• 대한수학회보
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• 제55권5호
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• pp.1317-1332
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• 2018

In this paper, we introduce the D-ratio of a rational map $f:{\mathbb{P}}^n{\dashrightarrow}{\mathbb{P}}^n$, defined over ${\bar{\mathbb{Q}}}$, whose indeterminacy locus is contained in a hyperplane H on ${\mathbb{P}}^n$. The D-ratio r(f; ${\bar{V}}$) characterizes endomorphisms and provides a useful height inequality on ${\mathbb{P}}^n({\bar{\mathbb{Q}}}){\backslash}H$. We also provide a dynamical application: preperiodic points of dynamical systems of small D-ratio are of bounded height.

• Kyungpook Mathematical Journal
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• 제18권1호
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• pp.105-107
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• 1978

Considering the prime z-filters on a topological space X through the structures of the ring C(X) of continuous functions. a prime z-filter is uniquely determined by a primary z-ideal in the ring C(X), i. e., they have a one-to-one correspondence. Any primary ideal is contained in a unique maximal ideal in C(X). Denoting $\mathfrak{F}(X)$, $\mathfrak{Q}(X)$, 𝔐(X) the prime, primary-z, maximal spectra, respectively, $\mathfrak{Q}(X)$ is neither an open nor a closed subspace of $\mathfrak{F}(X)$.

• 산업경영시스템학회지
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• 제14권24호
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• pp.23-30
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• 1991

This study aimed at the improvement of the conventional methods of VE Function Analysis, the most important phase of VE process, through Quality Function Development. The use of Function Requirement Coefficients in Quality Function Development makes the Function Development more objective, and it was found that VE techniques, when used in combination with QC techniques. Improve the value of product considerably.

• 한국지구과학회지
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• 제24권8호
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• pp.684-690
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• 2003

최근 새로운 행정수도의 이전이 예상된 남한 중부 충청지방에 대한 관심이 고조되고 있다. 우리는 이 지역에서 1996년 9월 이후 한국교원대학교 지진관측망을 설치하석 운영 중이며, 이 관측망 중 2개 관측소에서 기록된 60개의 지진자료를 바탕으로 확장 Coda 규격화법을 이용하여 Q$_P^{-1}$ 과 Q$_S^{-1}$을 동시에 측정하였다. 부족한 자료를 보충하기 위해서 한국지질자원연구원 관측망 중 한국교원대학교 관측망과 지리적으로 인접한 1개의 관측소에서 기록된 33개의 지진자료도 함께 분석하였다. 측정된 Q$_P^{-1}$은 (1.9${\pm}$3.0)${\times}$10$^{-3}$에서 (5.4${\pm}$1.5)${\times}$10$^{-4}$으로, Q$_S^{-1}$은 (2.4${\pm}$1.4)${\times}$10$^{-3}$에서 (6.3${\pm}$1.1)${\times}$10$^{-4}$으로 주파수가 3.0Hz에서 24Hz로 늘어남에 따라 줄어드는 주파수 의존적 특성을 보인다. 이 값을 주파수의 지수형태로 나타내면 Q$_P^{-1}$=0.003f^{-0.62}$, Q$_S^{-1}$=0.006f$^{-0.071}$이다. 이 값들은 지진학적으로 안정한 전 세계의 다른 지역의 값과 유사하며 남한 남동부 지역값에 비해서는 다소 약한 주파수 의존을 나타낸다. 이는 고주파수에서 높은 Q$^{-1}$값 때문이다. 남한 남동부와 충청 동부지역 간의 Q$^{-1}$의 차이를 평가하기 위해서는 보다 많은 관측이 요구된다.

