• Journal of the Korean Mathematical Society
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• 제32권2호
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• pp.161-170
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• 1995

A complex $n(\geq 2)$-dimensional Kaehlerian manifold of constant holomorphic sectional curvature c is called a complex space form, which is denoted by $M_n(c)$. A complete and simply connected complex space form is a complex projective space $P_nC$, a complex Euclidean space $C^n$ or a complex hyperbolic space $H_nC$, according as c > 0, c = 0 or c < 0. Takagi [12] and Berndt [2] classified all homogeneous real hypersufaces of $P_nC$ and $H_nC$.

• The Bulletin of The Korean Astronomical Society
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• 제31권1호
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• pp.39.1-39.1
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• 2006

• The Korean Journal of Physiology
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• 제5권2호
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• pp.41-44
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• 1971

Thiocyanate space was determined in 23 bilaterally nephrectomized rabbits in acute metabolic acidosis and alkalosis. Acid-base disturbances were induced by the infusion of 0.3 N HCI or 0.3 N NaOH solution intravenously with the rate of 1 ml/min for 40 to 60 minutes. The blood pressure was monitored throughout the experiment and no changes in blood pressure was confirmed. The following results were obtained. 1. In the saline infused control rabbits, PH was 7.385 with negligible change in pH after the infusion, SCN space was 23.6% of body weight. 2. In the metabolic acidosis group, pH dropped from 7.417 to 7 130 and SCN space was 22.8% of body weight and suggested a negligible change in the extracellular space volume. 3. In the metabolic alkalosis group, pH increased from 7.393 to 7.478 and SCN space was 25.7% of body weight which confirmed a significant increase in the extracellular space volume.

• Communications of the Korean Mathematical Society
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• 제18권4호
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• pp.653-659
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• 2003

Let $1{\;}\leq{\;}p{\;}\infty{\;}and{\;}{\alpha}{\;}>{\;}-1$. If f is a holomorphic self-map of the open unit disc U of C with f(0) = 0, then the quantity $\int_U\;\{\frac{$\mid$f'(z)$\mid$}{1\;-\;$\mid$f(z)$\mid$^2}\}^p\;(1\;-\;$\mid$z$\mid$)^{\alpha+p}dxdy$ is equivalent to the operator norm of the composition operator $C_f{\;}:{\;}B{\;}\rightarrow{\;}A^{p,{\alpha}$ defined by $C_fh{\;}={\;}h{\;}\circ{\;}f{\;}-{\;}h(0)$, where B and $A^{p,{\alpha}$ are the Bloch space and the weighted Bergman space on U respectively.

• Publications of The Korean Astronomical Society
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• 제23권2호
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• pp.47-52
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• 2008

We have performed the flat-fielding correction for the $H{\alpha}$ full-disk monitoring system of KASI (Korea Astronomy and Space Science Institute), which is installed in the Solar Flare Telescope (SOFT) at the top of Bohyun Mountain. For this, we used a new method developed by Chae (2004), to determine the flat pattern from a set of relatively shifted images. Using this method, we successfully obtained the flat pattern for $H{\alpha}$ full-disk observations and compared our result with the image observed in Catania Astrophysical Observatory. The method that we used in this study seems to be quite powerful to obtain the flat image for solar observations. In near future, we will apply this method for the flat-fielding correction of all solar imaging instruments in KASI.

• The Bulletin of The Korean Astronomical Society
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• 제35권1호
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• pp.51.1-51.1
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• 2010

We present the interim results of simultaneous observations of SiO and H2O masers toward 401 known stellar SiO and/or H2O maser sources (166 both SiO and H2O maser sources, 83 only SiO maser sources, and 152 only H2O maser sources) using KVN_Yonsei telescope. The results of 166 known SiO/H2O maser sources will be presented by Kim et al. and the results of 83 only SiO maser sources and 152 only H2O maser sources presented here. Both SiO and H2O maser emission were detected from 30 sources giving a detection rate of 36 % toward known 83 only SiO maser sources, while they were detected from 66 sources giving a detection rate of 43 % toward known 152 only H2O maser sources at one epoch observation. Only SiO masers were detected from 42 sources toward 83 only SiO sources, while they were detected from 28 sources toward 152 only H2O sources. Characteristics of these observed sources in the IRAS two-color diagram is investigated including mutual relations between SiO and H2O maser emission. In addition, these results will be useful for statistical study of late-type stars and future VLBI observations.

