• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.7
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• pp.1285-1289
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• 2008

In this paper, we design COMS system bus that the 1553 Data Bus is able to link all the units of the satellite managed by the SCU using one Prime Data Bus and on Redundant Data Bus. Also we analyze MIL-STD-1553B bus load and relevant exchange memory budgets in system bus of the COMS satellite. This data is used in the satellite mission and software design by system engineer.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.56-60
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• 2005

It is necessary to irrigate for agriculture in Korea and agricultural canals play important roles in irrigation. Nowadays gauging water discharge in canals is important because of water shortage in Korea. But It is rare to gauging water discharge in canals. Several water level gauges are installed in agricultural canals through TM/TC. But the abilities of the gauges are insufficient for agricultural water metering. In this situation, we are developing the water discharge metering system which is inexpensive and easy to maintain.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.1
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• pp.80-90
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• 2014

The objective of this research is to estimate the stand volume of Pinus koraiensis, by using the investigated volume and the information of remote sensing(RS), in the research forest of Kangwon National University. The average volume of the research forest per hectare was $307.7m^3/ha$ and standard deviation was $168.4m^3/ha$. Before and after carrying out 3 by 3 majority filtering on TM image, eleven indices were extracted each time. Independent variables needed for linear regression equation were selected using mean pixel values by indices. The number of indices were eleven: six Bands(except for thermal Band), NDVI, Band Ratio(BR1:Band4/Band3, BR2:Band5/Band4, BR3:Band7/Band4), Tasseled Cap-Greeness. As a result, NDVI and TC G were chosen as the most suitable indices for regression before and after filtering, and R-squared was high: 0.736 before filtering, 0.753 after filtering. As a result of error verification for an exact comparison, RMSE before and after filtering was about $69.1m^3/ha$, $67.5m^3/ha$, respectively, and bias was $-12.8m^3/ha$, $9.7m^3/ha$, respectively. Therefore, the regression conducted with filtering was selected as an appropriate model because of low RMSE and bias. The estimated stand volume applying the regression was $160,758m^3$, and the average volume was $314m^3/ha$. This estimation was 1.2 times higher than the actual stand volume of Pinus koraiensis.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.4
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• pp.173-179
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• 2002

This paper describes an equalizer using the DFE (Decision Feedback Equalizer) structure, CMA (Constant Modulus Algorithm) and LMS (Least Mean Square) algorithms. The DFE structure has better channel adaptive performance and lower BER than the transversal structure. The proposed equalizer can be used for 16/64 QAM modems. We employ high speed multipliers, square logics and many CSAs (Carry Save Adder) for high speed operations. We have developed floating-point models and fixed-point models using the COSSAP$\^$TM/ CAD tool and developed VHDL filter. The proposed equalizer shows low BER in multipath fading channel. We have performed models. From the simulation results, we employ a 12 tap feedback filter and a 8 tap feedforward logic synthesis using the SYNOPSYS$\^$TM/ CAD tool and the SAMSUNG 0.5$\mu\textrm{m}$ standard cell library (STD80) and verified function and timing simulations. The total number of gates is about 130,000.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.344-344
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• 2020

