• Bulletin of the Korean Mathematical Society
• /
• v.32 no.2
• /
• pp.221-231
• /
• 1995

Let $Z_1, Z_2, \ldots, Z_l$ be random set functions or intergrals. Then it is possible to discuss their products. In the case of random integrals, $Z_i$ is a random set function indexed y a family, $G_i$ say, of real valued functions g on $S_i$ for which the integrals $Z_i(g) = \smallint gdZ_i$ are well defined. If $g_i = \in g_i (i = 1, 2, \ldots, l) and g_1 \otimes \cdots \otimes g_l$ denotes the tensor product $g(s) = g_1(s_1)g_2(s_2) \cdots g_l(s_l) for s = (s_1, s_2, \ldots, s_l) and s_i \in S_i$, then we can defined $Z(g) = (Z_1 \times Z_2 \times \cdots \times Z_l)(g) = Z_1(g_1)Z_2(g_2) \cdots Z_l(g_l)$.

• Korean Journal of Veterinary Service
• /
• v.16 no.1
• /
• pp.65-69
• /
• 1993

A serological survey was conducted to detect the type of Leptospirosis in sows. Antigen(live antigen) tested were L.icterohemorrhagiae, L.pomonal, L.canicola, L.Hardjo, L.australis, L.autumnalis, L.grippotyphosa, L.pyrogens, L.bataviae, L.hebdomadis. The survey was performed from J one 1992 to December 1992 by microscopic-agglutination test. The results were as follows 1, Among the serum samples of 92 heads of the sows, 6 heads of the sow(6.5%) were positive. 2. Among the positive samples of 6 heads, L.icterihemorrhagiae were 4 heads(4.3%) and L. pomona 2 heads (2.2%), respectively. 3. Antibody titers of positive sera were ranging from 1：200 to 1：1600. 4. The seroprevalence of leptospira in Chechon city, Chechon county, Danyang county that Chechon county(3.3%) was higher than that of other districts(1% -2.2%).

• Korean Journal of Plant Resources
• /
• v.18 no.3
• /
• pp.450-455
• /
• 2005

This study was conducted to examine the effects of plant growth regulators on the plant regeneration from leaf segments of Lilium callosum, L. concolor var. partheneion, and L. formosanum. Leaf segments were sectioned about 5 mm long and cultured on the basal medium (MS medium with $3\%$ sucrose and $0.8\%$ agar) under dark condition, The most effective plant regulators on harvesting more shoots from leaf culture of L. callosum were $0.2\;mg{\cdot}L^{-1}\;BA$ and $0.5\;mg{\cdot}L^{-1}\;NAA$. Culturing in the basal medium with $0.2\;mg{\cdot}L^{-1}\;BA$ and $2.0\;mg{\cdot}L^{-1}\;NAA$ was effective for leaf culture of L. concolor var. partheneion. The treatment of $1.0\;mg{\cdot}L^{-1}\;BA$ and $1.0\;mg{\cdot}L^{-1}\;NAA$ was the most effective condition for shoot harvest at the leaf culture of L. formosanum.

• Bulletin of the Korean Mathematical Society
• /
• v.59 no.3
• /
• pp.697-707
• /
• 2022

It is well known that the continued fraction expansion of ${\sqrt{d}}$ has the form $[{\alpha}_0,\;{\bar{{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1},\;2_{{\alpha}_0}}]$ and ${\alpha}_1,\;{\ldots},\;{\alpha}_{l-1}$ is a palindromic sequence of positive integers. For a given positive integer l and a palindromic sequence of positive integers ${\alpha}_1,\;{\ldots},\;{\alpha}_{l-1},$ we define the set $S(l;{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1})\;:=\;\{d{\in}{\mathbb{Z}}{\mid}d>0,\;{\sqrt{d}}=[{\alpha}_0,\;{\bar{{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1},\;2_{{\alpha}_0}}],\;where\;{\alpha}_0={\lfloor}{\sqrt{d}}{\rfloor}\}.$ In this paper, we completely determine when $S(l;{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1})$ is not empty in the case that l is 4, 5, 6, or 7. We also give similar results for $(1+{\sqrt{d}})/2.$ For the case that l is 4, 5, or 6, we explicitly describe the fundamental units of the real quadratic field ${\mathbb{Q}}({\sqrt{d}}).$ Finally, we apply our results to the Mordell conjecture for the fundamental units of ${\mathbb{Q}}({\sqrt{d}}).$

• Geophysics and Geophysical Exploration
• /
• v.10 no.2
• /
• pp.124-130
• /
• 2007

Least squares ($l^2$ norm) solutions of seismic inversion tend to be very sensitive to data points with large errors. The $l^1$ norm minimization gives more robust solutions, but usually with higher computational cost. Iteratively reweighted least squares (IRLS) method gives efficient approximate solutions of these $l^1$ norm problems. I propose an efficient implementation of the IRLS method for a hybrid $l^1/l^2$ minimization problem that behaves as $l^2$ norm fit for small residual and $l^1$ norm fit for large residuals. The proposed algorithm shows more robust characteristics to the decision of the threshold value than the l1 norm IRLS inversion does with respect to the threshold value to avoid singularity.

