• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.214-219
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• 2012

초음파전파영상화(UPI) 시스템은 2007년에 첫 논문 발표를 통해 시스템 개발이 보고된 이후 소프트웨어 및 하드웨어적 측면에서 다양한 형태로 발전된 시스템의 개발이 이루어졌다. 본 기고에서는 기본 UPI 시스템, 섬유파트랜스듀서 UPI 시스템, 순수광학시스템으로서 광섬유 센서 UPI 시스템, 완전비접촉 시스템으로서의 공기정압압전센서 UPI 시스템 및 레이저도플러진동계 UPI 시스템, 장거리 UPI 시스템, 옥외 적용성에 필수적인 저온환경 UPI 시스템 등을 소개한다.

• Smart Structures and Systems
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• v.29 no.2
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• pp.301-309
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• 2022

Protective coatings are most widely used anticorrosive structures for steel structures. The corrosion under the coating damages the host material, but this damage is completely hidden. Therefore, a field-applicable under-coating-corrosion visualization method has been desired for a long time. Laser ultrasonic technology has been studied in various fields as an in situ nondestructive inspection method. In this study, a comparative analysis was carried out between a guided-wave ultrasonic propagation imager (UPI) and pulse-echo UPI, which have the potential to be used in the field of under-coating-corrosion management. Both guided-wave UPI and pulse-echo UPI were able to successfully visualize the corrosion. Regarding the field application, the guided-wave UPI performing Q-switch laser scanning and piezoelectric sensing by magnetic attachment exhibited advantages owing to the larger distance and incident angle in the laser measurement than those of the pulse-echo UPI. Regarding the corrosion visualization methods, the combination of adjacent wave subtraction and variable time window amplitude mapping (VTWAM) provided acceptable results for the guided-wave UPI, while VTWAM was sufficient for the pule-echo UPI. In addition, the capability of multiple sensing in a single channel of the guided-wave UPI could improve the field applicability as well as the relatively smaller size of the system. Thus, we propose a guided-wave UPI as a tool for under-coating-corrosion management.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.9
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• pp.191-203
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• 2022

The ecosystem for digital payments in India has expanded quickly during the last decade. A synthesis of technical advancements and progressive governmental laws and regulations has fuelled this expansion. Particularly, the UPI system has assisted India in transitioning from a nation heavily reliant on cash for daily transactions to one with fewer cash transactions. The study attempted to determine how Financial Inclusion (FI) through a socio-techno-ecosystem impacts digital payment systems. FI involves ensuring financial services, products, and an adequate amount of credit without discrimination against the weaker section of society. The study has established that FI impacts the UPI. The finance infrastructure thus helps to develop an ecosystem where financial access and the awareness level help people to transit to new channels of payment. We have used secondary data of 27 banks for sixteen quarters and four years, i.e., for the financial years 2016-17 to 2019-20. It is observed from the current study that the offsite_ATM plays a significant role in the value creation of the UPI. Our study implies that it will help retailers, individuals, and business houses to use UPI platforms for swift payments without hassle. Also helpful for industries that are still not digitally disrupted and industry-specific UPI transactions.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.467-475
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• 2016

Ultrasonic propagation imaging (UPI) has shown great potential for detection of impairments in complex structures and can be used in wide range of non-destructive evaluation and structural health monitoring applications. The software implementation of such algorithms showed a tendency in time-consumption with increment in scan area because the processor shares its resources with a number of programs running at the same time. This issue was addressed by using field programmable gate arrays (FPGA) that is a dedicated processing solution and used for high speed signal processing algorithms. For this purpose, we need an independent and flexible block of logic which can be used with continuously evolvable hardware based on FPGA. In this paper, we developed an FPGA-based ultrasonic propagation imaging system, where FPGA functions for both data acquisition system and real-time ultrasonic signal processing. The developed UPI system using FPGA board provides better cost-effectiveness and resolution than digitizers, and much faster signal processing time than CPU which was tested using basic ultrasonic propagation algorithms such as ultrasonic wave propagation imaging and multi-directional adjacent wave subtraction. Finally, a comparison of results for processing time between a CPU-based UPI system and the novel FPGA-based system were presented to justify the objective of this research.

• Journal of Korean Society of Rural Planning
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• v.17 no.1
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• pp.13-27
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• 2011

This study analyzed the budget investment plans for the unit-project items(UPI) of 176 project districts for the rural village comprehensive development projects (RVCDP). This study classified the master plan reports of 176 project districts into 88 unit project items in aspect of project management, in order to analyze characteristics of distribution of budget in each project item. Most of all unit project items have similar types of uniform distribution with plus skewness in frequency pattern analysis except the total budget of the project district. This study analyzed the characteristics of budget distribution per province, year, and geographical types of region. Furthermore this paper also analyzed ratio of budget in unit project items to find out distribution pattern of each budget between project items over time. The hierarchical system for UPI of RVCDP consisted of three steps, which are 4 items of the first step on Strength of Rural-urban Exchange & Regional Capability (RURC), Green-income Infrastructure & Facility (GIF), Culture- health-welfare Facility, and Eco-environment & Landscape facility (ELF), 13 items for the second one, and 52 items for the third project items. From the results of the budget investment analysis for 5 years from 2004 to 2008, the budget investment ratios of RURC and ELF have steady state for every year, while GIF in decreasing and ELF in increasing over time. The ratios of UPI on infrastructure were decreased, whereas those on culture, health, and welfare were increased. Portion of tow project items among 52 items, which are community centers for village residents and rural experimental study facility, has 30% of total budget investment. Futhermore, the budget ratios of seven project items showed 50% of total budget. Average value of project budgets for five years was optimized as a type of exponential function in the case of decent array for ranking order.

