• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.44-52
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• 2017

This paper describes a 100 kW high-efficiency isolated DC-DC converter for DC distribution system. The DC-DC converter consists of two dual-active-bridge (DAB) converters in parallel. The operating principle of the DAB converter is explained, and the algorithm for parallel operation of the DAB converters is proposed. Simulation and experiments are conducted to verify the performance of the proposed system. Experimental results demonstrate that the developed converter excellently marks 97.4 percent of peak efficiency under its normal operating condition.

• Knowledge Management Research
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• v.4 no.2
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• pp.79-94
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• 2003

This paper explores the features, patterns and strategies of innovation in knowledge intensive service (KIS) suppliers in Korea. It was found that characteristics of service innovation and manufacturing innovation tend to converge. Also, diverging elements were found particularly in organizational dimension in the innovation of the service sector. Investigation into the case of information and communication technology (ICT) services revealed that KIS suppliers are active in innovation. They obtained ideas required for their innovations from their knowledge activities inside firms and in the process of interaction with user firms. Large KIS suppliers are to a great extent interested in R&D for innovation, while small and medium suppliers are interested in developmental work. Weak knowledge flow was found between KIS suppliers and the public sector like universities and public research institutes.

• Textile Coloration and Finishing
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• v.26 no.1
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• pp.1-6
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• 2014

We have designed and synthesized the colorimetric chemosensor through the reactions of 1,2-anthraquinone and indol-3-carboxaldehyde. Due to its well conjugated D-${\pi}$-A system and the existence of NH-fragment in indole moiety, we expected that the chemosensor can detect target anions with NH-fragment in indole part of the structure. In this regard, UV-Vis absorption spectra were measured to investigate sensing properties of the probe toward different anions in DMSO. This chemosensor shows to detect fluoride anions with absorption change in intensity. These properties are mainly related to the deprotonation effect. ICT system in this molecule was also observed by the computational approach using Material Studio 4.3 package.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.97-99
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• 2014

포항가속기 연구소에서 4세대 전자를 가속시키기 위하여 RF 공급원으로 사용하는 펄스 모듈레이터의 고전압 안정도는 50ppm 이하의 고전압이 요구된다. 200 MW 모듈레이터에 공급하기 위하여 개발된 고전압 CCPS사양은 50 kV, 120 kJ/sec, 2400mA, 20ppm이하이다. XFEL용 모듈레이터는 고정밀 고전압 CCPS를 적용하여 운전하였으며 모듈레이터 사양은 400kV, 500A, 8us, 60Hz, beam voltage stability 0.005(%)이다. 본 논문에서는 개발한 고정밀 고전압 CCPS를 사용하여 시험한 모듈레이터의 시험 결과에 대하여 발표하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.203-209
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• 2019

In this work, a new land-specific resistance measuring device (GM) and a measuring probe (Grounding Rod) are connected to the WENNER quadrant as power-line communication (PLC). In groups of two (P1,P2) probes, five to ten probes are installed in series on the ground at intervals of 1m, 2m, 4m, 8m, and 16m, respectively. If the PLC signal from the GMD is detected by the receiver of the Probe 1 (P1) for measurement, the minute voltage and current for measurement flow from the PSD (power supply) attached to the probe to the ground, and then, through the soil between P1 and P2, enters the Probe 1 (P2). The resistance value is then measured by the principle of voltage drop due to ground resistance. Measure the earth resistance every T seconds up to 1 trillion and store the measured data on the Arduino Server mounted on the main equipment. Stored measurement data can be derived from formulas by Ohm's Law and from inherent resistance (here,). Data obtained in real time will be linked to CDGES programs installed on Main PC, enabling data analysis and real-time monitoring of the ground environment on land. In addition, a three-dimensional display is possible with 3D graph support by identifying seasonal characteristics such as temperature and humidity of land (soils). The limitations of the study will require specific application measures of Test Bed for commercial access to a model that has been developed and operated experimentally.

