• 한국조명전기설비학회지:조명전기설비
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• 제7권2호
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• pp.36-40
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• 1993

본 논문에서는, 고조파 제거를 위해 PWM 기법을 사용할 때 회로의 구성이 복잡해지고, 제어가 어렵다는 단점을 개선하기 위하여 기준 신호와 부하의 기준 모델(Model)에서 유도된 궤환 신호를 폐루프 처리하여 비교함으로써 인버터의 게이팅 신호를 발생하는 MRA(Model Reference Adaptive)PWM 기법을 제시하였고, 제어기의 구성을 마이크로프로세서 및 아나로그 회로로 설계하였다. 일반적인 정현 PWM 기법을 사용했을 경우, PWM기법을 이용하여 전원에 대한 출력 전압의 비가 낮기 때문에 발생되는 전압 이용율 저하를 MRA PWM 기법을 이용하여 보상할 수 있었다. 또한 사다리꼴(Trapezoidal) 신호를 기준 신호로 사용함으로써 선전류의 저차 고조파를 줄일 수 있었으며, 비교적 간단한 수식을 이용하여 실시간 계산(On-line computation)으로 스위칭 패턴을 발생하였다.

• Journal of Positioning, Navigation, and Timing
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• 제12권4호
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• pp.359-367
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• 2023

In order to ensure the high-integrity of reference stations of satellite navigation system, cycle slip should be precisely monitored and compensated. In this paper, we proposed a cycle slip algorithm for the integrity monitoring of the reference stations. Unlike the legacy method using the Melbourne-Wübbena (MW) combination and ionosphere combination, the proposed algorithm is based on ionosphere combination only, which uses high precision carrier phase observations without pseudorange observations. Two independent and complementary ionosphere combinations, Ionospheric Negative (IN) and Ionospheric Positive (IP), were adopted to avoid insensitive cycle slip pairs. In addition, a second-order time difference was applied to the IN and IP combinations to minimize the influence of ionospheric and tropospheric delay even under severe atmosphere conditions. Then, the cycle slip was detected by the thresholds determined based on error propagation rules, and the cycle slip was identified through weighted least square method. The performance of the proposed cycle slip algorithm was validated with the 1 Hz dual-frequency carrier phase data collected under the difference levels of ionospheric activities. For this experiment, 15 insensitive cycle slip pairs were intentionally inserted into the raw carrier phase observations, which is difficult to be detected with the traditional cycle slip approach. The results indicate that the proposed approach can successfully detect and compensate all of the inserted cycle slip pairs regardless of ionospheric activity. As a consequence, the proposed cycle slip algorithm is confirmed to be suitable for the reference station where real time high-integrity monitoring is crucial.

• 대한전자공학회논문지SD
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• 제46권8호
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• pp.79-85
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• 2009

본 논문에서는 온도 및 공정 보상 전류 미러(temperature and process compensation current mirror: TPC-CM)를 이용한 정밀 전류 레퍼런스를 제안하였다. 온도 변화에 영향을 받지 않는 기준 전류는 절대 온도에 비례하여 증가하는 PTAT (proportional to absolute temperature) 전류와 온도에 반비례하여 감소하는 CTAT(complementary to absolute temperature) 전류의 합으로 생성된다. 그러나 온도 계수(temperature coefficient)와 기준 전류의 크기는 공정 변화에 크게 영향을 받는다. 이런 공정 변화를 보정하기 위하여, 제안된 TPC-CM에서는 온도 계수와 기준 전류의 크기를 조절하는 두 개의 이진 가중치 전류 미러(binary weighted current mirror)를 이용하였다. 제작된 각 칩마다 PTAT 전류와 CTAT 전류를 측정한 후, 기준 전류의 크기가 온도에 상관없이 일정하도록, TPC-CM의 스위치 코드를 결정하고 그 값을 비휘발성 메모리에 저장한다. 시뮬레이션에서 TPC-CM는 공정변화 영향을 19.7%에 서 0.52%로 줄였다. 제안된 전류 레퍼런스는 3.3V 0.35um CMOS 공정을 이용하여 제작되었으며, 측정된 칩의 기준 전류 변화율은 $20^{\circ}$C${\sim}$100$^{\circ}$C에서 0.42%였다.

