• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.4 s.235
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• pp.614-623
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• 2005

This study aims to perform the characteristic evaluation of surface grinding for the STD11 material with experimental and analytic techniques based on the response surface model. The grinding force acting on the workpiece and the ground surface roughness were measured according to the change of grain size, table speed and depth of cut. The effect of spark-out on the grinding force and the surface roughness was also characterized. The frictional coefficient between workpiece and grinding wheel could be determined by the analysis of spark-out effect. From the experimental data, the second-order response surface models were developed to predict the grinding force and the surface roughness. Validation of the developed model was examined.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.3
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• pp.210-216
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• 2015

This paper proposes a method to determine vehicle driving state using the driving characteristics index. This index is a quantitative value to classify the driving state of a vehicle with its velocity and heading angle in that instant. It can classify driving state into straight driving, lane changing driving and curve driving in real time. In addition, the number of positional information is movably set up by designed region of interest. The proposed index is expressed on the stable driving states. Each driving state has characteristic tendency, and is compared with index distributional areas. The proposed method is verified by the actual driving experiment on the KATECH proving ground.

• Journal of Ocean Engineering and Technology
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• v.16 no.1
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• pp.41-45
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• 2002

This paper is concerned with the erection and ultimate load test of dome shaped space structures by post-tensioning. It is a fast and economical method for constructing such a dome by post-tensioning of the cable in bottom chords. This structure consists of uniform pyramids in a flat layouts on the ground, and then the structure is shaped and erected into its final curved space structure. Ultimate load test was performed for dome shaped space structures. The feasibility of the proposed erection method and the reliability of the established geometric model were confirmed with numerical analysis and experimental investigation on a small scale steel model. As a results we can find the most reasonable modeling technique for the prediction of shape formation in practices and we can know the characteristic of the behaviour in ultimate load test for practical design purposes.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.18-22
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• 2014

A new concept tractor is developed, which can conduct multi-functional complex tasks such as excavating and working with attached various equipments. A cabin of the agricultural tractor is designed to protect the driver from vibration transmitted due to the irregular ground and overturning of the tractor. In this paper, the dynamic characteristic of the cabin is identified through finite element analysis and effects of configurational parameters are investigated to insure the dynamic stiffness of the cabin.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.10
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• pp.487-495
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• 2005

This paper reviews the characteristic of thermal and temperature of oil field cable in transient state such as grounding fault and lightning surge. For analysis in various conditions, many actual underground power cable systems are modeled using ATP. These results are applied for the examination of temperature increase when the single line to ground fault by the breakdown of insulation part and hitting of lightning surge are occurred. The inner part temperature of OF cable is analysed according to the various kinds of cable using the thermal model of transient state. The temperature increase of sheath and crossbonded lead bv fault current is also analysed using IEC 60949.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.494-496
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• 2003

This paper analyses the operation characteristic of distance relay when the single line to ground occurs in underground power cable systems that reduction device of sheath circulating current is installed. To apply that reduction device to actual system, the change of line impedance calculated at relay point is also analysed by the connection type of SVLs and fault location, fault inception angle with the installation of reduction device of reactor or not.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.77-78
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• 2007

A planar UWB antenna using partial ground and CPW feeding is designed and fabricated. We obtained the return loss of average -8.2 dB in Low Band ($3.1\;GHz{\sim}4.8\;GHz$) and the good band rejection characteristic in the range of $4.9\;GHz{\sim}6.8\;GHz$. The simulation results by HFSS are seen to be in good agreement with the measured results.

• Journal of the Korean Professional Engineers Association
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• v.44 no.4
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• pp.44-49
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• 2011

For the pleasant dwelling place, the most of apartments are designed with the increased green area ratio in ground space and the underground parking lot. However, the condensation in underground space has occasionally occurred due to the insufficient ventilation and insulation treatment. Despite reinforcement of the insulation treatment and mechanical ventilation for the preventing method of condensation. It seems difficult to expect preventing effects for the condensation without consideration of the thermal characteristic of structures. Furthermore, no fundamental measure has been established because maintenance work for these defects incurs a lot of costs and these defects could be occurred again. This study suggests a new method for preventing floor surface condensation through analyzing the reasons of condensation which occurred in the underground floor.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.2
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• pp.105-112
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• 1990

Advanced ceramics have some excellent properities as the material for the mechanical component. It is, however, very difficult to grind ceramics with high efficiency because of their high strength, hardness and brittleness. In this paper, some experiments are carried out to find the basic grinding characteristic of advanced ceramics. Representative advanced ceramics, such as AL/sub 2/ O/sub 3/, ZrO/sub 2/, SiC and Si/sub 3/N/sub 4/and ground with diamond wheels. Special attention is paid to comparison between the conventional and creep feed grinding. Results obtained in this study provide some useful informations to attain the high efficiency grinding of advanced ceramics.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.75-83
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• 2001

In this paper, numerical analysis is used to find the effects of inclination of rear end on flow characteristic around an automobile. The reference slant angle of rear end is 28.6$^{\circ}$, the slant angle of rear end is decreased to 24$^{\circ}$, 26.6$^{\circ}$ and also increased to 31.6$^{\circ}$, 36.4$^{\circ}$. The 3-D incompressible Navier-Stockes equations are solved by the iterative time marching scheme. The computed surface pressure coefficients were compared with experimental results and a good agreement has been achieved. The A- and C-pillar vortex and other flow phenomena around the ground vehicle are evidently shown. The variation of aerodynamic coefficients of drag, lift with respect to inclination angle of rear end are systematically studied. The flow characteristic on the automobile surface with respect to change of inclination of rear end have been also studied.