기후변화 가속화와 국민의 높아진 서비스 요구 수준에 따라 농업용수의 관리방식을 현장인력의 경험적 물관리 방식에서 계측정보 기반의 과락적 물관리 방식으로 전환의 필요성이 대두되어, 2001년부터 농업기반시설 내 무인계측, 원격제어 기능이 탑재된 물관리자동화 시스템을 보급하는 농업용수관리자동화사업을 시행하였다. 농업용수관리자동화사업은 사업시행 초기 연구 결과, 농업기반시설 무인계측 및 원격제어 시스템 보급으로 인력에 의한 관행적 물관리 대비 수리시설의 관리 효율성이 크게 향상되어 유지관리 인력의 절감 및 용수수급의 적정성이 개선될 것으로 분석되었다. 하지만 영농환경의 변화에 따라, 당초 분석결과와 달리 자동화사업 추진과 한국농어촌공사의 유지관리 인력 규모 간 뚜렷한 상관성이 보이지 않는다는 정책기관의 지적이 발생하고 있다. 현재 4차산업기술이 산업 전 분야에 걸쳐 일어나고 있으며 농업분야에도 ICT, LOT, 빅데이터 기술이 도입되어 새로운 가치를 창출하고 있다. 농업용수관리 분야에 있어서는 데이터를 활요한 수요자 중심의 지능형 물관리 사업이 추진되고 있으며, 일정규모 이상 저수지 및 양수장 농업용수 공급량 측정 계측기의 설치가 추진중에 있다. 그러나 현재까지 이러한 설치된 계측장치들의 활용방안에 대해서는 뚜렷한 결과가 도축된 바 없으며, 현재 많은 예산과 인력이 투입되어 설치·운영되고 있는 계측장치들의 활용 방안에 대해서 연구가 필요한 실정이다. 2018년 2,228개 농업기반시설물에 자동화시스템을 설치 완료 하였으나, 각종 장비의 비표준화, 효과대비 고비용, 잦은 통신두절 등의 기술적 문제로 인해 현업부서의 수자원관리 업무에서 자동화시스템의 활용성이 저조한 것으로 관측됐다. 본연구에서는 국내 수자원 계측제어 기술 동향 및 운영환경 조사 결과를 기초로, 기술적 측면의 농업용수관리자동화사업의 개선사항과 4차 산업기술의 농업용수관리자동화사업의 적용방안을 제시 하여 농업용수관리자동화사업 중장기 계획 개정등 향후 정챡수립시 참고 자료로의 활용과 농업용수 효율적 활용과 관리를 위한 TM/TC 미래추진 방안을 제시로 정확하고 신뢰도 높은 농업용수 관리 체계를 구축 하고자 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.205-216
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• 2023

This study aimed to compare the color stability and surface roughness of three-dimensional (3D) printing resin according to polishing methods. 3D-printed resin specimens were fabricated at TC-80DP (Graphy, Seoul, Korea) with a stereolithography 3D printer, and the specimens were divided into three groups, each of which was not polished, was polished using Enhance^®, and was polished using a Sof-Lex^TM disc. The CIE L^*a^*b^* value and the surface roughness of each group were measured and immersed in artificial saliva and orange juice after 0, 1, 7, 30, and 60 days, and the color difference (ΔE^*) was calculated. As a result of the study, no noticeable color change was observed in artificial saliva, but a noticeable color change was demonstrated in orange juice after 60 days of immersion, and the difference was significant. In the Sof-Lex^TM group, surface roughness according to the solution was found to be significantly higher in the orange juice than that in artificial saliva. No significant difference in color change was found according to the polishing method, but surface roughness was significantly lower in the Sof-Lex^TM group than both that of the unpolished group and that of the Enhance^® group. Nevertheless, all groups exhibited clinically acceptable properties regardless of their higher surface roughness than the threshold for plaque accumulation. Overall, this study recommends utilizing Sof-Lex^TM for polishing 3D printing resin when used in primary anterior tooth coverage.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.150-158
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• 2003

In the beam pattern synthesis problem using line source, the relationship between source distribution function and beam pattern may be represented by Fourier transform pair. In this paper, a general method to synthesize the line source distribution for a desired lobe-like beam pattern is presented by developing the nonlinear inversion method based on an iterative sampling technique. This method can be applied to the synthesis of continuously distributed dielectric constants satisfying the desired inverse scattering coefficient patterns when illuminating by TE-polarized and TM-polarized plane waves to arbitrary dielectric material. Furthermore this method can also be applied to the synthesis of transmission line with arbitrary reflection coefficient patterns. Some bandstop spatial filter and dispersive transmission line filter are illustrated for generality.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.65-71
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• 2011