• Smart Structures and Systems
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• v.22 no.2
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• pp.223-230
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• 2018

This study examines a non-contact laser scanning-based ultrasound system, called an angular scan pulse-echo ultrasonic propagation imager (A-PE-UPI), that uses coincided laser beams for ultrasonic sensing and generation. A laser Doppler vibrometer is used for sensing, while a diode pumped solid state (DPSS) Q-switched laser is used for generation of thermoelastic waves. A high-speed raster scanning of up to 10-kHz is achieved using a galvano-motorized mirror scanner that allows for coincided sensing and for the generation beam to perform two-dimensional scanning without causing any harm to the surface under inspection. This process allows for the visualization of longitudinal wave propagation through-the-thickness. A pulse-echo ultrasonic wave propagation imaging algorithm (PE-UWPI) is used for on-the-fly damage visualization of the structure. The presented system is very effective for high-speed, localized, non-contact, and non-destructive inspection of aerospace structures. The system is tested on an aluminum honeycomb sandwich with disbonds and a carbon fiber-reinforced plastic (CFRP) honeycomb sandwich with a layer overlap. Inspection is performed at a 10-kHz scanning speed that takes 16 seconds to scan a $100{\times}100mm^2$ area with a scan interval of 0.25 mm. Finally, a comparison is presented between angular-scanning and a linear-scanning-based pulse-echo UPI system. The results show that the proposed system can successfully visualize defects in the inspected specimens.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.411-416
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• 1996

최근 웨스팅하우스사가 SECY-83-472에 근거하여 개발한 최적평가방법론인 WCOBRA/TRAC UPI EM을 이용하여 Appendix K, Superbounded, Nominal 계산을 고리 1호기에 대하여 수행하였다. 15%증기발생기 관막음율, 출력 첨두 계수 2.35, 최대 선형 열출력 15.588kw/ft을 사용하여 계산한 결과 Appendix K 최대 피복재 온도는 1941℉로서 KAERI/Siemens가 RTSR 작성시 수행한 해석에 비하여 운전여유도가 증가한 것으로 나타났으며, 그 결과가 SECY 방법론에 합당함을 확인하였다.

• Composites Research
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• v.29 no.5
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• pp.288-292
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• 2016

In this paper, a novel ultrasonic propagation imaging system, called a full-field pulse-echo ultrasonic propagation imaging (FF PE UPI) system is introduced. The system nondestructively inspected targets with two-axis translation stage. The coincident laser beams for ultrasonic sensing and generation are scanned and pulse-echo mode laser ultrasounds are captured. This procedure makes it possible to generate full-field ultrasound in through-the-thickness direction as large as the scan area. Structural inspection results in the form of full-field ultrasonic wave propagation videos are introduced, which are painted sandwich control surfaces. In addition, the inspection results of FF PE UPI system are compared with conventional ultrasonic testing methods such as waterjet and portable C-scan.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.329-332
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• 1991

In this studies, variation of the sintering temperature with a single round type piezoelectric actuator of PZT 401 powder [UPI CO.] were fabricated. The piezoelectric properties were investigated as specimens with sintering temperature $1000^{\circ}C,\;1100^{\circ}C,\;1200^{\circ}C,\;1270^{\circ}C,\;1300^{\circ}C$. The strain was measured with respect to the variation of the electric field(500V-1000V), time, temperature($18^{\circ}C-40^{\circ}C$) and humidity(35%-93%).

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.158-162
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• 2006

급격한 도시화로 인하여 도시기반시설의 필요성에 의해 도시계획시설들이 많이 결정되었다. 헌법재판소는 도시계획시설의 지정으로 인한, 토지소유자의 토지 사적 이용권의 배제에 대해 헌법 불합치 판정을 내렸고, 2000년 1월 28일 도시계획법의 개정이 이루어짐으로써, 기존의 미집행 시설로 인한 사유권의 침해는 시급하게 해결되어야 할 과제로 발전하게 되었다. 이에 따라 장기미집행 도시계획시설에 대한 전면적인 재검토 및 재정비 계획을 수립하게 되었다. 이를 위해 본 연구에서는 GIS 분석기법을 이용하여 미집행 도시계획시설의 데이터베이스를 구축하였으며, 향후 LMIS의 지리정보 전산화일과, UPIS의 도시계획시설 데이터, 조서 자료 및 고시자료 등을 이용하여 미집행 도시계획시설 관리를 위한 기본 DB를 구축하고자 한다.