• 제목/요약/키워드: Single Bias

검색결과 390건 처리시간 0.026초

Comparison of genome-wide association and genomic prediction methods for milk production traits in Korean Holstein cattle

  • Lee, SeokHyun;Dang, ChangGwon;Choy, YunHo;Do, ChangHee;Cho, Kwanghyun;Kim, Jongjoo;Kim, Yousam;Lee, Jungjae
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권7호
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    • pp.913-921
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    • 2019
  • Objective: The objectives of this study were to compare identified informative regions through two genome-wide association study (GWAS) approaches and determine the accuracy and bias of the direct genomic value (DGV) for milk production traits in Korean Holstein cattle, using two genomic prediction approaches: single-step genomic best linear unbiased prediction (ss-GBLUP) and Bayesian Bayes-B. Methods: Records on production traits such as adjusted 305-day milk (MY305), fat (FY305), and protein (PY305) yields were collected from 265,271 first parity cows. After quality control, 50,765 single-nucleotide polymorphic genotypes were available for analysis. In GWAS for ss-GBLUP (ssGWAS) and Bayes-B (BayesGWAS), the proportion of genetic variance for each 1-Mb genomic window was calculated and used to identify informative genomic regions. Accuracy of the DGV was estimated by a five-fold cross-validation with random clustering. As a measure of accuracy for DGV, we also assessed the correlation between DGV and deregressed-estimated breeding value (DEBV). The bias of DGV for each method was obtained by determining regression coefficients. Results: A total of nine and five significant windows (1 Mb) were identified for MY305 using ssGWAS and BayesGWAS, respectively. Using ssGWAS and BayesGWAS, we also detected multiple significant regions for FY305 (12 and 7) and PY305 (14 and 2), respectively. Both single-step DGV and Bayes DGV also showed somewhat moderate accuracy ranges for MY305 (0.32 to 0.34), FY305 (0.37 to 0.39), and PY305 (0.35 to 0.36) traits, respectively. The mean biases of DGVs determined using the single-step and Bayesian methods were $1.50{\pm}0.21$ and $1.18{\pm}0.26$ for MY305, $1.75{\pm}0.33$ and $1.14{\pm}0.20$ for FY305, and $1.59{\pm}0.20$ and $1.14{\pm}0.15$ for PY305, respectively. Conclusion: From the bias perspective, we believe that genomic selection based on the application of Bayesian approaches would be more suitable than application of ss-GBLUP in Korean Holstein populations.

슬관절 수술 후 재활에 대한 Continuous Passive Motion 치료와 한의 병행치료의 체계적 문헌 고찰 (A Systemic Review of Korean Medical Treatment Combined with Continuous Passive Motion Therapy on the Knee Joint Postoperative Rehabilitation)

  • 하현주;오민석
    • 한방재활의학과학회지
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    • 제27권3호
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    • pp.33-45
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    • 2017
  • Objectives The objective of this study is to report the evidence that continuous passive motion (CPM) therapy combined with Korean Medicine is effective for knee injuries. Methods We searched 2 Korean medical electronic databases, and 2 Chinese electronic databases to find randomized controlled clinical trials (RCTs) that treat knee injuries with Korean Medicine combined with CPM therapy. We selected studies by screening. We extracted data from selected RCTs, and analyzed RCTs by using Cochrane's Risk of bias criteria. Results 386 studies are searched, and 7 RCTs are selected. According to the study, several kinds of Korean Medicine such as hydrotherapy, decoction, acupuncture, moxibustion, and manual therapy are used with CPM therapy for the knee joint postoperative rehabilitation. We found the encouraging evidence that Korean Medicine and CPM combined therapy is more effective than single CPM therapy by alleviating pain, increasing range of motion, and improving knee function, etc. However, the risk of bias in most RCTs was judged to be uncertain. Conclusions Combination of Korean Medicine and CPM therapy can compensate the defect of single CPM therapy, and promotes the recovery of knee joint function.

Design Improvement and Measurement of a Rapid Single Flux Quantum Confluence Buffer

  • Baek, Seung-Hun;Kim, Jin-Young;Kim, Sehoon;Kang, Joonhee;Jungb, Ku-Rak;Park, Jong-Hyeok;Hahnb, Teak-Shang
    • 한국초전도ㆍ저온공학회논문지
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    • 제6권4호
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    • pp.41-45
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    • 2004
  • Rapid Single flux quantum (RSFQ) confluence buffer is widely used in complex superconductive digital circuits. In this work, we have improved the currently used confluence buffer and obtained a more soundly designed confluence buffer. In simulations, improvements in the bias margins of 11 % and the global margins of 10%, compared to the previously used confluence buffer, were achieved. Global margins are very important in estimating a process error range allowed in fabrications. We used two circuit simulation tools, WRspice and Julia, to design and optimize the confluence buffer. We used Xic to obtain a mask layout. We fabricated the improved circuits by using Nb technology. The test results at low frequency showed that the improved confluence buffer operated correctly and had a very wide main bias margin of +/-43% enhanced from +/-26% of the previously used confluence buffer.