• 한국농공학회지
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• 제18권2호
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• pp.4116-4120
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• 1976

With the use of many rivers increased nearly to the capacity, the need for information concerning daily quantities of water and the total annual or seasonal runoff has became increased. A systematic record of the flow of a river is commonly made in terms of the mean daily discharge Since. a single observation of stage is converted into discharge by means of rating curve, it is essential that the stage discharge relations shall be accurately established. All rating curves have the looping effect due chiefly to channel storage and variation in surface slope. Loop rating curves are most characteristic on streams with somewhat flatter gradients and more constricted channels. The great majority of gauge readings are taken by unskilled observers once a day without any indication of whether the stage is rising or falling. Therefore, normal rating curves shall show one discharge for one gauge height, regardless of falling or rising stage. The above reasons call for the correction of the discharge measurements taken on either side of flood waves to the theoretical steady-state condition. The correction of the discharge measurement is to consider channel storage and variation in surface slope. (1) Channel storage As the surface elevation of a river rises, water is temporarily stored in the river channel. There fore, the actual discharge at the control section can be attained by substracting the rate of change of storage from the measured discharge. (2) Variation in surface slope From the Manning equation, the steady state discharge Q in a channel of given roughness and cross-section, is given as {{{{Q PROPTO SQRT { 1} }}}} When the slope is not equal, the actual discharge will be {{{{ { Q}_{r CDOT f } PROPTO SQRT { 1 +- TRIANGLE I} CDOT TRIANGLE I }}}} may be expressed in the form of {{{{ TRIANGLE I= { dh/dt} over {c } }}}} and the celerity is approximately equal to 1.3 times the mean watrr velocity. Therefore, The steady-state discharge can be estimated from the following equation. {{{{Q= { { Q}_{r CDOT f } } over { SQRT { (1 +- { A CDOT dh/dt} over {1.3 { Q}_{r CDOT f }I } )} } }}}} If a sufficient number of observations are available, an alternative procedure can be applied. A rating curve may be drawn as a median line through the uncorrected values. The values of {{{{ { 1} over {cI } }}}} can be yielded from the measured quantities of Qr$.$f and dh/dt by use of Eq. (7) and (8). From the 1/cI v. stage relationship, new vlues of 1/cI are obtained and inserted in Eq. (7) and (8) to yield the steady-state discharge Q. The new values of Q are then plotted against stage as the corrected steadystate curve.

• 농업과학연구
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• 제41권1호
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• pp.1-7
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• 2014

Ratooning ability is one of the major different traits from perennial to cultivated rice and annual type. We developed a set of 126 introgression lines derived from a cross between Hwayeong and W1944 (O. rufipogon) to gain an insight into the genetic factors underlying differences between common wild rice and cultivated rice. One IL, CR6 among the 126 ILs of $BC_3F_4$ showed a significant difference in rationing ability compared with Hwayeong. To further characterize the rationing ability, CR6 was selected and crossed to Hwayeong to produce three secondary populations, $BC_4F_2$, $BC_4F_3$ and $BC_5F_2$. In the Hwayeong background, the W1944 allele was associated with an increase in rationing ability. QTL analysis showed that the qRAT5 for rationing ability was linked to RM194 ($R^2$=6.6%, 19.6%, and 44.5% in the $BC_4F_2$, $BC_5F_2$, and $BC_5F_3$, respectively). The putative qRAT5 was also tightly linked to QTLs for spikelets per panicle and grain weight indicating that this region harbors a QTL cluster related to domestication. To our knowledge, this is the first report to map the major QTL for ratooning ability in rice. The SSR markers linked to qRAT5 would be useful in marker-assisted selection for breeding lines with enhanced ratooning ability.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.26-26
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• 2017

