• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.14 no.4
• /
• pp.160-166
• /
• 2015

Ultrasonic machining (USM) has been considered a new, cutting-edge technology that presents no heating or electrochemical effects, with low surface damage and small residual stresses on brittle workpieces. However, nowadays, many researchers are paying careful attention to the disadvantages of USM, such as low productivity and tool wear. On the other hand, in this study, a high-performance rotary ultrasonic drilling (RUD) spindle is designed and assembled. In this system, the core technology is the design of an ultrasonic vibration horn for the spindle using finite element analysis (FEA). The maximum spindle speed of RUM is 9,600 rpm, and the highest harmonic displacement is $5.4{\mu}m$ noted at the frequency of 40 kHz. Through various drilling experiments on glass workpieces using a CVD diamond-coated drill, the cutting force and cracking of the hole entrance and exit side in the glass have been greatly reduced by this system.

• Journal of Sensor Science and Technology
• /
• v.12 no.2
• /
• pp.95-101
• /
• 2003

Ultrasonic transmitter used for scale prevention in boiler or heat exchanger is composed of the magnetostrictive material which transforms electric energy into ultrasonic wave and the horn which amplifies generated ultrasonic wave and transfers it into medium loaded. In this paper, we have performed the shape design for magnetostrictive material and analyzed a few type of horns which amplify generated ultrasonic wave and found each solution theoretically. Final length of the horn has been determined by measuring the sound pressure in medium between theoretical value and experience data. At last we have given the results of our study for the effects of ultrasonic wave irradiated by manufactured ultrasonic transmitter on preventing scale deposition on test pipe under the similar condition to boiler.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.10
• /
• pp.935-940
• /
• 2016

Directed energy weapon enables to radiate the concentrated energy so as to result in distraction and overload of the target electronics. Analysis on effectiveness of weapon system can be important consideration in order to determine performance and design weapon system. In this paper, air defense weapon system, which is one of directed energy weapon system is studied. In order to analyze the effectiveness, the reflector antenna with high power circularly polarized horn antenna is designed, and power density in axial effective area is simulated and calculated using Friis formula. Through the study, the validity of antenna system is verified, and the effectiveness of directed energy weapon system on the target is evaluated.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.6
• /
• pp.811-818
• /
• 2013

In this paper, we have designed the elliptical dual offset gregorian antenna which can use Ka band earth station antennas in the fixed-satellite service. The structure of antenna is increasing the antenna gain by decreasing blockage areas and decreasing wind effects by shortening height of the antenna. The corrugate horn antenna for this antenna has symmetric radiation patterns and low side lobe levels that can meet ITU-R envelope. The distribution of electric field on a aperture of main reflector is calculated by an ray-tracing method that use the radiation pattern of the feed horn. The final geometric of antena is decided by choosing the distribution that comply with antenna requirement. The FEKO analysed electrical performance of this antenna. The fabricated antenna has 45.0dBi(@30.0GHz)/41.7dBi(@20.2GHz), high efficiency and low side lobe level that meet ITU-R S. 580-6 envelope.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.164-166
• /
• 2008

Ultrasonic welder joins with a horn and a booster for amplification of the mechanical displacement. This coupling generates other resonance points at a frequency range lower than the piezoelectric material's resonance frequency. Therefore, frequency variation range through PLL control was proposed in order to prevent reaction to these resonance points.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1348-1350
• /
• 1994

In this study, various nozzle of ultrasonic spray were designed by using Langevin type electrostriction transducer. The electrical and dynamic characteristics of ultrasonic nozzle with various horn type were investigated. We obtained the average particle size and size distribution profiles with output frequency.

• Transactions of Materials Processing
• /
• v.22 no.1
• /
• pp.36-41
• /
• 2013

The present study examines the micro-pattern replication on a plastic film using ultrasonic imprinting. Ultrasonic imprinting uses ultrasonic waves to generate repetitive microscale deformation in the polymer film. The resulting deformation heat on the surface of the film causes the surface region to soften sufficiently so that a replication of the micro-pattern can be obtained. To successfully replicate the micro-pattern on a large area of polymer film, a high replication ratio is needed as well as good uniformity over the entire region. In this study, a horn design is investigated by finite element analysis and is optimized through a response surface analysis. In the ultrasonic imprinting experiments, the response surface method was also used to determine the optimal processing conditions for better replication characteristics.

• Transactions of Materials Processing
• /
• v.19 no.6
• /
• pp.363-371
• /
• 2010

In ultrasonic vibration drawing, the drawing forces can be reduced by applying ultrasonically oscillating dies. Ultrasonic vibration drawing has been considered as a means of accommodating high-level drawing processes such as shaped wire, ultrafine wire, and the wire drawing operation in semidry or dry condition. Prior studies were attempted to analyze the mechanism of improved drawing performances, such as reduced drawing force and improved lubrication characteristic. However, researches on design rule for ultrasonic vibration drawing system are not yet carried out. The principal objectives of this work are to design a set of tooling capable to superimpose the oscillations and to observe by experiments the influence of the ultrasonic oscillations on the wire drawing.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.1
• /
• pp.12-17
• /
• 2018

This study describes the design and implementation of Antenna for Digital Satellite Communication. The Antenna unit for SHF band consists of Reflector, Septom Polarizer, Feed Horn and Support Frame etc. Thought analysis of space environment before production, the possibility of the malfunction of equipment minimized and we designed a reliable Antenna through simulation for vibration and thermal analysis generated during the launch, and compared pre-simulation of main performance results to test results about main performances of Antenna after production. After fabricating the antenna, the maximum gain of the antenna main beam is 36.5dBi, which satisfies the requirement of 35dBi or more, and it also satisfies the requirement of -20dB for return loss of less than -24dB. Also, the isolation of the transmission and reception of the antenna is -22.6dB or less, which satisfies the requirement of -20dB or less. The antenna for digital satellite communication described in this paper can be used in the satellite field of geostationary earth orbit and low earth orbit requiring high reliability in the future.

• Journal of the Korean Society of Costume
• /
• v.58 no.4
• /
• pp.35-46
• /
• 2008

The purpose of this study was to closely examine the history of glasses and their cases used in the middle and late of Joseon Dynasty and identify inherent quality of our traditional glasses cases through color analyses of glasses cases' material and shape. While theoretical examination was conducted based on the literatures of glasses and their cases that firstly appeared in around Japanese Invasion (Imjin war) of Korea in 1592, practical analyses were demonstrated on photos of glasses cases used in the middle and late of Joseon Dynasty collected from both museum pieces and the internet which were grouped into wood, fabric, paper, sharkskin, hawksbill and cow's horn in accordance with their materials. 623 color samples were abstracted from collected 159 glasses cases and quantity analyses on each material were performed respectively. Abstracted representative colors based on the result of color analyses were classified into the main materials and accessories' color scheme. The result of this study are as follow: firstly, both Yellow and Yellow Red were mostly used in main materials. In Fabric case's colors were widely used in embroidery and in animal matter material cases such as sharkskin, hawksbill and cow's horn, which can be used as itself or dyed, Green Yellow shown in high frequency. Secondly, accessories were analyzed into similarity coloration with main materials. From this finding, it turns out that our traditional cases have characteristic of similarity coloration between main materials and accessories. Red Purple and Purple Blue in high frequency in accessories used as an accent color. Finally, based on the analysis of hue and tone, while the middle and low value colors shown in very high frequency, the high-chroma colors hardly shown.