• Journal of Magnetics
• /
• v.22 no.2
• /
• pp.266-274
• /
• 2017

In this paper, torques of two motors are compared by Finite Element Analysis (FEA). One has a symmetric rotor structure and the other has an asymmetric rotor structure. The comparison shows that the asymmetric rotor structured motor has reduced torque ripple compared to the symmetric. The torque of the compared motor models was analyzed by separating into magnetic torque and reluctance torque. Through the analysis of torque component separated, it is shown that the magnetic torque and the reluctance torque compensate each other in the motor with the asymmetric structure rotor. Here "compensate" means decrementing the effect of one or more harmonics. It is shown how this compensation appears between the magnetic torque and the reluctance torque by looking into back electro motive force (emf) and the relative permeability distribution of rotor core.

• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.1
• /
• pp.15-20
• /
• 2002

In this project, we hale developed various techniques for subminiaturization, surface implementation, high frequency design, small-size SMD, performance test and application of the Dual PLL module, which is a core component for the personal communication systems. We also obtained base techniques for the next-generation Dual PLL module design and fabrication techniques for an internationally competitive subminiature Dual PLL module.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.870-875
• /
• 2004

In Japan, a long-waited civil aero engine development project has been recently started by the New Energy and Industrial Technology Development Organization, NEDO. “High efficiency,” “environmentally friendliness” and “low-cost” are the key words of the target engine. The target engine is of l0000-lb thrust with project consists of three phases: Feasibility studies and market research in the first phase, FY 2003, engine component development in the second phase, FY 2004-2006, and core and full engine demonstrators in the third phase, FY 2007-2009. In league with this government/industry joint funded project, Institute of Space Technology and Aeronautics, JAXA, has initiated “Clean Engine Technology” project.

• YAKHAK HOEJI
• /
• v.47 no.2
• /
• pp.104-109
• /
• 2003

The present paper reviews the notion and comparison of the Korea Food and Drug Administration(KFDA) general pharmacology and the International Conference on Harmonisation (ICH) safety pharmacology. General pharmacology or safety pharmacology is termed the study to determine the potential of a compound to induce adverse pharmacological effects. KFDA general pharmacology studies have been considered an important component in drug safety assessment and these were originally referred to those designed to examine effects other than the primary therapeutics effect of a drug candidate. The KFDA notified the Guideline for General Pharmacology in 1997. Safety pharmacology studies were focused on identifying adverse effects on physiological functions. In the ICH came into place S7A Safety Pharmacology Studies for Human Pharmaceuticals in 2001. A new chemical entity should be assessed for its side effects, initially in those physiological systems which are generally agreed to be the key systems that are essential for life; these "core system" include the central nervous system, cardiovascular system and respiratory system in safety pharmacology studies. These studies should be performed in compliance with Good Laboratory Practice (GLP).

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.1172-1177
• /
• 2006

Effective management strategies of railroad environment should be prepared by the systematic management with the environment core technologies from the initial stage of the railroad environment to provide energy-efficient, safe, sound, and environment-friendly railroad service. In addition, the need for the development of railroad environment policy, like the improvement strategies and development strategies of railroad environment, is strongly required to actively prepare for the strengthening of environment regulations and supervision on the railroad environment problems. In this research, we studied the correlations between railroad environment policies and management strategies, and defined the component of environment policies. Moreover, we tried to present the direction of environment policies and mid-/long-term development plans that suit for the characteristics of Korean railroad through investigating the environmental policies of advanced countries.

• Proceedings of the KIEE Conference
• /
• 2003.11a
• /
• pp.210-212
• /
• 2003

Conventional PDC relaying with 2nd harmonic restraint makes some doubt in reliability. It can contain second harmonic component to a large extent even during internal fault, and shows a tendency of relative reduction because of the advancement of transformer's core material. It is, therefore, necessary to develop a new algorithm as well as a new technique for the effective and accurate discrimination. This paper deals with advanced algorithm, fuzzy logic based relaying by using flux differential, and a new fault detection criterion logic scheme by using wavelet transform. To comparative analysis of proposed techniques, the paper constructs power system model including power transformer, utilizing the EMTP, and collects data through simulation of various internal faults and magnetizing inrush.

• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.638-641
• /
• 2001

Connectorless power transmission and supply are the power transfer device revealed by resonant inverter or transformer using inductant device. Recently, on power supply have been going on frequently, so several power supply circuit forms are announced. But Compared with the circuit of previous paper, instead of the circuit composed of a simple sylinder Ferrit, I was manufacture in a sylinder that It was a double overlab to a sylinder and I was followed a double flux in inner flux path. Above all, for practicalization, supply circuit operation character analysis and development of controller should be preceded. According to this paper, power transmission and supply analyze characters and design control circuit like the analysis of general resonant inverter for power transmission. They compose the circuit to get sinusoid wave output voltage using pulse width modulation control mode. For Supply, output wave form through power track and power pick-up of magnetic inductance includes ripper component. So I intend to design the controller including filter and regulator, compare analyze theoretical result with real measurement value and then show you their practicality

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.1
• /
• pp.190-195
• /
• 2004

An exhaust brake system is composed of a gate valve, a pneumatic cylinder and an on-off solenoid valve. An on-off solenoid valve which is a key component of the exhaust brake system ought to have characteristics such as high reliability and long life for reducing the foot brake and tires damage, and for driver's fatigue relief of middle/large size vehicles running a long distance. In this paper, an on-off solenoid valve which is used for vehicle brake system was studied. For the performance evaluation of the on-off solenoid, electromagnetic characteristics and dynamic characteristics are analyzed. On the basic study for the performance improvement of exhaust brake system, pneumatic circuit and pneumatic valve of on-off solenoid type were suggested and the performance of pneumatic valve through the test procedure was evaluated.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.6
• /
• pp.771-778
• /
• 2013

Transmission is a core component of helicopter to transmit power from engine to rotor and must have a endurance to be able to show satisfactorily its performance required during its life time. When developing a new helicopter, both military and civil airworthiness authorities require a tie-down test to verify its endurance. Procedure for transmission endurance test is described in FAR part 29 or US military specification but its details are more or less ambiguous. In this paper, we have proposed a proper procedure for transmission endurance test by giving KUH transmission endurance test example including determination of applicable torque, load and test profile.

• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.79-80
• /
• 2014

Voltage source multilevel module converter attracts more and more attention recently. The core component of the voltage source multilevel module converter is the valve based on IGBT. So the test circuit for the valve is very important, reliable test method can guarantee the converter valve design meet the operation requirement. This paper analyzes the valve voltage and current stress during the operation, and according to IEC standard test requirement, object, condition, introduces a kind of test circuit. Finally, through the simulation model, to verify the test circuit can provide the proper test condition for the voltage source multilevel module converter valve.