• Phonetics and Speech Sciences
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• 제10권2호
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• pp.15-24
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• 2018

Earlier studies reported that the /o/ and /u/ phonemes of Seoul Korean were currently merging in the F1/F2 space. However, studies on perception tests have shown that rates of correctness were high, even in cases where the two vowels overlapped. This study explores whether there is another acoustic parameter that differentiates /o/ from /u/, besides the F1/F2 contrast. Seventy-five native speakers of Seoul Korean, born between 1953 and 1999, participated in a production test. The data collected were analyzed in terms of F1 and F2, H1-H2, and F0. The result shows that the /o/ and /u/ of female speakers almost overlap in the F1/F2 space for all ages, while H1-H2 values are significantly different between the two vowels regardless of age. On the other hand, the /o/ and /u/ of male speakers are largely well separated in the F1/F2 space, while the H1-H2 values between the two vowels are very close at all ages. F0 effect is relatively small for both male and female speakers, even though there is a statistically significant difference. The result of this study provides evidence that female speakers use phonation differences to distinguish /o/ from /u/, and that the F1/F2 contrast has been replaced by H1-H2 values.

• Bulletin of the Korean Mathematical Society
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• 제34권1호
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• pp.19-28
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• 1997

Let $H$ and $K$ be separable, complex Hilbert spaces and $L(H, K)$ denote the space of all linear, bounded operators from $H$ to $K$. If $H = K$, we write $L(H)$ in place of $L(H, K)$. An operator $T$ in $L(H)$ is called hyponormal if $TT^* \leq T^*T$, or equivalently, if $\left\$\mid$ T^*h \right\$\mid$ \leq \left\$\mid$ Th \right\$\mid$$ for each h in $H$. In [Pu], M. Putinar constructed a universal functional model for hyponormal operators.

• Publications of The Korean Astronomical Society
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• 제21권2호
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• pp.51-59
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• 2006

We have successfully developed the KASI (Korea Astronomy and Space Science Institute) Solar Imaging Spectrograph (KSIS), which has been originally upgraded from the KASI solar spectrograph that was able to record solar spectra for a given slit region and to inspect the response function of narrow band filters. A prototype KSIS was developed in 2004 by using a scanning mirror in front of the spectrograph slit and a SBIG ST-8XE CCD camera. Its main disadvantage is that it took a long time (about 13 minutes) to scan a whole active region. In this work, we have upgraded the KSIS by installing a much faster Dalsa 1M15 CCD camera, which gives a data acquisition time of about 2.5 minutes. The software for KSIS was also improved for the new CCD camera on the basis of component-based development method. We have successfully made a test observation for a simple and small active region (AR10910) using the improved KSIS system. Our observations show that H-alpha images for several wavelengths have typical features in a sunspot as well as a H-alpha centerline image is quite similar to a BBSO H-alpha image, demonstrating the capability of the KSIS system.

• The Bulletin of The Korean Astronomical Society
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• 제41권1호
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• pp.43.1-43.1
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• 2016

With the Korean VLBI Network (KVN), both single dish and VLBI monitoring observations of H2O and SiO masers were performed toward the semi-regular variable star R Crateris. In the case of 11 VLBI monitoring observations from Jan. 5, 2014 to Jan. 7, 2016, successful superposed maps of H2O and SiO masers were obtained at 7 epochs by adopting the Source Frequency Phase Referencing (SFPR) method. These results enable us to investigate the development of outflow and asymmetric motions from SiO maser to H2O maser regions according to stellar pulsation which are closely related with a mass-loss process. Single dish monitoring observations of H2O and SiO masers were also carried out from 2009 June to 2016 Feb. Intensity variations between H2O and SiO masers were investigated according to stellar optical phases together with peak velocity variations with respect to the stellar velocity. We will compare the VLBI results among different maser transitions with those of single dish.