• Journal of Welding and Joining
• /
• 제20권2호
• /
• pp.71-76
• /
• 2002

Currently knowledge of strain in welds has mainly been obtained from strain gage method; that is directly attaching the gage to the most of the material. The very flew non-contact methods are still in the early stage. One of the non-contact methods is by the use of the laser that has high-level of the accuracy for the measurement, and this laser also has excellent characteristics on which many studies for its applications are focused throughout the many fields. The paper is on the measurement of the strain caused by the characteristics and the temperature changes of the GTA welded zone employed with 3D ESPI system that is functionally modified through the laser ESPI system. This system may be applied the steel plate such as for the electronics, chemistry, flood instrument and electronic appliances.

• 대한치과의사협회지
• /
• 제22권12호통권187호
• /
• pp.1075-1082
• /
• 1984

교근에 대한 휴지기 측정은 치과질환의 하나인 TMJ증후군의 진단에 매우 유용한 방법이다. 본 연구에서는 마이크로 프로세서를 이용하여 휴지기를 측정함에 있어서 환자의 근신호에 따른 이득조정이 필요없고 실행시간도 빠르며 가격이 저렴하고 사용이 매우 편리한 치과용 의료장비를 설계하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
• /
• pp.232-235
• /
• 2000

Design and experiments of a nondestructive system to inspect deterioration of ACSR-OC (ACSR Outdoor Cross-linked Polyethylene Insulated Wire usually used in HV overhead distribution lines presented in this paper. ACSR-OC conductor built to pollutants air for a long period would be easily progress to corrode so that it may lead to the reduction of the effective cross section area of conductors. A fault diagnosis system consisting of a solenoid sensor, a constant current source with RF frequency signal processing unit and a motor driver/controller designed and implemented. This instrument can dot the sensor output variation due to deterioration corrosion, continuously. As a result, it was shown such corrosion detector can readily be utilized estimating the diameter change due to deterioration overhead distribution lines and in giving an warning or inform before severe aged conductor lead to fail.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 하계학술대회 논문집
• /
• pp.290-290
• /
• 2010

For real-time recognition of accurate measuring instrument, the adaptive parameter typed Circular Nural-Net Recognition is proposed. The fast nural network system acted by a replacement of the conventional nural network has good real-time convergence. we are applied proposed nural network to utilize various control and investigation equipments.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 A
• /
• pp.245-247
• /
• 1992

We utilize as a processor TMS320C25 (Texas Instrument) in making a driver for a 4 pole PM synchronous servo motor. TMS320C25 has a 32bit ALU and a 16 bit hardware multiplier, and the maximum instruction execution rate is 10MIPS at 40MHz. We adopted a space vector modulation PWM method. An interesting point of this work is that PWM wave is generated by utilizing timer interrupts. Hence, in the rest of time the processor can take care of the other routine such as Park's coordinate transformation and the computation required in the feedback loops. Thus, it mates the hardware circuit very simple. Due to the decrease in the number of components, the motor drive system becomes more fault-tolerant and cost-optimized. Also, more flexibility is gained in changing the control parameters.

• 한국전기전자재료학회논문지
• /
• 제25권6호
• /
• pp.462-466
• /
• 2012

In this paper, heat-releasing composite sheets made of AlN, graphite, Al powder and acryl binder as thermoset were prepared using tape casting method. The crystal structure, morphology, thermal conductivity of heat-releasing composite sheet were measured by using X-ray diffractometer, field emission-scanning electron microscopy and laser flash instrument. It was found thermal conductivity of sheet was decided by solid content, composition including AlN, graphite, Al in heat-releasing composite sheets. As a result, 4.56 W/mK of thermal conductivity could be obtained by using LFA 447.

• 한국전기전자재료학회논문지
• /
• 제25권6호
• /
• pp.431-434
• /
• 2012

In this paper, heat-releasing sheets made of AlN powder and acryl binder as thermoset were prepared using tape casting method. The crystal structure and morphology, the thermal properties as nonvolatile solid content and thermal conductivity, and the surface resistance of heat-releasing sheet were measured by using X-ray diffractometer, field emission-scanning electron microscopy, thermo gravimetric analyzer and laser flash instrument, and surface resistance meter. It was proved that thermal conductivity is greatly affected by the content of binder in heat-releasing sheet. Superior thermal conductivity above 3.5 W/mK and suface resistance were obtained at heat-releasing sheet with above 90% of AlN powder.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
• /
• pp.609-612
• /
• 2001

Rogowski coil is made having no ferromagnetic material in a core. So the coil cannot be driven into saturation. This result in that Rogowski coils may be calibrated at relatively low currents. and used with confidence at very high currents. However the lowest level of current that can be measured is limited by the sensitivity of the voltage measuring instrument and system noise. Therefore. geometrical effects were investigated in order to measure high sensitivity of low level current and the significant source of error was examined as well. In the results, the source of error was associated with coil designs. i.e. shape and uniformity of coil and a geometrical location of current source inside and outside of the Rogowski coil.

• Transactions on Electrical and Electronic Materials
• /
• 제8권6호
• /
• pp.289-292
• /
• 2007

Polymethly methacrylate(PMMA) and polydimethlysiloxane(PDMS) surfaces were treated to improve adhesiveness by irradiation of a Nd:YAG pulse laser beam($\lambda=266nm$). A pulse laser beam was directed on a polymer surface in air, and the number of pulses was controlled by mobile velocity of a motorized stage. The laser treated surfaces were investigated using an optical microscope and a contact angle measuring instrument. It was thereby revealed that the contact angles were decreased in the laser treated surface. This in turn led to an increase of oxygen content and improved adhesiveness on the modified surface. With improved surface adhesion, a fluid channel could be formed on the laser treated surface region.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.1007-1008
• /
• 2006

This paper presents a optimal path search of mobile robot using energy efficiency. Proposed method has two goals that determining the velocity of mobile robot and finding the optimal path. We model the relationship of motors' speed and power consumption with quadratic polynomials. In order to verify the effectiveness of the proposed method, we performed simulations on the energy consumption of different paths.