• Korean Journal of Plant Resources
• /
• v.17 no.1
• /
• pp.1-6
• /
• 2004

Apical meristems tissue were cultured on LS medium with different zeatin and NAA concentrations to compare their potential to regenerate shoots, roots and bulblet formation. Shoot regeneration from apical meristem was effective on LS medium added with zeatin 0.1, 0.5, 1.0 mg/L alone treatment or zeatin 0.5 mg/L and NAA 1.0 mg/L combination treatment. A high frequency of root regeneration was obtained on LS medium supplemented with zeatin 0.5 mg/ and NAA 1.0 combination treatment. Linsmaier and Skoog(LS) medium with NAA 3.0 mg/L and zeatin 1.0 mg/L combination treatment gave the best results for normal bulblet formation#KW=Allium wakegi ; plant regeneration ; bulblet formation

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.2
• /
• pp.119-123
• /
• 1998

In order to investigate the possibility of in vitro mass propagation via somatic embryogenesis from Sicyos angulatus L., effects of plant growth regulators and carbon sources on callus induction and somatic embryogenesis were evaluated. Optimal combinations of plant growth regulator for callus induction from cotyledon and inflorescence explants were 2,4-D 2.0 mg/L + BA 0.1 mg/L and 2,4-D 1.0 mg/L + BA 0.1 mg/L in MS basal medium supplemented with sucrose 30 g/L,, respectively. Somatic embryogenesis was observed from cultured inflorescence explants, but it could not be achieved from leaf or cotyledon explants. The most effective plant growth regulators for somatic embryogenesis from callus was NAA 1.0 mg/L + kinetin 10 mg/L in the half strength of MS basal medium supplemented with 20 g/L sucrose.

• Phonetics and Speech Sciences
• /
• v.4 no.3
• /
• pp.31-41
• /
• 2012

Recent studies have shown that the stop system of Korean is undergoing a sound change in terms of the two acoustic parameters, voice onset time (VOT) and fundamental frequency (f0). Because of a VOT merger of a consonantal opposition and onset-f0 interaction, the relative importance of the two parameters has been changing in Korean where f0 is a primary cue and VOT is a secondary cue in distinguishing lax from aspirated stops in speech production as well as perception. In English, however, VOT is a primary cue and f0 is a secondary cue in contrasting voiced and voiceless stops. This study examines how Korean English learners use the two acoustic parameters of L1 in producing L2 English stops and whether the sound change of acoustic parameters in L1 affects L2 speech production. The data were collected from six adult Korean English learners. Results show that Korean English learners use not only VOT but also f0 to contrast L2 voiced and voiceless stops. However, unlike VOT variations among speakers, the magnitude effect of onset consonants on f0 in L2 English was steady and robust, indicating that f0 also plays an important role in contrasting the [voice] contrast in L2 English. The results suggest that the important role of f0 in contrasting lax and aspirated stops in L1 Korean is transferred to the contrast of voiced and voiceless stops in L2 English. The results imply that, for Korean English learners, f0 rather than VOT will play an important perceptual cue in contrasting voiced and voiceless stops in L2 English.

• Journal for History of Mathematics
• /
• v.27 no.1
• /
• pp.81-93
• /
• 2014

The $L^1$-convergence of Fourier series problems through additional assumptions for Fourier coefficients were presented by W. H. Young in 1913. We say that they are the classical results. Using modified trigonometric series is the convenience method to study the $L^1$-convergence of Fourier series problems. they are called the neoclassical results. This study concerns with the $L^1$-convergence of Fourier series. We introduce the classical and neoclassical results of $L^1$-convergence sequentially. In particular, we investigate $L^1$-convergence results focused on the results of Bhatia's studies. In conclusion, we present the research minor lineage of Bhatia's studies and compare the classes of $L^1$-convergence mutually.

• Speech Sciences
• /
• v.4 no.1
• /
• pp.91-112
• /
• 1998

This paper aimed at examining the influence of L1 (native language) phonology when speakers of L1 perceive L2 (foreign language) sounds. Korean and Japanese learners of English took a perception test of Australian English words 'work', 'walk' and 'wok'. Based on Korean and Japanese phonology, it was predicted that Korean subjects would face more difficulties than Japanese subjects. The results of the experiment substantiated the influence of L1 phonology in L2 learners' L2 sound perception.