• Proceedings of the KSR Conference
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• 2004.10a
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• pp.616-621
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• 2004

In this paper, the crush characteristics of a tilting train express (TTX) M-car design are evaluated with a head-on collision scenario. Its body shell is divided into three parts - front end, middle section, and rear end. For each part, crush-force relation is evaluated numerically through 3-dimensional shell element analysis with LS-DYNA. TTX's embody structure is a hybrid type structure made of steel and composite materials. Composite sandwich panels are modeled as layered shells whose layers have different material properties. And a damage material model is used to consider the effect of stiffness degradation during deformation. The crush characteristics obtained from these calculations will be used as material modeling data of full-rake collision analyses.

• The Korean Journal of Air & Space Law and Policy
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• v.27 no.1
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• pp.103-122
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• 2012

Nowadays, advanced countries and international community in which provide many services and profits due to rapid progress space science and technology whereas there is rising possibility of damage by collision of space object and increase of space debris. I will propose the concept and range of damage in the basis of review of space treaty and space liability convention as form of international order to fair and complete compensate to victim of accident and hazardous space activity. And, I will try to discuss possibility of compensation on personal damage and mental damage, scope of material damage, possibility of compensation about environmental contamination, issue of satellite data sending, place of damage, and so on. Also, I would like to propose establishment of space tribunal and regional cooperative agency.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.885-892
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• 2015

In this study, we simulate the railway crash accident that occurred at the Sangwangsimni station on the Seoul Metro Line #2, and we propose a solution to minimize the damage. We use LS-DYNA, which is the commercial software employed for collision analysis to perform 1-D and 3-D simulations for the recurrence of accidents. By performing 1-D simulations, we analyze the load, displacement, absorbed energy of the couplers, and acceleration of vehicles, and we evaluate the safety in accidental collisions. By performing 3-D simulations, we analyze the deformation of the car and over-ridding. We propose methods to improve the safety in collisions involving railway vehicles, and we perform collision accident simulations to determine improvements when applying a high-performance energy absorber to the front car.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1144-1151
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• 2010

The increasing number of orbital debris objects is a risk for satellites because of past 50 years space activities. The LEO (low earth orbit) where KOMPSAT-2 and KOMPSAT-5 are operated is including about 84% of the total space debris. Thus, the space missions need to consider the space debris. In this paper, we analysis the orbit characteristics and spatial density of space debris about KOMPSAT-2 that is in activity and KOMPSAT-5 that will be launched in 2010. Analyzed probability damage and collision with space debris are also performed. ESA MASTER2005 and of NASA DAS2.0 are used to analysis KOMPSAT mission environment. As a result, it is noted that KOMPSAT-2's collision probability was far more than KOMPSAT-5 because KOMPSAT-2's orbit has high density composed space debris.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.26-32
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• 2017

Enlargement and speed-up of a ship and diversification of ship's type have served to greatly increase the importance of marine transport means. It's reported that accident occurrence frequency of collision is high next to engine damage among the ship accident types, and that the accident ratio according to human factors is also high. In addition, ship accidents come to occur caused by complex cause factors rather than a sole cause factor, it is necessary to investigate the cause factors through the written verdict. This study proposed the cause factors of collision ship accident on the basis of human factors in collision ship accident among the written verdicts provided by the Korean Maritime Safety Tribunal, and inquired into the cause factor and effect through the correlation analysis of accident occurrence factors. Also, this study predicted the collision accident through analyzed the major cause factor of the occurrence at the zero minute when collision on the basis of the time taken from the time point of detecting collision of ships to the time point of collision occurrence. This study used commercial software-Statistical Package for Social Sciences (SPSS Ver21.0) to do correlation analysis. For time analysis, this study analyzed the cause factor and time by analyzing the time taken from the time point of detected ships to the time point of collision occurrence on the basis of the written verdicts. The study analysis showed that there were many cases of collision ship accidents occurrence caused by more than two sorts of cause factors, and that the case (zero minute) where there is no time to spare for collision avoidance accounted for 36.1 %, and negligence in guard or surveillance of the other ship, and sailing while drowsy, or drinking was a contributor to an accident. Poor watch keeping is very strong relationship with pool ready for sail.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.577-586
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• 2022

The increasing trade volume between Korea and China has rapidly expanded the maritime transport between the two countries. However, safety, particularly considering the ship collisions in the Yellow Sea and East Sea waters, has not been fully ensured. These collision accidents in that region endanger traffic safety and the marine environment, moreover, it has the potential to cause legal complexity because Korea and China haver domestic legislation, that are considerably different in some aspects. International conventions and domestic legislation in China provide detailed laws with respect to ship collisions, however, the theory of ship collision infringement still needs to be improved, enriched, and developed. Because these laws are not very clear on the resolution of disputes resulting from ship collisions, we focused on the final judgments by the Supreme Court of China (SPC), and the judicial judgments set by the Maritime Court of China. This study aimed to explore the domestic legislation applicable to disputes related to ship collisions in China, and comparatively investigate the legal provisions of Korea and China on the issue of ship collisions, particularly on the aspect of damage compensation, fault ration, and liability apportionment.

• Journal of Surface Science and Engineering
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• v.46 no.3
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• pp.120-125
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• 2013

This investigation was to identify the electrochemical corrosion protection conditions to minimize the cavitation damage by generating hydrogen gas with the means of hydrogen overvoltage before the impact pressure of the cavity is transferred to the surface. The hybrid potentiostatic test method is designed to evaluate a complexed cavitation and electrochemical characteristic for ALBC3 alloy that is diverse and its broad applications fields in marine industry. The surface observation showed that neither the cavitation damage nor the electrochemical damage by the hydrogen gas generation occurred in the potential of -2.6 V under the cavitation environment. In the potentiostatic experiments under the cavitation environment, the cavities were reflected or cancelled out by the collision of the cavities with the hydrogen gas generated by the hydrogen overvoltage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4677-4684
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• 2010

In this study, the safety of passenger could be investigated by the analysis of car body to absorb he shock onto automotive door. The damage at door happens because of the collision of automotive door or parking accident due to the carelessness of driver. This door was modelled by CATIA program. The damage process of this model by impact was analyzed and investigated through ANSYS program. The contours of equivalent stress and strain were obtained. It can be known how damage of door becomes under impact and this study result can be thought to contribute for the design of door considering impact safety.

• Journal of Surface Science and Engineering
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• v.45 no.1
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• pp.25-30
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• 2012

The galvanostatic tests for corrosion protection are conducted at various applied current densities during 93,600 sec, and evaluated in terms of the variations in current density with time and in the potential at the applied current density. In addition, the corrosion damage depth is analyzed with 3D analysis optical microscope after galvanostatic tests. In this study, it was investigated to decide condition of the corrosion protection gavalnostatic method for Cu-Al alloy that has an excellent corrosion resistance. In the galvanostatic test under the cavitation environment, the energy was reflected or cancelled out by the collision with the oxygen gas generated by the oxygen reduction action. The surface observation showed neither the cavitation damage nor the electrochemical damage in the current density over 0.01 $A/cm^2$ in the dynamic state under the cavitation environment.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1025-1026
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• 2008

The level crossing collision accident which comprises more than 90 percent of all level crossing accidents is one of the most serious safety problems. There is a critical need for providing safe strategy and is focusing on the level crossing information rather than measures at a grade crossing. This study is intended to develop technology for accident prevention and damage reduction based on accident cases analysis result and improvement direction to complement shortcomings of safety equipment of conventional level crossing and to establish safety of travelers(train, motor vehicle, person).