Purpose: The recently adopted multiple confocal SPECT SYSTEM (hereinafter called IQ SPECT$^{TM}$) has a high difference from the conventional myocardial perfusion SPECT in the collimator form, image capture method, and image reconstruction method. This study was conducted to compare this novice equipment with the conventional one to design a protocol meeting the IQ SPECT, and also determine the characteristics and usefulness of IQ SPECT. Materials and Methods: 1. For the objects of LEHR (Low energy high resolution) collimator and Multiple confocal collimator, $^{99m}Tc$ 37MBq was put in the acrylic dish then each sensitivity ($cpm/{\mu}Ci$) was measured at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. 2. Based on the sensitivity measure results, IQ SPECT Protocol was designed according to the conventional general myocardial SPECT, then respectively 278 kBq/mL, 7.4 kBq/mL, and 48 kBq/mL of $^{99m}Tc$ were injected into the myocardial and soft tissues and liver site by using the anthropomorphic torso phantom then the myocardial perfusion SPECT was run. 3. For the comparison of FWHMs (Full Width at Half Maximum) resulted from the image reconstruction of LEHR collimator, the FWHMs (mm) were measured with only algorithms changed, in the case of the FBP (Filtered Back projection) method- a reconstruction method of conventional myocardial perfusion SPECT, and the 3D OSEM (Ordered subsets expectation maximization) method of IQ SPECT, by using $^{99m}Tc$ Line source. Results: 1. The values of IQ SPECT collimator sensitivity ($cpm/{\mu}Ci$) were 302, 382, 655, 816, 1178, and those of LEHR collimator were measured as 204, 204, 202, 201, 198, both at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. It was found the difference of sensitivity increases up to 4 times at the distance of 30 cm in the cases of IQ SPECT and LEHR. 2. The myocardial perfusion SPECT Protocol was designed according to the geometric characteristics of IQ SPECT based on the sensitivity results, then the phantom test for the aforesaid protocol was conducted. As a result, it was found the examination time can be reduced 1/4 compared to the past. 3. In the comparison of FWHMs according to the reconstructed algorithm in the FBP method and 3D OSEM method followed after the SEPCT test using a LEHR collimator, the result was obtained that FWHM rose around twice in the 3D OSEM method. Conclusion : The IQ SPECT uses the Multiple confocal collimator for the myocardial perfusion SPECT to enhance the sensitivity and also reduces examination time and contributes to improvement of visual screen quality through the myocardial-specific geometric image capture method and image reconstruction method. Due to such benefits, it is expected patients will receive more comfortable and more accurate examinations and it is considered a further study is required using additional clinical materials.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.491-494
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• 2009

This paper introduces the design concepts and characteristics of WinDS3000$^{TM}$ which is a trade mark of Doosan's 3MW offshore/onshore wind turbine. WinDS3000$^{TM}$ has been designed in consideration of high RAMS (Reliability, Availability, Maintainability and Serviceability) and cost effectiveness for the TC Ia condition in GL guideline. An integrated drive train design with an innovative three-stage gearbox has been introduced to minimize nacelle weight of the wind turbine and to enhance a high reliability for transmission. A permanent magnet generator with full converter system has been introduced to get higher efficiency in part load operation, and grid friendliness use of 50 Hz and 60 Hz grid. A pitch regulated variable speed power control with individual pitch system has been introduced to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. An individual pitch control system has been introduced to reduce fatigue loads of blade and system. The wind turbine has been also equipped with condition monitoring and diagnostic systems in order to meet maintainability requirements. And internal maintenance crane in nacelle has been developed. As a result, the maintenance cost was dramatically reduced and maintenance convenience also enhanced in offshore condition.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.2 s.332
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• pp.9-16
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• 2005

The performance of satellite range measurement using tone method was analyzed in the presence of satellite link AWGN. The phase errors in range measurement are generated by AWGN of satellite up- and down-link and the degradations of satellite range measurement are dependent on the transmission mode and loop bandwidth of satellite measurement system. The analyzed effects for satellite measurement in presence of satellite link noise were also analyzed with the measured satellite range data via satellite range measurement system operating in satellite link AWGN. In RAU mode, the satellite range differences of 14.4 to 40.6 m were occurred according to the loop bandwidth of satellite range measurement system and the degradation of 0.3 dB compared with theoretical value was generated under condition of the signal-to-noise ratio of 43 dB. In RAU and TM mode, the performances of range measurement were approximately agreed to the that of RAU mode. In order to get the equal performance characteristics with RAU mode, the signal-to-noise ratio of satellite link for RAU and TM mode should be increased by signal power of 2.3 dB, which is a power loss due to transmission of telemetry signal.