• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.4
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• pp.32-37
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• 2010

One of the most common engineering processes using plastics is the injection molding. In addition, plastics are utilized over the entire areas in our life including cars and home appliances among others for their characteristics with no deterioration even after a long time, as well as for their light weights in addition to their good durability. This paper aimed to minimize defects through prior analyses on the weld line, air traps, filling time, molding temperature and deformation patterns among others while carrying out interpretations on the cooling, filling and deformation in the injection process using the moldflow for rear lamp reflectors among components for a car in making parts through the coating process after injection.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1127-1128
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• 2010

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.416-421
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• 2011

This study was initiated to prevent rear-end collision which causes the most frequent human damage by agricultural tractors. Therefore, this study was aimed to evaluate the luminous performance of a stop lamp for an agricultural tractor which could reduce rear-end collision. The performance test of luminous intensity distribution was conducted for a total of 12 tractor models classified by size (above 44 kW for large, 30~43 kW for medium, and below 29 kW for small) and production area (domestic, foreign manufacture) in accordance with Regulation No.7 of UNECE Vehicle Regulations-1958 Agreement considering ${\pm}$20 standard deviation. Three out of 5 large, 3 out of 4 medium, and all small tractors were resulted as inadequate for the test criterion. This study found that the luminous performance results were better as the size of agricultural tractors became bigger. One out of 4 foreign and 2 out of 8 domestic manufacturers were suitable for the test criterion, and overall no difference from the luminosity test results was observed between domestic and foreign manufacturers. In addition, the measuring points, HV, 5L, 5R, 5U and 5D with the minimal luminosity revealed flaws (80% of the proportion of faulty products). Therefore, it is urgent to improve the quality for measuring points (HV, 5U, 5L, 5R, 5D) of stop lamps to apply Regulation No. 7.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.109-116
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• 2016

Polymethyl methacrylate is commonly used in the outer lens of automotive rear lamps. However, if the lens warps above the allowable limit, it may lead to faulty connection with the housing, and failure of the assembly. This study investigated the effects of gate diameter and cooling line distance in the mold design for automotive outer lens. The optimal gate diameter and cooling line distance to minimize the warp of the outer lens were derived as 3.0 mm and 50-60 mm respectively, and the cooling temperature to minimize warp was shown to be $60-80^{\circ}C$ (mold surface temperature $48-67^{\circ}C$). A higher cooling temperature may somewhat mitigate the warp, but is undesirable because it may cause injection molding problems, such as sinks. A mold was constructed matching the optimal design and the produced lens properties, particularly the degree of warp, were comparable with the CAE predictions.

• Tribology and Lubricants
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• v.30 no.3
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• pp.183-188
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• 2014

In this paper, we present our analysis of tribological failure examples for an anti-lock brake system(ABS) in a car. The study range of this paper is to improve the quality of ABS system by analyzing with sensor, computer, actuator and oil lines. In the first example, the brake leak from hydraulic supply line in a caliper on the rear left side of the ABS hydraulic modulator. This produces the sponge phenomenon, where the car does not brake even when the driver operates the brake pedal. The hydraulic unit operating ABS is actuator that play role regulating drive condition according with the oil pressure supplied with wheel of a car. In the second example, the service man does not completely tighten the fixed bolt after repairing the car. This causes the ABS warning lamp to light up as the ABS wheel speed sensor cannot detect whether the ABS has been activated. In the third example, the ABS electronic control unit is separated from the soldered part of the inner circuit board. Consequently, the ABS fails in control because the ABS motor pump receives no-signal for the hydraulic unit. The wheel speed sensor has to large durability because of giving signal of acting condition to computer by detected the acceleration and deceleration of wheel of a car. In the fourth example, the ABS warning lamp lights up of when cracks propagate in the circuit board soldering part. The circuit of this computer is very important part for input and output the operating signal of system. Such failures can aggravate the durability of the ABS. Thus, the ABS needs to be optimized to eliminate malfunction phenomenon.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.379-382
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• 2005

This study proposes an effective algorithm that can render a realistic image of a lighting environment, especially an automotive rear lamp, using the backward ray tracing method. To producea realistic image similar to that perceived by the human eye, the incident light energy at the eye point estimated by a ray tracing algorithm is represented by XYZ tri-stimulus values, which are then converted into RGB values considering the particular display device.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.102-106
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• 2012

The purpose of this paper is to study the failure cases in relation to system of Air Bag in vehicle happened in the field. In the first example, it was separated the soldering parts connected the wire pin between air bag module and clock spring of air bag. Whenever the pin shake by the car's vibration, the driver verified the malfunction phenomenon appeared air bag warning lamp on instrument panel in front of driver's seat. in car inside room. The second example, it verified the warning lamp lighting phenomenon of air bag by produced the circuit plate non-contacting of single an element in air bag electronic control unit. The third example, it verified the light of air bag warning indicator lamp by separated with soldering parts connecting inner pin and resistance terminal of seat belt pretensioner using passenger seat. The fourth example, when the passenger car crash a back of truck, the former bumper get jammed under the latter as the roof height of car low less than that. Therefore, the impact of Car's collision verified that don't transfer with body frame of vehicle because of no attachment impact sensor in it.