• Journal of electromagnetic engineering and science
• /
• v.9 no.3
• /
• pp.159-163
• /
• 2009

This paper presents the design and implementation of Q-band MMIC phase shifters using InGaAs PIN diodes. The topology using a thin-film microstrip line(TFMS) has been proposed to achieve the desired phase-shift as well as good loss characteristics. Five single-bit MMIC phase shifters have been implemented by using a developed BCB(benzocyclobutene)-based multi-layer fabrication technology. The developed phase shifters have less than 3.4 dB of insertion loss and better than 11 dB of input and output return loss in the frequency range of 43 to 47 GHz. To the authors' knowledge, this is the first demonstration of high-performance InGaAs PIN diode-based MMIC phase shifters operating at Q-band frequencies.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.966-970
• /
• 2005

On the basis of the development of KSLV-1, KoDSat was designed and manufactured to demonstrate the performance of KSLV-1. KoDSat is exposed to a severe vibrational environment at launch. The structural reliability of KoDSat has to be verified using vibrational test. The structural compatibility and verification of components between analysis and test can be proved using environmental vibration test. In this paper, we review the structural characteristic of thruster control unit for a space launch vehicle and design TCU housing using mathematical model. In order to verify the structural compatibility and reliability, half-sine shock, random and sing sweep vibration test was performed. Especially, sing sweep vibration test result is compared with analysis result and mathematical model is verified.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.11a
• /
• pp.684-687
• /
• 2005

KIER has been running a demonstration project for 10kWe solar thermal power generation. the project is to build and operate the first solar thermal power generation system in Korea. For concentrating solar thermal energy $40m^2$ dish type concentrator was adapted and a stirling engine is going to be integrated to the system for power production. At the moment building the dish concentrator including mirror and sun tracking system was completed and it's performance are being closely evaluated. This paper will introduce some detailed designs and construction procedures which we have experienced so far.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.569-572
• /
• 1995

In this study, a hydraulic modulator of solenoid-flow type ABS, the master sylinder, and the wheel cylinder are modeled and simulated for increasing pressure characteristics of the brake. Response can be predicted by external force of the the master sylinder and pulses to the solenoid valve as input. For a demonstration of simulation result, experiment is done under the same condition as simulation condition after experimental apparatus of 1/4 car model is constructed. When factors of flow control valve are changed, the effect of each factor to response, how to improve response, and the most critical factors are considered from simulated result of time constant.

• International Journal of Precision Engineering and Manufacturing
• /
• v.2 no.1
• /
• pp.5-10
• /
• 2001

A method is proposed to obtain the Jacobian matrix of the 5 -bar parallel manipulator by employing the orthogonality between position and velocity vectors of rotating rigid-body around a fixed point. The dynamics of the 5-bar parallel manipulator is analyzed and utilized to design the computed-torque controller by developing a transformation matrix of the passive joints with respect to the active ones. In experimental demonstration, it shows that high-speed and accuracy tasks are performed by the proposed computed-torque control.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.697-699
• /
• 2005

High temperature superconducting (HTS) cable could be regarded as one of the most promising technologies for large electric power delivery with high reliability and low losses of power transmission system. Therefore, since 2001, LS Cable Ltd. has been developing 22.9kV, 50MVA HTS cable system as a member of DAPAS (Dream for Advanced rower system by Applied Superconductivity technology) program. In 2003, 22.9kV HTS cable system, single-core cable employing BSCCO HTS wires was firstly manufactured in 2003, and then three-core cable was also successfully developed through the demonstration of its field applicability. In this paper, based on these experiences, the relevant design technology and transient characteristics of HTS cable is described.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.05a
• /
• pp.190-193
• /
• 2004

Ever since the ideal forming theory has been developed fur process design purposes, application has been limited to sheet forming and, for bulk forming, to two-dimensional steady flow. Here, application for the non-steady case was performed under the plane-strain condition based on the theory previously developed. In the ideal flow, material elements deform following the minimum plastic work path (or mostly proportional true strain path) so that the ideal plane-strain flow can be effectively described using the two-dimensional orthogonal convective coordinate system. Besides kinematics, for a prescribed final part shape, schemes to optimize a preform shape out of a class of initial configurations and also to define the evolution of shapes and boundary tractions were developed. Discussions include the two problematic issues on internal tractions and the non-monotonous straining. For demonstration purposes, numerical calculations were made for a bulk part under forging.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2748-2750
• /
• 1999

This Paper describes the design of an induction motor control using the TMS320C32 Digital Signal Processor and the ADMC201 motion coprocessor. Presented hardware architecture can be used for several industry applications with wide range of speed control, e.g. elevator and cranes application, servo motor, electrical vehicles. The main purpose of the paper is demonstration of the implementation and maximum utilization of the ADMC201 motion coprocessor in digital vector control system for AC drives.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.78-80
• /
• 2005

Haptic interface apparatus is the device which can offer users virtual reality not only by visualization of virtual space but also by force or tactile feedback. In this paper, we designed and fabricated a 2D haptic interface device that can be used for various purposes, and implemented a virtual air-hockey system that users can easily find in game rooms. By suitable modeling and haptic rendering, users can feel the impact and the reaction force with his/her hand holding the handle through 2D haptic interface device when he/she hit an air-hockey puck with the handle. Through the trial demonstration. we observed the reasonable effect of direction and speed of a ball like doing in reality.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.73-78
• /
• 2003

Ultrasonic measurement is one of important technologies in the lift-time maintenance of nuclear poler plant. Ultrasonic inspection system is consisted of the operator, equipment and procedure. The reliability of ultrasonic inspection system is affected by its ability. The performance demonstration round robin was conducted to quantify the capability of ultrasonic inspection for in-service. The small number of teams who employed procedures that met or exceeded ASME Sec. XI Code requirements detected the piping of nuclear power plant with various cracks to evaluate the capability of detection and sizing. In this paper, the statistical reliability assessment of ultrasonic nondestructive inspection data using Monte Carlo simulation is presented. The results of the probability of detection (POD) analysis using Monte Carlo simulation are compared to these of logistic probability model. In these results, Monte Carlo simulation was found to be very useful to the reliability assessment f3r the small hit/miss data sets.