• Journal of Animal Science and Technology
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• 제63권6호
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• pp.1232-1246
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• 2021

Recently, the cattle genome sequence has been completed, followed by developing a commercial single nucleotide polymorphism (SNP) chip panel in the animal genome industry. In order to increase statistical power for detecting quantitative trait locus (QTL), a number of animals should be genotyped. However, a high-density chip for many animals would be increasing the genotyping cost. Therefore, statistical inference of genotype imputation (low-density chip to high-density) will be useful in the animal industry. The purpose of this study is to investigate the effect of the reference population size and marker density on the imputation accuracy and to suggest the appropriate number of reference population sets for the imputation in Hanwoo cattle. A total of 3,821 Hanwoo cattle were divided into reference and validation populations. The reference sets consisted of 50k (38,916) marker data and different population sizes (500, 1,000, 1,500, 2,000, and 3,600). The validation sets consisted of four validation sets (Total 889) and the different marker density (5k [5,000], 10k [10,000], and 15k [15,000]). The accuracy of imputation was calculated by direct comparison of the true genotype and the imputed genotype. In conclusion, when the lowest marker density (5k) was used in the validation set, according to the reference population size, the imputation accuracy was 0.793 to 0.929. On the other hand, when the highest marker density (15k), according to the reference population size, the imputation accuracy was 0.904 to 0.967. Moreover, the reference population size should be more than 1,000 to obtain at least 88% imputation accuracy in Hanwoo cattle.

• 한국정보통신학회논문지
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• 제20권9호
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• pp.1696-1703
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• 2016

본 논문에서는 현재 해양수산부에서 운영 중인 NDGPS 기준국을 SBAS 기준국으로 공동 활용하기 위한 목적으로 사이트 환경 관점에서의 타당성을 확인한다. 이를 위하여 SBAS 기준국의 사이트 환경 요구사항을 도출하고, 본 요구사항을 확인할 수 있는 절차를 수립한다. 그리고 수립된 기준국 사이트 환경 조사 절차를 기반으로 NDGPS 기준국의 현장 조사를 실시하고 그 결과를 분석한다. 이때, 사이트 환경 조사를 위한 사이트 선정은 NDGPS 기준국 17개소를 대상으로 한다. 본 논문의 내용은 NDGPS 기준국을 SBAS 기준국으로 공동 활용하기 위하여 고려해야 할 요소도출 및 위성항법시스템 분야의 기준국 선정 및 구축 시 활용할 수 있다.

• Fisheries and Aquatic Sciences
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• 제19권4호
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• pp.21.1-21.11
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• 2016

Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

• 약학회지
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• 제45권2호
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• pp.227-236
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• 2001

The complexity and variability of both the biologicals and the bioassays used to test them led to the use of the reference standard- a sample of the product of defined purity and potency, against which all preparations of that product must be calibrated. In order to prepare and establish KFDA reference standard for recombinant human growth hormone (somatropin), somatropin substance was filled in ampoules in National Institute for Biological Standards and Control (NIBSC). The candidate KFDA reference standard for somatropin (designated as 98/674) was evaluated to determine the suitability of serving as a KFDA reference standard for somatropin by the collaborative study, in which 10 laboratories participated. Physicochemical analysis and in vivo bioassay were performed by direct comparison with the international somatropin standard 88/624. 98/674 was identified as somatropin by SDS-PAGE, IEF, peptide mapping, and HPLC. Determination of somatropin content by SE-HPLC yielded a mean estimate of 2.01 mg somatropin per ampoule. Data from the study also yielded mean values of 0.39 $\pm$ 0.26% for high molecular weight impurities by SE-HPLC and mean values of 2.13 $\pm$ 1.29% for somatropin related proteins by RP-HPLC. Estimates of relative potency by weight gain bioassay in the hypophysectomised rats showed that relative potency of KS 98/674 was 1.07 aganist IS 88/624. Based on the results of the collaborative study, the candidate reference standard for somatropin is suitable to serve as a KFDA reference standard for somatropin.

