• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.56-64
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• 2016

Damage of sea-crossing bridge by ship collision is related to estimate frequencies of overloading due to impact, and bridge accordingly must be designed to satisfy related acceptance criteria. Another important aspect is the management on increment of collision risk during the service period. In this study, related plan, main span length, air draft clearance and collision risk are analyzed for the interim assessment of Incheon Bridge focusing on the ship collision problem. In particular, for the increment of collision risk, the optimized navigation speed is proposed by reviewing the research findings and navigation guidelines etc. as a temporary expedient. Also basic procedure for reasonable prediction of target vessel and passage is established and probabilistic prediction method to embrace the uncertainty of the prediction is proposed as a fundamental solution. It is necessary to conduct further research on collision risk management and promptly carry out interim assessments of other marine bridges.

• Tribology and Lubricants
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• v.20 no.6
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• pp.322-329
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• 2004

Recently, a load/unload(L/UL) system is adopted to the hard disk drive(HDD) due to its advantages such as lower power consumption, larger data zone, simpler fabrication of disk due to no bumped parking zone, and rarer contact between slider and media. An analysis of the transient motion for the slider is very important to design an air bearing surface(ABS) of the slider to secure the stable performance of the system. During the L/UL process, however, there are several issues occurred such as contact or collision between slider and media. Sometimes this will cause the system failure. In this study, the dynamics of a pico slider during the loading process are investigated through numerical simulation using FEM analysis and experiment. Ramp profile and angular velocity of the swing arm actuator are very important parameters for the design of L/UL system to avoid collision between slider and disk.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.173-178
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• 2018

The vehicle collision speed in mid and high range can be checked by EDM(Event Driven memory) data recorded when the air bag works. But it's difficult to estimate the low speed of vehicle collision. And estimating the speed is important because the injury level can be changed by the impact speed. The study proposed an estimating algorithm by analysing the images recorded in car blackbox instrument. Low speed rear collision accidents simulated with wire winding motor for various vehicle types. The study estimated the impact speed with the ratio of the distance change between two vehicles and the length change of the number plate of front vehicle. The closer the vehicles are, the larger the plate length is. You can estimate the impact speed with the ratio. The impact speed is calculated with the initial distance for a specific length of number plate in the algorithm. The results can be applied to the linear rear collision because the angle of impact was not considered in this study.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.81-87
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• 2010

This study presents the results of collision and lift analyses of a cylinders-connected protector under stock anchor colliding and dragging. For the analyses, the terminal velocity of the stock anchor was obtained first, and, then, the velocity was used to calculate the falling distance of the stock anchor in air. In addition, two other falling distances were considered for purposes of comparison. From the finite element analyses, using ANSYS, the maximum responses obtained from the stock anchor colliding and dragging were obtained and compared for different collision distances (3, 5, and 8.83 m) and dragging angles (0, 30, 60, $90^{\circ}$). Then, the maximum displacements and stresses were discussed, along with the strength and dimensions of the protector. Finally, conclusions were made for the maximum responses.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.676-684
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• 2004

Many researchers have been carrying on study to figure out the exact collision efficiency between bubble and floc. Collision efficiency can has generally been quantified by using trajectory analysis which uses the hydrodynamic, the electrostatic and van der waals forces. Two types of method are considered to induce the hydrodynamic force in the trajectory analysis. One is to use stream function and the other is to use mobility function. There was some difference between stream and mobility function depending upon modelling factors and conditions in trajectory analysis.

• Journal of Fashion Business
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• v.15 no.5
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• pp.103-114
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• 2011

During a wearer's movement, the apparel fabric layers collide each other in a highly complicated manner. The collision involves cloth-cloth, and cloth-body collision. The diversity of the textile fabrics, including silk, wool, cotton, and other synthetic fibers, together with the complex details of the apparel construction, makes the collision and other calculation procedure involved in the 3-dimensional clothing software system much more complicated. Therefore, there is a need to measure the behavior of the fabrics during the fabric collision cycles. In this study, as a first step, static measurements pertinent to the factors governing the appearance of the apparel fabrics were implemented. The drape profile, stiffness(Sd and Sf), tensile properties, thickness, and the air permeability were measured. The correlation between the parameters were calculated and reviewed. It is found that there is a high correlation of 0.97 between the actual fabric drape parameters and the 3D virtual fabric drape parameters. The measured drape coefficients of the fabrics show relatively good correlation with the measured fabric stiffness.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.630-638
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• 2009

In this paper, we propose a new SCADE-based integrated simulator for aircraft mid-air collision avoidance. The new simulator is designed to provide a convenient simulation environment for analyzing the limitations of the existing collision avoidance system(CAS) and for realizing more realistic collision environment into the CAS performance evaluation. Furthermore, we have developed a scenario editor for TCAS-II performance analysis to simulate actual flight environment which is difficult to experiment. The performance of the proposed simulator for typical collision scenarios is demonstrated by simulation using the proposed scenario editor.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.235-241
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• 2004

The dissolved air flotation (DAF) process has been widely used for removing suspended solids with low density in water. It has been known as measuring the size of microbubbles precisely which move upward rapidly in contact zone is difficult. In this study particle counter monitoring (PCM) method is used to measure the rising microbubble after injection from a nozzle. Size and distribution curve of microbubbles are evaluated at different conditions such as pressure drop at intermediate valve, length of pipeline between saturation tank and nozzle and low pressure. And the efficiency is also checked when it collides with different size floc. The experimental results show the following fact. As the final pressure drop occurred closer to a nozzle, the bubble size became smaller. And small bubble collides with large floc as well as small one because of its physical characteristic. However large bubble collides well with large floc rather than small one since hydrodynamic flow in streamline interferes to collide between two. With performing computational process by mathematical model we have analyzed and verified the size effect between bubble and floc. Collision efficiency is the highest when P/B ratio shows in the range of 0.75 < P/B ratio ($R_{particle/Rbubble}$) < 2.0.

• Atmosphere
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• v.30 no.2
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• pp.125-139
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• 2020

On 6 August 2018, heavy rainfall of daily precipitation of more than 200 mm occurred in the Yeong-dong coastal area, and especially, 1-hour precipitation of 93 mm (0251~0351 LST (local standard time) 6 August) at Gangneung station, ranked second in the history of meteorological survey of the station. In this study, this heavy rainfall case over the Gangneung area would be studied to investigate the process in which the heavy rainfall occurred. A developed ridge moved toward the Yeong-dong coastal area from the Maritime Province in Russia. The approaching of the ridge led to the northeasterly cold wind over the coastal region, causing the collision between the incoming northeasterly cold wind, and the humid and warm (convectively unstable) air located over the Yeong-dong area. This collision led to a strong convergence (maximum -206 × 10^-5 s^-1) at 925 hPa level over the vicinity of Gangneung at 0300 LST 6 August, resulting updraft of up to about 4.4 m s^-1 at 700 hPa level over the area. This strong updraft forced to lift rapidly the convectively unstable, warm and humid air layer, located over the vicinity of Gangneung, leading to the heavy rainfall (1-hour precipitation of 93 mm) over the area.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.352-357
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• 2016

More recently, workers and passengers of casualties has increased by rear-end collisions of unexpected while working on the road. Recently attracted air chamber TMA mounting car accidents which occurred in 3 years, and analyzed the effect of reducing the shock absorption and protection performance and casualties. There is a risk of the vehicle AIS4 more injury of high five accidents of casualties risk, also, was the analysis that there is risk of death was avoided by the air chamber TMA and SGT. Therefore, by mounting the TMA in the rear-end accident, so you can reduce the death and casualties, it must be increased this of attach rate for road construction vehicle.