• Journal of Korean Society for Quality Management
• /
• v.31 no.4
• /
• pp.226-238
• /
• 2003

Recently, The problems with which our country's company is confronted for business of manufacturing goods. This study set the hypothesis to develop the method that was analysis and application of A reliability evaluation method of environmental material for circuit components in Computer, Color TV, Monitor, Microwave oven, Electric Refrigerator, Automobile parts, other goods. Especially, this study emphasis on regulate export of the EU and North America that it's a environmental material's hazards problem. In this process, this study set the pattern of practical application. Therefore, this study emphasis on the application of A reliability evaluation method of environmental material and the use of other parameters by environmental reliability test data. The result of this study is as follows. 1) There is relationship between regulate material and technical protecting system. 2) Characteristics of hazard materials is operating a healthcare damage factor as well as regulate environmental factors.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1514-1517
• /
• 2005

In recent years, as the demands of VBNS(Very high speed Backbone Network Service) and VDSL(Very high-data rate Digital Subscriber Line) increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, WDM elements increase. The alignment and the attachment technology are very important to fabricate the optical elements for communication. In this paper, the mechanism of rotational stage are studied. with the three different method and the results of them are applied to the design of the system. The performance test of resolution and travel is performed.

• The Journal of the Acoustical Society of Korea
• /
• v.18 no.1
• /
• pp.92-96
• /
• 1999

As CMOS technologies have been rapidly developed, bridging faults have been relatively increased. IDDQ testing is a current testing methodology which can enhance reliability of the circuit since it efficiently detects bridging faults that are difficult to detect by functional testing. In this paper we consider internal bridging faults occurred in each gate of logic circuits under test and finally develop a fault simulator for IDDQ testing to detect assumed bridging faults.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.3
• /
• pp.81-86
• /
• 2005

The agricultural working tractor of this study is equipped with 4 wheel driving system developed in study 1 and 4-type wheel steering system. The wheel steering system has four type of steering methods that are front wheel steering, rear wheel steering, 4 wheel steering with opposite phase, and 4 wheel steering with corresponding phase. This study introduces the hydraulic circuit of the 4-type wheel steering system and the construction of working tractor. Judging from the field test results of the developed working tractor, it is apparent that 4-type wheel steering system has many advantages when driving in a narrow corral.

• Journal of Power Electronics
• /
• v.14 no.6
• /
• pp.1217-1223
• /
• 2014

A novel half load-cycle worked dual input single output (DISO) DC/AC inverter is presented. The basic circuit consists of a dual buck regulator, which works in continuous current mode. The working principle of DISO DC/AC inverter has been used. The control method applied for half load-cycle worked DISO DC/AC inverter has been studied. The control effects of the open-loop proportional control and closed-loop proportional-integral control are compared by using PSIM software. The parameters are adopted in the realistic simulation and experiment test. Moreover, the waveforms, such as voltage of modulation reference signal and output voltage, were given. The simulation and experiment results proved that the half load-cycle worked DISO DC/AC inverter could achieve good performance, gain a line frequency of 50 Hz, and verify the correctness of theoretical analysis.

• Proceedings of the KIEE Conference
• /
• 1987.07b
• /
• pp.1488-1491
• /
• 1987

This paper describes 16-point FFT processor using systolic array and its implementation into VLSI. Designed FFT processor executes FFT/IFFT arithmetic under mode control and consists of cell array, array controller and input/output buffer memory. For design for testibility, we added built-in self test circuit into designed FFT processor. To verify designed 16-point FFT processor, logic simulation was performed by YSLOG on MICRO-VAXII. From the simulation results, it is estimated that the proposed FFT processor can perform 16-point FFT in about 4400[ns].

• Proceedings of the KIEE Conference
• /
• 1998.11c
• /
• pp.929-931
• /
• 1998

The tracking characteristics of silicon rubber degraded by accelerated outdoor exposure employing a weather-o-meter have been investigated. The tracking test was performed according to IEC Publ.587 but the concentration of conductive material was two times higher than the IEC standard in order to accelerate the tracking failure. The number of large effective scintillation and the current of high voltage circuit were measured by changing two signals as voltage signals. It was fiund that the increase of exposure time resulted in the reduction of tracking resistivity except the fact that the specimens slightly degraded within 200 hours has slightly increased the duration time.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.821-824
• /
• 2005

This paper presents a technique to evaluate torque and speed characteristics of induction motor with the Dynamometer. The simple Dynamometer controlled via microcontroller and displayed by computer. The Microcontroller generates the PWM (Pulse Width Modulation) signal and control the duty cycle of signal for control braking level. The Buck converter is a braking unit which uses IGBT as switch in circuit. The output current of the Buck converter and output voltage of tacho generator are converted to digital signals and analyzed by microcontroller. The signals are then sent to computer for displaying torque and speed responds independent on the braking time. The test results of the Dynamometer in this research can coreectly predict the torque and speed response under reasonable tests. Moreover, this Dynamometer is easy and inexpensive to make.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.1
• /
• pp.48-55
• /
• 2003

The design and analysis of a three-phase 6/8 structure SRM(switched reluctance motor) art described. The range of the stator ole arc and the rotor pole arc of the motor we analyzed in the linear region. The optimum range of the stator pole arc and the turn-off angle of the main switches in the power converter are given with the 2-D finite element electro-magnetic field calculation of the motor and the nonlinear simulation. Test results of the prototype are discussed. This type is good for high efficiency drive because the drive circuit is simple and current density and copper loss of the winding are law.

• Journal of electromagnetic engineering and science
• /
• v.15 no.4
• /
• pp.258-265
• /
• 2015

A de-embedding method for multiport networks, especially for coupled odd interconnection lines, is presented in this paper. This method does not require a conversion from S-parameters to T-parameters, which is widely used in the de-embedding technique of multiport networks based on cascaded simple two-port relations, whereas here, we apply an operation to the S-matrix to generate all the uncoupled and coupled coefficients. The derivation of the method is based on the relations of incident and reflected waves between the input of the entire network and the input of the intrinsic device under test (DUT). The characteristics of the intrinsic DUT are eventually achieved and expressed as a function of the S-parameters of the whole network, which are easily obtained. The derived coefficients constitute ABCD-parameters for a convenient implementation of the method into cascaded multiport networks. A validation was performed based on a spice-like circuit simulator, and this verified the proposed method for both uncoupled and coupled cases.