• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.4
• /
• pp.94-101
• /
• 2011

Various kinds of medical imaging devices have been studied to develop periapical radiography. However, there are some problems such as high x-ray exposure rate and pains for patients because of the problems caused by intra-oral sensor based radiography system. In this study, a new concept of periapical radiography, intra oral X-ray tube and detector system, is introduced to solve these problems. This system is made up of miniature X-ray tube based on subminiature thermal electron or cold electron, CMOS based detector, and a body including automatic position and system control devices. In order to confirm the possibility of proposed new concept to periapical radiography, miniature x-ray tube from XOFT corporation is used to develop new x-ray system, and the performance evaluation of this system is performed according to collimator. Also, dental images are compared after acquiring both images from existing system versus new concept of system. As a result, new concept of system showed excellent image. Thus, it is considered that new concept of system will have a significant effect on medical imaging technology.

• Information and Communications Magazine
• /
• v.27 no.9
• /
• pp.30-38
• /
• 2010

본 논문은 인간의 청각기능을 보조하거나 대체할 수 있는 차세대 청각보조장치 및 완전 이식형 인공와우에 관련한 기술동향에 대해서 기술한다. 청각보조장치는 MEMS 마이크로폰과 음장가시화 기술을 기반으로 하여 청각정보를 시각적으로 전달하고자 하는 장치이다. 이를 위해서는 초소형 MEMS 마이크로폰의 최적화 및 실시간 음장가시화 기술 개발이 선행되어야 한다. 차세대 생체모사 인공와우 기술은 기존 인공와우의 단점인 잦은 충전, 장애 노출 등을 극복하고 향상된 음감을 전달할 수 있는 완전 이식형 인공와우로서 그 기술동향을 논하고자 한다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.21 no.5
• /
• pp.80-87
• /
• 2017

The performance of a pyrotechnic device that consists of donor/acceptor pair separated by a bulkhead relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor explosives. In this research, a micro Kapton flyer was accelerated by an exploding foil initiator (EFI) to figure out shock sensitivity of hexanitrostilbene (HNS) to impact. The averaged shock pressure and duration imparted to the explosive by flyer impact are measured by using a velocity interferometer for any reflector (VISAR) and impedance matching technique. Consequently, this research shows the possibility to determine the critical flyer velocity for initiating the miniaturized pyrotechnic unit by determining the relations between the impact velocity, the amplitude and width of impact loading.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.4
• /
• pp.26-38
• /
• 2000

전파 방해장치(jammer)의 핵심 부품이라 할 수 있는 광대역 고출력 증폭기는 초소형화, 초고주파화 및 초고출려고하하는 다양성을 각각 다른 형태의 증폭장치에서 실현하고 있다. 이 논문에서는 먼저 진공 고출력 증폭기를 반도체 증폭기와 비교하며 각각의 영향권에서 대해 비교하였다. 본론에서는 첫째로 초소형화되어가는 광대역 TWT와 MMIC와 같은 반도체소자와 연합하여 효율이 높은 초소형 고출력(>100W CW) 증폭기의 혁신을 일으키는 MPM(Microwave Power Module)을 소개하였고 둘째로는 고출력(>kW)으로 초고주파화(밀리미터파) 되어가는 Gyro-TWT를 소개하였다. 세째로 원리적으로는 현재 무기체계의 전면적인 수정을 불가피하게 할지 모르는 초고출력화(>GW) 되어가는 HPM(High Power Microwaves)이 소개되었다. 마지막으로 한국에서의 고출력 증폭기에 관련된 연구개발 상황과 TWT국산화에 대한 현황이 소개되었다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.95-96
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1169-1170
• /
• 2010

• Journal of Welding and Joining
• /
• v.22 no.4
• /
• pp.12-19
• /
• 2004

오늘날 IT산업의 괄목할 만한 성장으로 IT관련 휴대장비의 시장은 폭발적으로 증가하고 있다. 전통 제조업분야에서도 IT산업과 메카트로닉스의 발전 덕택에 경량화, 소형화된 전자소자나 전기소자 및 관련 센서, 액츄에이터를 활용할 수 있데 됨에 따라 기계 장비 및 장치가 점점 더 소형화되고 있다.(중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.10a
• /
• pp.477-478
• /
• 2013

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.4
• /
• pp.371-378
• /
• 2015

Range extenders, which are power generation systems driven by small engines, extend the driving distance and time of electric vehicles (EVs) through continuous charging of batteries. The currently used range extenders with gasoline engines pose limitations with regard to the realization of high-power compact systems, owing to their complex structure and low energy density. In contrast, micro gas turbine (MGT) range extenders (MGT power packs) possess high power and low weight, and can therefore be significantly reduced in size despite increase in speed. In this study, an MGT power pack for the range extenders of EVs was developed using a turbo-prop micro turbine, an alternator for passenger vehicles and electric batteries. The operating characteristics of the MGT power pack were measured through a series of experiments conducted under electrical no-load and load conditions. Their power generation performance and efficiency were measured under various electrical loads and power transmission gear ratios. From the results, electrical load was found to have no influence on power generation performance. The maximum electrical power output was 0.8 kW at a core turbine speed of 150 krpm, and the application of 3:1 reduction gear to the turbine output shaft increased the power to 1.5 kW by 88%. This implies that the test results demonstrated stable power generation performance of the MGT power pack regardless of vehicle load changes, thus revealing its feasibility for use with the range extenders of EVs.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.879-884
• /
• 2007

Flywheel energy storage systems have advantages over other types of energy storage devices in such aspects as unlimited charge/discharge cycles and environmental friendliness. In this paper we propose a millimeter scale flywheel energy storage device. The flywheel is supported by a pair of passive magnetic bearings and rotated by a toroidally wound electric motor/generator. The geometry of the bearings is optimized for the maximum dynamic performance.