• Proceedings of the KSME Conference
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• 2007.05a
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• pp.602-607
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• 2007

The heavy duty diesel engine must have a large output for maintaining excellent mobility. The compacted graphite iron (CGI) is a material currently under study for the engine demanded for high torque, durability, stiffness and fatigue. In this study, three dimensional finite element model of a heavy-duty diesel engine was developed to conduct the stress analysis by using property of CGI. The FE model of the heavy duty diesel engine section consisting with four half cylinder was selected. The heavy duty diesel engine section include cylinder block, cylinder head, liner, bearing cap, bearing and bolt. The loading conditions of engine are pre-fit load, assembly force and gas force.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.243-247
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• 2009

A Radioactive constraint of the nuclear fuel assembly irradiated by neutron during normal operation cycle of the nuclear power plant is typically on the order of about 3 kGy/h. In order to inspect nuclear fuel assembly using a VT (vision technology) system, the light such as halogen lamp is used. As the halogen lamp has lower color temperature than the sun light, the objects under halogen lamp illumination are seemed to be tinted with red. In this paper, high brightness LED is considered to be used as the light source of VT system. The high brightness LED, which is a key light source of the VT system, have been gamma irradiated at the dose rate of 4 kGy/h during two hours up to a total dose of 8 kGy. The radiation induced color-center in the LED housing cap made of plastics materials is observed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.672-680
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• 2018

The opening angle of the duct cap assembly during the operation of a refrigerator ice dispenser was evaluated by transient structural analysis, and an improved design to maximize the opening angle was obtained. The opening angle of the existing design was found to be 78% of the upper limit. Several design modifications were proposed and analyzed to examine the effects of the design factors on the opening angle. As a result of the design modifications, the opening angle was improved by changing the lever material to a material with a high elastic modulus, moving the position of the support to the motor side, or increasing the lever shaft diameter. Considering the manufacturing cost of the new design, the design modification changing only the lever material was found to be the best because it does not require a change in the structure of the ice dispenser case. In conclusion, the opening angle can be improved by up to 95% of the upper limit value if the lever material is changed to an aluminum alloy. The methods and results presented in this study were found to be of great help in designing the duct cap assembly structure to facilitate the discharge of ice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2013-2020
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• 2010

This paper presents a study on the modeling for transparent toaster with a cap of folding type. The toaster was modelled to solve problems of customer's unsatisfaction such as heat loss, input of a piece of dirt, unidentified heating state of sliced toaster. Rapid prototyping was followed by the first modeling, and the second modeling was implemented in order to solve the problems of the first modeling such as interference of holder and door, and the third modeling was developed with a cap of folding type through analysis of assembly and simulation. The 3D modeling tool used in this paper was Pro/Engineer 4.0. The modeling was designed to minimize heat loss and structured with transparent outer case. So the toasting procedure will be identified with the naked eye, and the transparent toaster will improve the customer's aesthetic satisfaction.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.111-116
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• 2011

Three-dimensional finite element analyses have been performed to improve the durability of bulkhead. To keep pace with design changes and concentrate on regions of interest, SUBMODEL technique in ABAQUS was used for analysis. An analysis was conducted with following load cases: 1) Cap press-fit, 2) Bearing crush, 3) Bolt assembly, 4) Hot assembly, 5) Firing load, 6) Alternating firing load, 7) 2nd hot assembly. Fatigue analysis was done using commercial software FEMFAT and fatigue factors at the interested regions such as bolt tip area, counter bore, breathing hole, honing clearance were calculated and compared to aid design validation. Finite element modeling in the area of thread engagement used a simple constraint equations. Increasing bolt length, to a minimum of 39 mm above joint face gives a better fatigue resistance to the bulkhead. Breathing hole helps not only circulate the air in the crankcase but also fatigue resistance of bulkhead by relieving the stress at the critical locations.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.1
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• pp.37-42
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• 2020

This study is for a bulletproof experiment through speed acceleration of steel ball(2.385 mm) at the laboratory level. The secondary propulsion method is used for speed acceleration, which uses a sabot assembly consisting of a sabot body, a plunger, water, and a sabot cap. At the core of the secondary drive, it is important that the energy in the water of the private particle is transferred well to the steel ball. The experiment was conducted by selecting a plunger that pushes water and water charged with variables. judging that the longer the contact time, the greater the energy transferred to the steel ball. As a result of experiments with each variable, the amount of water does not affect the speed acceleration efficiency of the steel ball and, when the length of the plunger is increased by 200 %, the speed of the steel ball can be accelerated up to 130 m/s.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.553-556
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• 2005

It is analyzed that WAP packet transmission time to improve performance of WAP using SAR algorithm in Bluetooth channel. The order for SAR algorithm to improve the transfer capability, it is fragmented in WTP total messages that are coming down from upper layer and then the packets are sent one at time in baseband. And it is studied that transmission time for WAP over bluetooth according to DM1, DM3 or DM5 packet type using SAR algorithm in Bluetooth piconet environment. This SAR algorithm decreases WAP packet transmission time of L2CAP baseband packets by sending packet which are spanning multiple slots.

• 대한공업교육학회지
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• v.33 no.1
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• pp.282-296
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• 2008

Present automobile robot welding use $CO_2$ inert gas as a shielding fluid. The inert gas is spreading out and consumable. This present welding mechanism interfered with the welding nozzle. After welding several places have welding defects. Therefore, to reduce the $CO_2$ inert gas and to avoid interference with the material and to increase production modified nozzle which composed of cap and tip are needed. Suggested modified nozzle assembly composed of two stages i.e. $1^{st}$ and $2^{nd}$ stage. At the second stage it has 8 holes which is 3mm of diameter around the circumference. On the base of experimental results the inert $CO_2$ gas discharge reduced to 47% and welding defects decreased also. Modified two stage welding cap can be applied to the present robot welding machine and save the prime cost.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.144-148
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• 2005

Cylinder frame manufactured by casting is assembled with the components such as cylinder head, cylinder liner and main bearing cap, etc. The mechanical contact between all of the neighboring components due to bolt tightening was taken into consideration. The loads used in structural analysis were the bolt tightening forces induced by hydraulic jack and the dynamic forces calculated from kinematic analysis. The difference of forces between the neighboring cylinders was taken into account. The maximum stress, stress amplitude and mean stress calculated from the results of structural analyses were used to evaluate the static and fatigue strength. Gray cast iron which is material of cylinder frame has the material characteristics of very small elongation and different strength in tension and compression. Based on such an material characteristics, the strength evaluation of cylinder frame was carried out with in-house program developed internally.

• Journal of Advanced Navigation Technology
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• v.6 no.2
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• pp.158-167
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• 2002

In this paper, it is analyzed that WAP packet transmission time to improve performance of WAP using SAR-QT algorithm in Bluetooth channel. The order for SAR-QT algorithm to improve the transfer capability, it is fragmented in WTP total messages that are coming down from upper layer and then the packets are sent one at time in baseband. And it is studied that transmission time for WAP over Bluetooth according to DMI, DM3 or DM5 packet type using SAR-QT algorithm in Bluetooth piconet environment. This SAR-QT algorithm decreases WAP packet transmission time of L2CAP baseband packets by sending packet that are spanning multiple slots. From the results, in WAP over Bluetooth channels, it is found out that WTP packet size ought to be increased to decrease transmission time of WAP packet. In addition, considering BER in wireless channel, optimal WTP packet size is achieved for WAP over Bluetooth in a Rician fading environment.