강자성 공명에 의한 Exchange Bias 연구 (Exchange Bias Study by FMR Measurment)

  • 유용구;박남석;민성기;유성초
    • 한국자기학회지
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    • 제15권5호
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    • pp.265-269
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    • 2005
  • 강자성 공명 측정을 통하여 다양한 층 구성을 갖는 교환 바이어스 박막들의 교환 결합 특성에 대해 연구하였다. 공명자기장의 각도의존 실험을 통하여 일축방향이방성 자기장과 일축이방성 자기장을 구하여 분석하였다. NiFe 단일 박막과 비교하여 교환 바이어스된 NiFe/IrMn, IrMn/NiFe/IrMn, NiFe/IrMn/CoFe 박막들은 큰 일축방향이방성 자기장을 나타내었으며, 일축이방성 자기장 또한 큰 값을 나타내었다. 그러나 NiFe/Cu/IrMn의 경우, Cu의 두께가 두꺼울 때는 매우 작은 일축방향이방성 자기장을 나타내었으며, NiFe 단일 박막과 비슷한 크기의 일축이방성 자기장을 나타내었다. NiFe/IrMn/CoFe 박막의 경우 NiFe와 CoFe 강자성층들에 의해 두 개의 공명 자기장이 나타났다. 그 외에 공명 자기장의 선폭에 관한 분석이 교환 바이어스 특성과 연관하여 논의되어졌다.

Hop2 and Sae3 Are Required for Dmc1-Mediated Double-Strand Break Repair via Homolog Bias during Meiosis

  • Cho, Hong-Rae;Kong, Yoon-Ju;Hong, Soo-Gil;Kim, Keun Pil
    • Molecules and Cells
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    • 제39권7호
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    • pp.550-556
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    • 2016
  • During meiosis, exchange of DNA segments occurs between paired homologous chromosomes in order to produce recombinant chromosomes, helping to increase genetic diversity within a species. This genetic exchange process is tightly controlled by the eukaryotic RecA homologs Rad51 and Dmc1, which are involved in strand exchange of meiotic recombination, with Rad51 participating specifically in mitotic recombination. Meiotic recombination requires an interaction between homologous chromosomes to repair programmed double-strand breaks (DSBs). In this study, we investigated the budding yeast meiosis-specific proteins Hop2 and Sae3, which function in the Dmc1-dependent pathway. This pathway mediates the homology searching and strand invasion processes. Mek1 kinase participates in switching meiotic recombination from sister bias to homolog bias after DSB formation. In the absence of Hop2 and Sae3, DSBs were produced normally, but showed defects in the DSB-to-single-end invasion transition mediated by Dmc1 and auxiliary factors, and mutant strains failed to complete proper chromosome segregation. However, in the absence of Mek1 kinase activity, Rad51-dependent recombination progressed via sister bias in the $hop2{\Delta}$ or $sae3{\Delta}$ mutants, even in the presence of Dmc1. Thus, Hop2 and Sae3 actively modulate Dmc1-dependent recombination, effectively progressing homolog bias, a process requiring Mek1 kinase activation.

레이더 자료의 군집화를 통한 Mean Field Rainfall Bias의 보정 (Adjustment of the Mean Field Rainfall Bias by Clustering Technique)

  • 김영일;김태순;허준행
    • 한국수자원학회논문집
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    • 제42권8호
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    • pp.659-671
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    • 2009
  • 본 연구에서는 레이더 강우량 자료의 편차보정에 사용되는 G/R비의 정확도를 향상시키기 위하여 fuzzy c-means 방법을 사용한 자료의 군집화를 적용하였다. 대상 레이더자료는 광덕산 레이더기지의 자료로서 유효범위 100km이내의 자료를 대상으로 지상관측망인 기상청의 AWS(Automatic Weather System) 지점에서 관측한 자료와의 비교를 통하여 G/R비를 구하였다. G/R비를 구하는데 있어서 전체 유효범위를 대상으로 동일한 방법을 사용한 경우와 레이더 자료의 군집화를 통해서 지형적인 효과를 고려한 경우를 비교하였으며, AWS 실측강우량과 G/R비를 통한 레이더 강우량 자료의 비교를 위하여 절대상대오차와 평균제곱근오차 등을 비교분석하였다. 그 결과 전체유효범위를 대상으로 동일하게 G/R비를 적용하여 구한 레이더 강우량에 비하여 군집분석을 이용하여 지형효과를 고려한 G/R비를 적용한 레이더 강우량의 오차가 더 적게 나타났다.