Seed germination stimulated by light is said to be photoblastism. Photoblastism has not been reported in cereal crops, especially in the rice, but Korean weedy rice was reported to have photoblastism and longer mesocotyl than cultivar. Photoblastic weedy rice (PBR) was used to identify QTLs for photoblastism and mesocotyl length. In previous works, QTLs for photoblastism, pbr1 and pbr12 were identified on chromosomes 1 and 12 using 124 F4 lines from a cross between Ilpum and PBR using bulked segregant analysis. Two QTLs for mesocotyl elongation, qMel-1 and qMel-3 were mapped on chromosomes 1 and 3 120 F8 lines from the same cross. Of interest, the RM8260-RM246 region of pbr1 overlapped with a region of qMel-1. To know whether these two QTLs are functionally related, 110 F3 lines were developed from a cross between Ilpum and CR7124. CR7124 having photoblastism and long mesocotyl was selected from 120 F8 lines. 95 F3 lines were measured for germination rate in a light and dark condition and mesocotyl length. Mesocotyl length and germination rate in the dark condition in F3 lines showed significant correlation (r = 0.7, P < 0.0001). 95 $F_3$ lines were genotyped with RM7419 on chromosome 1. ANOVA showed that RM7419 was tightly linked to QTLs for photoblastism as well as mesocotyl length on chromosome 1 (P < 0.0001) indicating the tight linkage of two QTLs. Fine mapping of the two QTL is underway to analyze their functional relationship.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.139-142
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• 2003

Microwave dielectric properties of $Ca(Li_{1/4}Nb_{3/4})O_3-CaTiO_3$ ceramic systems were investigated with calcination temperatures and amounts of $CaTiO_3$ in the range of 0.2 to 0.4mol. $Ca(Li_{1/4}Nb_{3/4})O_3$ ceramics having orthorhombic crystal structure could be synthesized at $750^{\circ}C$ and sintered well at $1250^{\circ}C$. They showed the dielectric constant of 26, quality factor($Q{\times}f_o$) of 13,000 and temperature coefficient of resonant frequency(${\tau}_f$) of $-49{\pm}2ppm/^{\circ}C$ With adding the $CaTiO_3$ amount the dielectric constant and ${\tau}_f$ increased due to the solute of $CaTiO_3$ but the quality factor decreased. The 0.7$Ca(Li_{1/4}Nb_{3/4})O_3-0.3CaTiO_3$ ceramic showed the dielectric constant of 44, quality factor($Q{\times}f_o$) of 12,000 and ${\tau}_f$ of $-9{\pm}1ppm/^{\circ}C$.

• 한국세라믹학회지
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• 제38권11호
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• pp.1042-1045
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• 2001

Ba(Zn$_{1}$3/Nb$_{2}$3/) $O_3$-Sr(Zn$_{1}$3/Nb$_{2}$3/) $O_3$계에 대하여 소결 온도 변화와 Zr $O_2$첨가량에 따른 마이크로파 유전특성을 조사하였다. 동일 조성에서 소결 온도가 증가함에 따라 밀도가 향상되고 공진 주파수의 온도계수($ au$$_{f}$)는 감소하는 경향을 보였으나, 유전상수(K)와 품질계수(Q$\times$f)는 커다란 변화가 없었다. 또한 Zr $O_2$첨가량이 증가함에 따라 소결 시편의 밀도가 향상되었고 더불어 유전상수, 품질계수가 증가하는 경향을 보였으며, 공진 주파수의 온도계수가 감소하는 우수한 특성이 나타났다. 특히, 소결온도 1575$^{\circ}C$, 0.6 wt% Zr $O_2$를 첨가했을 때 유전상수가 최대($\varepsilon$$_{r}$=41)로 나타났으며, 공진 주파수의 온도계수는 1.0wt% Zr $O_2$를 첨가했을 때 최소($\tau$$_{f}$=+0.8ppm/$^{\circ}C$)로서 양호한 값을 얻을 수 있었다.었다.

• 대한수학회보
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• 제48권6호
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• pp.1303-1314
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• 2011

We consider meromorphic solutions of q-difference equations of the form $$\sum_{j=o}^{n}a_j(z)f(q^jz)=a_{n+1}(z),$$ where $a_0(z)$, ${\ldots}$, $a_{n+1}(z)$ are meromorphic functions, $a_0(z)a_n(z)$ ≢ 0 and $q{\in}\mathbb{C}$ such that 0 < |q| ${\leq}$ 1. We give a new estimate on the upper bound for the length of the gap in the power series of entire solutions for the case 0 < |q| < 1 and n = 2. Some growth estimates for meromorphic solutions are also given in the cases 0 < |q| < 1. Moreover, we investigate zeros and poles of meromorphic solutions for the case |q| = 1.