• Proceedings of The KACE
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• 2017.08a
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• pp.31-34
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• 2017

현재 4차 산업혁명이 사회에 던지는 화두는 다양하다. 첫째, 소프트웨어 중심 사회이다. 빅 데이터, 인공지능 기술 등이 다양한 분야와 결합하고 그 중심에는 소프트웨어가 있다. 앞으로 소프트웨어 교육이 필수적이고 강화되어야 할 이유다. 둘째, 생산과 소비가 결합된다는 것이다. 즉, 더 이상 소비자가 수동적인 소비자로만 남지 않으며, 획일화된 제품과 서비스에 흥미를 느끼지 않고, 소비자가 직접 자신이 구매할 제품 생산과 판매에 관여하는 '프로슈머(prosumer)' 필요한 물건을 직접 만드는 D.I.Y.(Do It Yourself), 3D 프린팅 등이 새로운 소비 방식을 대표한다[3]. 이에 메이커 운동이 떠오르고 있고, 메이커에 대한 관심이 커지고 있다. 우리나라는 2015 개정 교육과정을 통해 소프트웨어 교육을 강화했다. 초등학교에서는 5~6학년 실과 교과의 정보 관련 단원이 ICT활용 중심에서 소프트웨어 기초 소양 내용 중심으로 개편되었다[1]. 아직 교육과정이 시행되기 전이지만 선도학교나 연구학교를 통해 진행된 소프트웨어 교육을 보면 기능을 익히는 프로그래밍 교육이 주류를 이루고 있고, 이래서는 다양하고 창의적인 결과물을 도출할 수 없다. 이를 해결하기 위해서는 디자인 사고를 도입할 수 있다. 디자인 사고는 인간을 관찰하고 공감하여 소비자를 이해한 뒤, 다양한 대안을 찾는 확산적 사고와 주어진 상황에 최선의 방법을 찾는 수렴적 사고의 반복을 통하여 혁신적 결과물을 도출하는 창의적 문제 해결 방법 중 하나이다[5]. 따라서 본 연구에서는 초등학생들의 소프트웨어 교육을 위한 디자인 사고 기반 메이커 교육 프로그램을 개발하고자 한다.

• Biomedical Engineering Letters
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• v.8 no.4
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• pp.383-392
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• 2018

For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.5
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• pp.237-242
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• 2023

Research on high-performance walking robots is being actively conducted, and quadruped walking robots are receiving a lot of attention due to their excellent mobility and adaptability on uneven terrain, but they are difficult to introduce and utilize due to high cost. In this paper, to increase utilization by applying intelligent functions to a low-cost quadruped robot, we present a method of improving uneven terrain overcoming ability by mounting IMU and reinforcement learning on embedded board and automatically detecting objects using camera and deep learning. The robot consists of the legs of a quadruped mammal, and each leg has three degrees of freedom. We train complex terrain in simulation environments with designed 3D model and apply it to real robot. Through the application of this research method, it was confirmed that there was no significant difference in walking ability between flat and non-flat terrain, and the behavior of performing person detection in real time under limited experimental conditions was confirmed.

• Convergence Security Journal
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• v.21 no.4
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• pp.31-39
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• 2021

In the R&D of the Defense Weapon System, the evaluation of technical and operational aspects has been developed with the military's own test evaluation system, and organizations and procedures have been established and implemented. However, with the recent advancement of information and communication technology in the private sector, it is often necessary to test-apply it to the field by enhancing the operability and suitability of technologies required for defense before development is complete. This paper investigates and analyzes the process for conducing empirical tests on the latest AI vaccine system R&D prototype organized by the Ministry of Science and ICT which proposes an improved demonstration plan for the existing military information system test evaluation procedure. In addition, under the specificity and security of the defense environment, we would like to present a practical demonstration plan and the improvement of the process for demonstrating the security technology prototype.

• Informatization Policy
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• v.17 no.4
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• pp.3-22
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• 2010

The purpose of this study is to provide the fruitful directions for the future studies on smart work by analyzing the past and present trends that are related to smart work. For this, a wide range of materials and MA and PhD treatises produced from 1992 to the present have been collected and have been analyzed on the basis of various standards, including objective of study, approach method, methodology, method of data collection, statistical technique of analysis, summary of problems and alternativesto overcome limitations. Lessons and implications of this study for the possibility of smart work are presented. I hope this study will contributeto future studies concerned about smart work.