnyang waterway is between 30 minutes to 1 hour before the time of high/low water, and at 5 hours after high/low water, passing of ships should be avoided because it is time when the flow rate is over 4 kn.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.55-68
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• 2010

IEEE WAVE is going through the final standardization process as the wireless access technology which provides drivers in high-speed vehicles with safety-related information and commercial services This paper presents an application-layer protocol for safe driving assistant service and a service system emulator based on this protocol. The safe driving assistant system includes a construction zone information service and a vehicle crash notification service, an emergency vehicle notification service, a probing service and a dilemma zone decision assistant service. Emulator System design for verifying functions of system, The emulator consists of an emulator server that models the movement of all vehicles and road states and a number of clients that models functional units for OBUs, RSUs, and a traffic control center).