• 한국정보통신학회논문지
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• 제18권2호
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• pp.282-288
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• 2014

DGPS 기준국은 Differential GPS를 위한 GPS 보정정보를 생성하고 방송하는 역할을 하는 국가 인프라이다. 현재 한국에서는 과거 하드웨어 기반의 DGPS 기준국 시스템을 개선하고 고도화하기 위해 USCG에서 제안한 차세대 표준인 소프트웨어 기반 DGPS 기준국을 도입하여 운영하고 있다. 그러나 USCG에서 제안한 소프트웨어 기반의 DGPS 기준국은 그 형태만 소프트웨어 방식으로 변경되었을 뿐 본질적인 아키텍처는 상당부분 개선되지 않아 소프트웨어 기반으로 변경한 장점을 크게 살리지 못하고 있다. 본 논문에서는 보다 간결화된 구조가 요구되는 DGPS 기준국에서 사용될 수 있는, 기준국 소프트웨어와 감시국 소프트웨어가 통합된 새로운 소프트웨어 기반 해양 DGPS 기준국의 아키텍처를 설계하였다.

• Journal of Positioning, Navigation, and Timing
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• 제12권1호
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• pp.83-89
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• 2023

The Korea Augmentation Satellite System (KASS) system is a Satellite Based Augmentation System (SBAS) under development to provide APV-I SBAS service in the Republic of Korea. The KASS ground segment generates correction and integrity information for GPS measurements of KASS users using the accurate positions of KASS Reference Station (KRS) antenna phase centers. For this reason, the accuracy of KRS reference points through geodetic survey campaigns is one of the important factors for providing the KASS service in compliance with the required navigation performance. In order to obtain accurate positions, two geodetic survey campaigns were performed at several reference points, such as Mark, Center of Mast at Ground Level (CMGL), and Center of Hole in Top Plate (CHTP), of each KRS site using three different survey methods, the Virtual Reference Station (VRS), Flächen Korrektur Parameter (FKP), and raw data post-processing methods. By comparing and analyzing the results, the computed coordinates of the reference points were verified and Antenna Phase Center (APC) positions were calculated using KRS Antenna Reference Point (ARP) data, and the first KASS Site Acceptance Test (SAT#1) was performed successfully using the verified APC coordinates. After the first site survey activities, the KASS operators should maintain the coordinates with the required performance such that the overall KASS navigation performance commitment is guaranteed during the lifetime of 15 years. Therefore, the maintenance plan for the KRS antenna coordinates should be developed before the commissioning of KASS operation planned after 2023. Therefore, this paper presents a geodetic survey method selected for the maintenance activities and provides the rationale for using this method.

• 센서학회지
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• 제26권1호
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• pp.28-34
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• 2017

An NIR grism Si optical area sensor spectrometer with in-band reference wavelength is designed and fabricated. It is composed of a transmission type diffraction grating (spatial density 300 line/mm), a rectangular N-BK7 prism (apex angle 30 degree), NIR filter(cutoff wavelength 720 nm), an imaging convex lens(focal length 50 mm F1.8) and an IR modified DSLR camera (Canon EOS40D) of Si optical area sensor ($3,888{\times}2,592$ pixels, pixel size $5.710{\mu}m$). "In-band reference wavelength function" is implemented using non-dispersive 0th diffraction order optical beam. The NIR grism spectrometer is tested in a laboratory using a halogen lamp and a Neon lamp. And the spectrometer is used in an astronomy field for obtaining the planet Jupiter NIR spectrum. In-band reference wavelength i.e. un-deviation wavelength is 846 nm, an wavelength resolution is 0.3027 nm/pixel, an wavelength resolving power is 2,794 and an wavelength range is 650~1,000 nm.