• Journal of Genetic Medicine
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• 제13권1호
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• pp.14-19
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• 2016

Purpose: We examined the prevalence and CGG/AGG repeat structure of expanded alleles of the FMR1 gene in preconceptional and pregnant Korean women. Materials and Methods: The CGG repeats in the FMR1 genes of 1,408 women were analyzed by polymerase chain reaction and Southern blot analysis. To estimate the prevalence of expansion alleles, the individuals were divided into low risk and high risk group. Results: Within this population, 98.4% had normal alleles and 1.6% had abnormal alleles including intermediate (0.6%), premutation (0.5%), full mutation (0.1%), and hemizygous (0.4%) alleles. There were 2 premutation alleles (1:666, 95% confidence interval [CI] 1:250-1,776) in the low risk group and 5 premutation alleles (1:15, 95% 1:6-36) in the high risk group. There were 8 intermediate alleles (1:167, 95% CI 1:130-213) in the low risk group and 1 intermediate alleles (1:76, 95% CI 1:11-533) in the high group. Six of the 7 premutation alleles did not contain AGG interruptions within the repeats and 1 had a single AGG interruption. Four of the 9 intermediate alleles contained 2-3 AGG, 4 had a single AGG, and 1 had no AGG interruptions. Conclusion: Our study demonstrates the prevalence and CGG/AGG structure of expansion alleles in Korean women. The identified premutation prevalence is higher than that of other Asian populations and lower than that of Caucasian populations. Although our study is limited by size and population bias, our findings could prove useful for genetic counseling of preconceptional or pregnant women.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2010년도 임시총회 및 하계학술연구발표회
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• pp.108-109
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• 2010

In summary, the FMR technique was applied to investigate the magnetic properties of Py thin films. Frequency dependence of the resonance field and line width was analyzed using Landau-Lifshitz-Gilbert equation.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.296.1-296.1
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• 2008

• 한국자기학회지
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• 제11권6호
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• pp.239-244
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• 2001

최근 연구가 활발히 진행되고 있는 RF 대역에서 사용가능한 인덕터를 제조하여 특성을 평가하였다. 인덕턴스와 Q값을 높이기 위하여 5000 두께의 F $e_{78.81}$T $a_{8.47}$ $N_{12.71}$ 연자성박막을 삽입하였으며, 자성박막의 FMR 공진주파수를 인위적으로 확장시키기 위하여 pattern을 형성시켜 shape anisotropy를 증가시켰다. 또한 코일부분은 lift-off process를 이용하여 제조하였다. 제조된 인덕터의 디자인은 4턴의 rectangular spiral형태였으며, 측정된 특성은 Ti/Ag air-core의 경우 5 GHz까가지 공진이 없었으며 2GHz에서 Q값이 9, 인덕턴스 8.4nH였다. 자성박막을 이용한 경우 9 nH에 공진주파수는 약 700 MHz부근이었다.다.

• 마이크로전자및패키징학회지
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• 제10권1호
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• pp.65-69
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• 2003

소결온도에 따른 아이솔레이터/서클레이터용 (Y, Ca)-(Fe, V, In, Al)-O 계 YIG 페라이트의 미세구조와 전자기적 특성을 고찰하였다. $Y_{2.1}Ca_{0.9}Fe_{4.4}V_{0.5}In_{0.05}Al_{0.05}O_{12}$ 조성의 시편들을 일반적인 세라믹 제조 공정에 따라 $1300^{\circ}C$, $1330^{\circ}C$, $1350^{\circ}C$, $1370^{\circ}C$에서 각각 소결하였다. 소결체는 XRD를 이용하여 상분석을 실시하였고, SEM을 이용하여 미세구조를 관찰하였다. VSM을 이용하여 포화자화값$(4{\pi}M_s)$을 측정하였으며, FMR(Ferromagnetic Resonance)실험으로 자기공명반치폭$({\Delta}H)$을 측정하였다. YIG 페라이트의 마이크로파 특성은 Network Analyzer를 이용하여 측정하였다. $Y_{2.1}Ca_{0.9}Fe_{4.4}V_{0.5}In_{0.05}Al_{0.05}O_{12}$ 조성의 YIG 페라이트는 $1350^{\circ}C$에서 소결시 가장 높은 밀도값과 포화 자화$(4{\pi}M_s)$ 값을 나타내었고, 가장 낮은 자기 공명 반치폭$({\Delta}H)$ 값을 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.620-625
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• 2005

Correlation of microsatellite heterozygosity with performance or heterosis was reported in wild animal populations and domestic animal populations, but the correlation with heterosis in a crossbreeding F$_1$ pig population remained uncertain. To explore this, we had random selected and mated Yorkshire${\times}$Meishan (F, n = 82) and their reciprocal (G, n = 47) to F$_1$, and used the two straightbreds as control groups (Yorkshire = 34, Meishan = 55), and observed the heterosis of birth weight (BWT), average daily gain (ADG) and feed and meat ratio (FMR). Two Kinds of measurement-individual heterozygosity (IH) and individual mean d$^2$ (lg value, ID) were used as index of heterozygosity and variance from 39 microsatellite marker loci to perform univariate regression analysis against heterosis. We detected significant correlation of IH with BWT in all of F$_1$ (F+G) and in F. We observed significant correlation of ID with ADG in all of F$_1$ (F+G), and with FMR in all of F$_1$ (F+G) and in F. There was significant maternal effect on heterosis, which was indicated by significant difference of means and distribution of heterosis between F and G. This difference was consistent with distributions of IH and ID, and with difference of means in F and G. From this study, it would be suggested that the two kinds of genetic index could be used to explore the genetic basis of heterosis in crossbreeding populations but could not determine which is better.

