• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.397.2-397
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• 2002

There are 4 servo systems in a DVD drive such as a focus servo system, a tracking servo system, a sled servo system and a spindle servo system. Focus servo system maintains relative distance between lens and disk. In this paper, two plant models for the focus servo system will be presented. One of them is newly developed and the other is conventional. Focus error signal between lens and disk is detected using LDV 2 beam method. (omitted)

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.71-74
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• 2007

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate vibration and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.47-54
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• 2006

To improve passenger safety, seat belt systems with pre-tensioner that tightens seat belt webbing using explosive just before collision are widely used these days. Even though seatbelt must not unlatched without passengers' operation. explosive power of pre-tensioner can cause unlocking of a buckle. To prevent the unlocking, an anti-g mass that blocks displacement of the release button has been attached to the buckle. In this study, the dynamics and statics of locking mechanism associated with operation of anti-g buckle has been theoretically investigated, and important design variables that affect the operation of anti-g buckle have been identified. Through the total seat belt system's dynamic simulation using force and displacement inputs obtained from seat belt sled test, design of the proposed anti-g buckle has been validated.

• Ocean Science Journal
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• v.42 no.3
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• pp.171-178
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• 2007

The present study reports mysids on sandy beaches along the eastern coast of Korea. Samples were collected with a dip net or a sled net in sandy shores in April 1995 and November 2006. 9 species representing five genera were identified from the present study. Of these, the genus Nipponomysis including N. lingvura, N. ornata, and N. imparis, and Acanthomysis nakazatoi were newly recorded from the Korean waters. Morphological descriptions and taxonomic key to species were given. The present study reports that 45 species belonging to 15 genera from the Korean waters have been recorded.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.172-182
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• 2000

A hybrid type automotive drivers seat was invented with new concepts for the reduction of weight and manufacturing costs. Fundamental studies were performed to determine the basic geometry of reinforcing support. A prototypical design was provided by the manufacturer considering compatibility with other parts. Several structural analyses simulating various crash situations were performed and modifications were continued until a final design was reached. A sample product was manufactured and sled crash tests were performed to verify the safety of the seat. Comparisons of test results with the previous model and a seat from another company proved safety performances to be superior.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.139-150
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• 2000

Although a number of neck injuries are generated, the data which quantify the kinematic response of the human head and cervical spine in low-speed rear-end automobile collisions is very limited. On this problem, just few in vitro experimental research or some experimental research using dummy on neck injury by rear-end collision was conducted, thus systematic research is requested on full scale injury mechanism. An occupant model for the response of the occupant subject to rear-end collision using commercial dynamics package DADS was developed. Developed model shows more close agreement with the experimental data compared with the MADYMO simulation results for the cases of ${\delta}V=16$ kph in sled test. For the case of ${\delta}V=8$ kph and 33.5 kph with production seat, model also shows its reliable response compared with experimental results using Hybrid III and Hybird III with RID.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.2
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• pp.62-76
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• 1995

The safety analysis becomes very essential in the crash environment with the growth of automobile industry. Recently, an airbag system is required to protect the occupant. The effects of an airbag can be evaluated exactly from the barrier or sled test which is quite expensive. The airbag system in a passenger car is analyzed with the occupant analysis program. The modeling of the passenger car including an airbag is established and the results are verified by comparisons with real crash tests. However, the solution of an airbag design can not be obtained easily with the conventional method such as an optimization due to the nonlinearity and complexity of the problem. An iterative design algorithm using the orthogonal array is proposed to overcome the difficulties. The design trend of an airbag is recommended to minimize the injury of an occupant with the proposed design algorithm and the results are discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.4
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• pp.266-275
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• 2008

The performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle has been focused so far. However, for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module and vehicle level. The test procedure to evaluate vibration and collision safety of high pressure hydrogen storage system for the fuel cell vehicle is established and its reliability is verified.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.103-105
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• 1994

A novel structure of a lineal microactuator has been designed and analyzed. The proposed structure can overcome serious problems from which conventional linear microactuators suffer, primarily due to the moving principle that is the repetition of attachment and detachment of the moving part to the fixed part. According to the calculated results, the proposed microactuator can generate force of a few mN and the moving sled of 13 cm/min under the condition of 100 volts and the frequency of 1.4 kHz.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.57-63
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• 1997

In this paper we report test results of the dynamic characteristics of the linear induction motor(LIM) used for propulsion of the UTM-01. To test a vehicle scale LIM, we manufactured a bogie type sled propelled by LIM. In this report, the LIM end effects for both cases when the vehicle is at rest and when the vehicle is running were measured and compared with the calculations. The LIM thrust and the vertical forces were measured by the 3-component load cell and the results were compared with the calculations from measured vertical load and vehicle velocity.