• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.2
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• pp.194-201
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• 2008

In the present study, fuel system matching was analyzed, and a characteristic chart for common use for design-related parts is presented. Based on the characteristic chart thus presented, controlled fuel system matching was tested for a 35-liter fuel system, and actual mass product movement coils were applied to validate the test. The keynote of the present research is the use of the characteristic chart to devise a preferred fuel system matching method. Through the present study, it will be possible to design standard parts for efficient fuel system matching in the near future.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.45-50
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• 2013

This paper presents design of induction motor in very low temperature for LNG main cargo pump and comparison of two motors. One is the motor for using in room temperature and another is the motor for using very low temperature. This paper designs with Equivalent circuit Method and uses Finite Element Method to analysis. The motor for very low temperature considers variation of coil resistivity due to temperature change and compare torque characteristic with the motor for room temperature. Design element of motor for very low temperature considers resistivity variation following temperature change on going through this paper. The result shows that two types of motors are almost same torque curve characteristic even though they are not the same environment.

• Journal of the Korean Institute of Telematics and Electronics
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• v.3 no.1
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• pp.12-17
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• 1966

A more extensive theoretical analysis for a ferrite filled electromagnetic delay line of two coaxial anisotropic conducting cylinders was made and improvements of the delay line n=0 mode operation was achieved by separating effective sections using short-circuited coils to eliminate unnecessary couplings among windings of different phase. Time delay of order of 10 microseconds per meter in video frequency range was observed from 3"/8 diameter 6" long delay line tilled with ferrite material. Design formula was presented with illustrative discussions to help design for practical purposes. purposes.

• Journal of Applied Reliability
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• v.11 no.1
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• pp.31-41
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• 2011

A strut mount is an important part of vehicles which reduces the vibration and the impact transmitted from the wheels while supporting a shock absorber and a coil spring. Rubber compounding, shape design, and process design technologies are important components to improve the functionality of a strut mount such as durability, static, dynamic, and torsional characteristics. Among them the rubber compounding technology is the key technology which dominates the quality of a strut mount. In this study a strut mount with high reliability has been developed by adopting new rubber compounding and improving the shape of the inner plate and the isolator. Through the tests for prototypes it has been shown that the durability has been improved more than 2.5 times, from about 60,000 cycles to about 160,000 cycles.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.484-490
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• 2000

The freight wagon with weld fabricated 1-piece bogies, which was developed to increase operating speed, reveals its difficulties in maintenance. The weld-fabricated bogies were composed of two-stage coil spring and dry friction damping mechanism. The inborn wear parts and rather complicated structure mattes bogie maintenance difficult. In order to relieve this difficulties, the application of maintenance free rubber suspension is proposed by bogie maunfacturer, Taeyang Precision Limited. This study was conducted to determine design parameters of proposed rubber suspension by means of vehicle dynamic simulation and parametric study. The target critical speed of bogie was set over 150km/h for the preparation of further speed-up of freight wagon.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.27-34
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• 2000

HTS wires processed by PIT method are now available for magnet applications. But, those wires can not be used over 40 K due to weak link. This leads to necessity of development of coated conductor which can retain high $J_c$ at high field in liquid nitrogen. In this paper, various technical issues and the R&D status for both PIT wires and coated conductor were discussed. The difference of coated conductor's processes were also investigated and summarized. Various requirements for a design of HTS magnets were discussed. Anisostropic $J_c$ property with respect to magnetic field was considered to determine the coil's critical current. Low n value is a critical parameter to degrade a field stability with respect to time for a persistent mode HTS magnet. The relation between the margin of operation current and n value was investigated. Prototype HTS magnets with PIT wires are being developed for various applications such as crystal growth, MRI, magnetic separator and etc. HTS magnets will come into wide use in various fields of industries if the HTS wires with a low performance cost is developed.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1114-1115
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• 2015

This paper describes the design of toroid-type HTS DC reactor magnet. Target operating current and inductance of the HTS DC reactor are 1,500 A and 400 mH, respectively. The HTS DC reactors were designed through electromagnetic analysis and 3D CAD program. And, we analyze the operating performance of the Double Pancake Coil module for the 1,500 A, 400 mH HTS DC reactor magnet under the liquid nitrogen condition.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.685-686
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• 2015

This paper describes design results of the measurement system to test the properties of broadband AC magnetic field sensors used in weapon system. This measurement system consists of 3-axis helmholtz coil, signal generator, signal amplifier, sensor data acquisition unit and measurement & analysis controller including the operating software. This system is able to measure various properties of AC magnetic field sensor such as sensitivity, linearity and dynamic response in the frequency of 1 Hz to 10 kHz. The performance of this system was verified by measuring and analyzing the property of a MAG 639, standard magnetic field sensor of bartington instruments, with this developed system.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.12
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• pp.587-591
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• 2001

This paper describes the general and efficient design method of an axial and a radial shim coils to correct field impurities of various harmonic orders in the imaging volume of Magnetic Resonance Imaging magnet. Shim coils are optimized by BCLSF subroutine of IMSL, which is the well-known commercial package for optimization, aiming at maximizing the magnitude of the desired field component as well as minimizing other field components. In order to evaluate their effect, the developed method was applied to the MRI magnet constructed in KERI.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.43-51
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• 2010

Speed, accuracy and smoothness are the important properties of pan-tilt camera. In the case of a high ratio zoom lens system, low vibration characteristic is a crucial point in driving pan-tilt mechanism. In this paper, a novel micro-stepping controller with a function of reducing vibration was designed using field programmable gate arrays (FPGA) technology for high zoom ratio pan-tilt camera. The proposed variable reference current (VRC) control scheme reduces vibration decently and optimizing coil current in order to prevent the step motor from occurring missing steps. By employing VRC control scheme, the vibration in low speed could be significantly minimized. The proposed controller can also make very high speed of 378kpps micro-step driving, and increase maximum acceleration in motion profiles.