• Journal of the Korean Magnetics Society
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• v.4 no.2
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• pp.106-113
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• 1994

This paper deals with the magnetic forces of the combined levitation and guidance EDS(Electrodynamic Suspension) maglev system when the car bogie is tilted by the roll, pitch and yaw. The end effect on the magnetic forces are considered by calculating the air-gap flux without the assumptions for its pattern. Induced voltages and currents of the ground coils are given as results. The restoring torque due to roll, pitch and yaw of the bogie body are also examined. It has been shown that the end effect of the concentrically loaded vehicle are not negligible and the combined EDS is stable maglev system against disturbing forces.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.247-250
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• 2006

The growing demand for more fuel-efficient vehicles to reduce energy consumption and air pollution is a challenge for the automotive industry. The characteristic properties of aluminum, high strengrth stiffness to weight ratio, good formability, good corrosion resistence, and recycling potential make it the ideal candidate to replace heavier materials in the car to respond to the weight resuction demand within the automotive industry. In this paper, A series of compression test was carried out to find the flow stress of A6082 at 300, 400 and $500^{\circ}C$, then we tried to estimate weldability, extrusion load and effective stress of die in the aluminum extrusion process through the 3D FE simulation at non-steady state for aluminum automotive parts.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.455-460
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• 2006

본 논문에서는 자속 궤환을 포함하는 자기부상 시스템의 open-loop 특성에 대해서 다룬다. 훌륭한 외란 억제 특성을 포함하고 파라메타 변동에 대해서 둔감한 제어기를 설계하기 위해서 자속 궤환을 이용하는 것이 효과적일 수 있다. 적절한 센서에 의해서 측정 가능한 자속은 전류와 공극의 시간 변화에 대해서 선형적인 관계를 가지고 있으며, 자속의 궤한은 자기 부상시스템이 본질적으로 갖고 있는 전기적 엑츄에이터와 기계적 플랜트 사이의 간섭에 의해서 발생하는 비선형성을 감소시키는 역할을 한다. 모의시험 결과를 통해서 자속의 궤환이 자기부상 시스템의 부하변동에 대해서 Open-loop 성능 향상에 효과적임을 보인다.

• Journal of KSNVE
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• v.9 no.1
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• pp.97-102
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• 1999

Structure-borne noise is an important aspect to consider during the design and development of a vehicle. In this work. it was desired to identify the primary paths associated with structure-borne noise generated from the engine and front suspension. An experimental source-path-receiver model was used to characterize the system. A variety of primary sources such as engine. tires or exhaust system generate vibrations of the inner surfaces of the passenger compartment of a vehicle which subsequently radiate noise. The source was characterized by the force acting at the engine-to-body interface. and the path was characterized by pressure over force FRF's. The excitation forces were indirectly determined using dynamic stiffness of rubber mount or the system accelerance matrix. Through these analysis, path contribution diagram which is well expressed primary noise path is obtained.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.163-167
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• 2003

In this paper, an air-suspension type RF MEMS inductor is fabricated, and an appropriate de-embedding scheme for 3-dimenstional MEMS structure is applied and verified with inductance calculation algorithm. With the presented de-embedding method, parasitics from contanct pads and feeding lines are effectively and accurately de-embedded using open and short calibration procedure, and only spiral and posts can be characterized as a high-Q inductor structure. The validity of the de-embedding method is verified by the comparison of the measured and calculated inductances of two 1.5 and 2.5 turn square spiral inductors. The open-short de-embedded inductance error is below 5% each case in comparison with the calculated value based on H.M. Greenhouse's algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.1-8
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• 2000

Automotive electronics as we know it today encompasses a wide variety of devices and systems. Key to them all, and those yet to come. is the ability to sense and measure accurately automotive control parameters. In other words, sensors and actuators are the heart of any automotive electronics application. The important of sensors and actuators cannot be overemphasized. The future growth of automotive electronics is arguably more dependent on sufficiently accurate and low-cost sensors and actuators than on computers, controls, displays, and other technologies. Without them, all of controls system - engine. transmission. cruise, braking, traction, suspension, steering, lighting, windshield wipers, air conditioner/hearter - would not be possible. Those controls, of course, are key to car operation and they have made cars over the years more drivable, safe, and reliable. In this lecture, the principle and future trends of electronic control gasoline engine will be discuss.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.60-61
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• 2001

To produce reconstituted rabbit embryos with fetal fibroblasts, the present study was evaluated the efficiencies of the activation conditions as assessments of subsequent development and chromosome in the embryos. New Zealand White rabbits were used throughout the study. Fetal fibroblasts collected from 22-d of fetuses were cultured in DMEM＋10% FBS in 5% CO₂ in air. The culture was maintained for 10 passages. In every passage half of cell suspension were kept in frozen. (omitted)

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.774-777
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• 1988

This paper covers the insulation coordination of 765 KV transmission line in Korea Electric Power Corporation. The design for the lightning, switching surge, and contamination was conducted to increase the reliability of 765 KV line. The authors have used the result of a limited Westinghouse ANACOM swiching surge study of the Korea Electric Corporation's 765 KV Expansion plan. The study investigated the switching surge overvoltage distribution and maximum switching overvoltage when relosing 765 KV lines. They used the technical data of the suspension insulator for the contamination design, which was available from a foreign insulator manufacture. From this paper, the authors find out that the contamination design dominates to determine the number of insulator and the SOV design dominates the air clearance in the tower. Afterwards the authors will confirm this design by Demonstration Test with Korea Electro-technology Research Institute.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.288-293
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• 2005

The pressure distribution and heat transfer coefficient were measured at room temperature in the high suspension density CFB heat exchanger with multiple vertical tubes and the effective density of CFB was determined. The theoretical model for predicting heat transfer coefficient was developed in this study. The model predictions were compared with the measured heat transfer coefficient to show relatively good agreement between them.

• Transactions of Materials Processing
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• v.11 no.7
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• pp.620-627
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• 2002

The purpose of this paper is the development of an automated measurement system for micro spring based on the digital image processing technique. This micro spring can be used in various engineering applications such as filament, load bearing springs, hard disk suspension and many others. Main functionality of the micro spring inspection system is to measure the representative pitch of the micro spring. The derivative operators are used for edge detection in gray level image. Measurement system developed in this paper consisted of new auto feeding mechanism to take advantage of air pressure. In the process of development of the micro spring inspection system based on the image processing and analysis, strong background technology and know-how have been accumulated to measure micro mechanical parts.