Search for the preformed-pair state in the pseudogap regime above T$_c$ using c-axis tunneling in Bi$_2$Sr$_2$CaCu$_2$O$_{8+d}$ single crystals

  • Chang, Hyun-Sik;Lee, Hu-Jong;Oda, MigaKu;Jang, Eue-Soon;Ido, Masayuki;Choy, Jin-Ho
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.85-85
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    • 2000
  • The normal state of high-Tc superconducting materials has been believed to contain important clues to finding the correct mechanism of the high-Tc superconductivity. One example is the existence of pseudogap in the normal state even above Tc, as observed in various measurements such as photoemission spectroscopy and tunneling conductance. In this pseudogap regime the existence of preformed pairs only with local phase coherence has been debated. Recently Choi, Bang, and Campbell[1] have proposed the occurrence of the zero-bias conductance enhancement due to Andreev quasiparticle reflection from the preformed pairs even with the local phase coherence. In this study we examine the zero-bias enhancement of the differential conductance near or slightly above Tc, using c-axis tunneling in mesa structure of Bi2Sr20a0u208+d single crystals. In slightly overdoped samples zero-bias conductance enhancement (ZBCE) has been observed over a range of 2 K above Tc. In contrast, in underdoped samples with Tc${\sim}$72K the ZBCE appears over a range of 5-6 K above Tc, a much wider temperature range than in overdoped samples. This result may pose as positive signs of the existence of prefurmed pairs in the normal state of high- Tc superconducting materials.

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NiFe/MnIr 박막에서 교환 바이어스의 각도 의존성 연구 (Angular Dependence of Exchange Bias in NiFe/MnIr Bilayers)

  • 윤석수;김동영
    • 한국자기학회지
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    • 제27권1호
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    • pp.30-34
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    • 2017
  • 본 연구에서는 교환 결합력을 갖는 강자성/반강자성(AF) 박막에서 단자구 모델을 사용하여 교환 바이어스($H_{ex}$)의 각도 의존성을 계산하였으며, NiFe/MnIr 박막에서 측정한 결과와 비교 분석하였다. AF층 두께가 임계 두께 이상에서($t_{AF}$ > $t_c$) 계산한 $H_{ex}$의 각도 의존성은 전형적인 일방 이방성 특성을 보였으나, $0.5t_c$ < $t_{AF}$ < $t_c$에서는 $90^{\circ}$ 근처의 특정한 각도에서 AF 스핀의 고정에 의한 독특한 $H_{ex}$의 각도 의존성을 보였다. NiFe/MnIr(20 nm) 박막에서 측정한 $H_{ex}$의 각도 의존성은 전형적인 일방 이방성 특성을 보였으나, NiFe/MnIr(4 nm) 박막에서는 일방 이방성 특성과 AF 스핀의 고정에 의한 특성이 혼합된 결과를 보였으며, 이는 다결정 구조를 갖는 MnIr의 입도 분포 특성으로 설명되어짐을 알 수 있었다.

PCS 용 MMIC Single-blanced upconverting 주파수 혼합기 설계 및 제작 (A GaAs MMIC Single-Balanced Upconverting Mixer With Built-in Active Balun for PCS Applications)

  • 강현일;이원상;정기웅;오재응
    • 전자공학회논문지D
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    • 제35D권4호
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    • pp.1-8
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    • 1998
  • An MMIC single-balanced upconverting mixer for PCS application has been successfully developed using an MMIC process employed by 1 .mu. ion implanted GaAs MESFET and passive lumped elements consisting of spiral inductor, Si3N4 MIM capacitors and NiCr resistors. The configuration of the mixer presented in this paper is two balanced cascode FET mixers with common-source self-bias circuits for single power supply operation. The dimension of the fabricated circuit including two active baluns intermodulation characteristic with two-tone excitation are also measured, showing -28.17 dBc at IF power of -30 dBm.

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Isolated Power Supply for Multiple Gate Drivers using Wireless Power Transfer System with Single-Antenna Receiver

  • Lim, Chang-Jong;Park, Shihong
    • Journal of Power Electronics
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    • 제17권5호
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    • pp.1382-1390
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    • 2017
  • This paper presents a power supply for gate drivers, which uses a magnetic resonance wireless power transfer system. Unlike other methods where multiple antennas are used to supply power for the gate drivers, the proposed method uses a single antenna in an insulated receiver to make multiple mutually isolated power supplies. The power transmitted via single antenna is distributed to multiple power supplies for gate drivers through resonant capacitors connected in parallel that also block DC bias. This approach has many advantages over other methods, where each gate driver needs to be supplied with power using multiple receiver antennas. The proposed method will therefore lead to a reduction in production costs and circuit area. Because the proposed circuit uses a high resonance frequency of 6.78 MHz, it is possible to implement a transmitter and a receiver using a small-sized spiral printed-circuit-board-type antenna. This paper used a single phase-leg circuit configuration to experimentally verify the performance characteristics of the proposed method.