• 한국자기학회지
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• 제25권3호
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• pp.74-78
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• 2015

본 연구에서는 교환 결합력을 갖는 CoFe/MnIr 박막 재료에서 강자성 공명 장치를 이용하여 자기장 방향에 따른 저자장 마이크로파 흡수(Low field microwave absorption, LFMA) 및 강자성 공명 신호를 측정하였다. 낮은 자기장 영역에서 나타나는 LFMA 신호는 자구의 회전 밀접하게 관계됨을 자화 곡선으로부터 알 수 있었다. 이러한 LFMA 신호 특성을 분석하기 위하여 강자성 공명 신호로부터 측정한 교환 바이어스($H_{ex}$ = 58.5 Oe) 및 일축 이방성 자기장($H_k$ = 30Oe)을 S-W model에 적용하여 자화과정의 횡방향 자화량(transverse magnetization, $M_{\tau}$) 및 투자율(transverse susceptibility, ${\mu}_{\tau}$)을 계산하였다. 자화 곤란축에서 측정된 LFMA 신호는 $M_{\tau}$ 비례하는 경향을 보였지만, 자화 곤란축과 수직 방향으로 접근하면 $M_{\tau}$ 및 ${\mu}_{\tau}$ 모두에 의존하는 특성을 보였다.

• 한국자기학회지
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• 제9권1호
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• pp.7-16
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• 1999

본 연구에서는 화학량론적 YIG(yttrium iron garnet : Y3Fe5O12)를 중심으로 하여 조성에 따른 비화학량론적인 YIG(Y3-xFe5+xO12)를 고상반응법으로 제작하고 5.11GHz(G-band)와 23.39 GHz(K-band)의 마이크로파 영역에서 강자성 공명 현상을 이용하여 자기적 특성을 조사하였다. 측정된 분광학적 분리상수 g는 2.02~2.35이다. 포화자화와 유효자화의 값은 x=-0.05의 조성비를 중심으로 이트륨(Y3+)초과와 철(Fe3+)이 초과함에 따라 감소하는 경향을 보였으며, 이와 반대로 선폭( p-p)은 급격히 증가하였다. 자기적 특성의 온도 의존성을 조사하기 위해 K-band에서 80K에서 상온까지 공명흡수선을 측정하여 조성에 따른 M(0), Bloch 상수 B, C 및 스핀파 경도상수 D(약 162~206eV$\AA$2)와 교환상호작용의 평균자승 영역(약 5.84~12.13$\AA$2)의 변화를 조사하였다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 추계학술대회 논문집
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• pp.61-62
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• 2007

HVOF thermal spray coating of micron size Co-alloy powder has been studied for the durability improvement of high velocity spindle (HVS). Optimal coating process of this system for the best surface properties is hydrogen flow rate 75 FMR, oxygen flow rate 38-42 FMR, feed rate 30 g/min at spray distance 5 inch. Friction coefficient (FC) and wear trace (WT) decrease increasing coating surface temperature from 25$^{\circ}$C to 538$^{\circ}$C due to the higher lubricant effects of the oxides at the higher temperature. At the study of adhesion of T800 coating on a light metal alloy Ti-6Al-4V (Ti64) tensile bond strength (TBS) and tensile fracture location (TFL) of Ti64/T800 are 8,740 psi and near middle of T800 coating respectively. This shows that adhesion of Ti64/T800 is higher than the cohesion strength (8,740 psi) of T800 coating. Therefore T800 coating is strongly advisable for the surface coating on HVS such as high speed air-bearing spindle.

• 한국표면공학회지
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• 제40권4호
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• pp.170-174
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• 2007

High Velocity Oxygen Fuel (HVOF) thermal spray coating of nano size WC-Co powder (nWC-Co) has been studied as one of the most promising candidate for the possible replacement of the traditional hard plating in some area which causes environmental and health problems. nWC-Co powder was coated on Inconel 718 substrates by HVOF technique. The optimal coating process obtained from the best surface properties such as hardness and porosity is the process of oxygen flow rate (FR) 38 FMR, hydrogen FR 57 FMR and feed rate 35 g/min at spray distance 6 inch for both surface temperature $25^{\circ}C\;and\;500^{\circ}C$. In coating process a small portion of hard WC decomposes to less hard $W_2C$, W and C at the temperature higher than its decomposition temperature $1,250^{\circ}C$ resulting in hardness decrease and porosity increase. Friction coefficient increases with increasing coating surface temperature from 0.55-0.64 at $25^{\circ}C$ to 0.65-0.76 at $500^{\circ}C$ due to the increase of adhesion between coating and counter sliding surface. Hardness of nWC-Co is higher or comparable to those of other hard coatings, such as $Al_2O_3,\;Cr,\;Cr_2O_3$ and HVOF Tribaloy 400 (T400). This shows that nWC-Co is recommendable for durability improvement coating on machine components such as high speed spindle.