• Progress in Superconductivity
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• v.10 no.1
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• pp.6-11
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• 2008

Multi-channel magnetocardiography (MCG) has been proposed to detect ischemic heart disease because its sensitivity is quite high comparing with other conventional diagnostic tools. Especially, current map and magnetic field map of MCG provide crucial information on whether myocardiac muscles maintain the normal conduction pathway. In addition, MCG parameters derived from repolarization are useful to detect coronary artery disease. Recently, there was a study reporting that R- and T- wave amplitude are highly correlated with ischemic heart disease. In this study, we studied R- and T-wave amplitude and their ratio as well as MCG parameters. MCG data from 20 young, 20 age-matched controls, and 20 myocardial infarction (MI) patients were analyzed. As a result, MCG parameters showed significant change in MI patients comparing to those of controls. R- and T-wave amplitude of MI patients showed a feature of severe ischemic heart disease even though it was difficult to find consistent values. Further study is needed to reveal the relations between small T-wave amplitude and coronary artery disease.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.225-231
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• 1999

Let Mf(x) be the Hardy-Littlewood maximal function on $\mathbb{R}^n$. Let $\Phi$ and $\Psi$ be functions satisfying $\Phi$(t) = ${\int^t}_0$a(s)ds and $\Psi(t)$ = ${\int^t}_0$b(s)ds, where a(s) and b(s) are positive continuous such that ${\int^\infty}_0\frac{a(s)}{s}ds$ = $\infty$ and b(s) is quasi-increasing. We show that if there exists a constant $c_1$ so that ${\int^s}_0\frac{a(t)}{t}dt\;c_1b(c_1s)$ for all $s\geq0$, then there exists a constant $c_1$ such that(0.1) $\int_{\mathbb{R^{n}}$ $\Phi(Mf(x))dx\;\leq\;c_2$ $\int_\mathbb{R^{n}}$$\Psi(c_2\midf(x)\mid)dx$ for all $f\epsilonL^1(R^n_$. Conversely, if there exists a constant $c_2$ satisfying the condition (0.1), then there exists a constant $c_1$ so that ${\int^s}_\delta\frac{a(t)}{t}dt=;\leq\;c_1b(c_1s$ for all $\delta$ > 0 and $s\geq\delta$.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.447-455
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• 1999

Allyl (5R)-(Z)- and (5R)-(E)-6-[(2S)-2,3-isopropylidenedioxypropylidene]Penicillanate(10a and 10b) were prepared from allyl (5R)-dibromopenicillanate(6) via a sequence of reactions involving condensation with 2,3-O-isopropylidene-D-glyceraldehyde, reduction with $Zn-NH_4OAc$, and Mitsunobu elimination. Deprotection of isopropylidene and allyl groups of 10a gave potassium (5R)-(Z)-6-[(2S)-2,3-dihydroxypropylidene]penicillanate(4). However, deprotection of isopropylidene group of 10b afforded ${\alpha},\;{\beta}$-unsaturated-lactone(12). Allyl (5R)-(Z)- and (5R)-(E)-6-[(2S)-2-(t-butyldimethlsilyloxy)propylidene]penicillanate(18a and 18b) were prepared from ally (5R)-dibromopenicillanate(6) via a sequence of reactions involving condensation with (2S)-2-(t-butyldimethylsilyloxy)propanal(15), reduction with $Zn-NH_4OAc$ and Mitsunobu elimination or mesylation-elimination. Deprotection of t-butyldimethylsilyl and allyl groups of 18a and 18b gave potassium (5R)-(Z)- and (5R)-(E)-6-[(2S)-2-hydroxypropylidene]penicillanate(5a and 5b), respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.11
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• pp.2103-2108
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• 2017

For n points $p_i$ on the m-dimensional plane $R^m$ and a fixed range r, consider a set $T_i$ containing points the distances from $p_i$ of which are less than or equal to r. In case m=1, $T_i$ is an interval on a line, it is a circle on a plane when m=2. For the vertices corresponding to the sets $T_i$, there is an edge between the vertices if the two sets intersect. Then this graph is called an intersection graph G. For m=1 G is called a proper interval graph and for m=2, it is called an unit disk graph. In this paper, we are concerned in the intersection graph G(r) when r changes. In particular, we consider the problem to find the minimum r such that G(r)is connected. For this problem, we propose an O(n) algorithm for the proper interval graph and an $O(n^2{\log}\;n)$ algorithm for the unit disk graph. For the dynamic environment in which the points on a line are added or deleted, we give an O(log n) algorithm for the problem.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.248-261
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• 2021

Scientific and technological performances (e.g., patents and publications) made through R&D play a pivotal role for national economic growth. National governments encourage academia-industry cooperation and thereby pursue continuous development of science technology and innovation. Increasing R&D-related investments and manpower are crucial for national industrial development, but evidence of poor performance in business performance, efficiency, and effectiveness has recently been found in Korea. This study evaluates performance efficiency of the 6T sector (Information Technology, Bio Technology, Nano Technology, Space Technology, Environment Technology, Culture Technology), which is considered a high-potential promising industry for the next generation growth and currently occupies two thirds of the national R&D projects. The study measures the relative efficiency of R&D in a comparative perspective by employing the Data Envelopment Analysis (DEA) method. The result reveals overall low efficiency in basic R&D (0.2112), applied R&D (0.2083), development R&D (0.2638), and others (0.0641), confirming that economic performance and efficiency were relatively poor compared to production efficiency. Efficient R&D needs policy makers to create strategies that can increase overall efficiency by improving productivity performance and quality while increasing economic performance.

• Communications of the Korean Mathematical Society
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• v.9 no.2
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• pp.303-315
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• 1994

Let X be a real Banach space with norm ∥ㆍ∥. Let T > 0, r ≥a be fixed constants. We denote by L/sup p/ the usual L/sup p/( -r, 0; X) with norm ∥ㆍ∥/sub p/ for 1 ≤p < ∞. Our object is to study the existence of solutions of nonlinear functional evolution equations of the type (FDE) x'(t) ＋ A(t)x(t) = G(t, x/sub t/), 0 ≤t ≤T, x/sub 0/ = ø.(omitted)

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.539-546
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• 2016

In this paper, the effect of J-R curve changes on the determination of parameters in a failure model owing to the presence or absence of a side groove in a C(T) specimen is investigated. A stress-modified fracture strain model is implemented for FE damage simulations. C(T) specimens were taken from SA508 grade 1a low-alloy steel piping material, and some of them were processed with a side groove. Fracture toughness tests were performed at room temperature and at $316^{\circ}C$. The parameters of the failure model were determined by damage simulations using the J-R curves obtained from the tests. Finally, the results show that the determination of failure model parameters is not affected by variations in J-R curves owing to the presence or absence of a side groove.

• The Pure and Applied Mathematics
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• v.4 no.1
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• pp.93-96
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• 1997

An atomic integral domain R is a half-factorial domain (HFD) if whenever $\chi_1$… $\chi_{m}=y_1$…$y_n$ with each $\chi_{i},y_j \in R$ irreducible, then m = n. In this paper, we show that if R[X] is an HFD, then $Cl_{t}(R)$ $\cong$ $Cl_{t}$(R[X]), and if $G_1$ and $G_2$ are torsion abelian groups, then there exists a Dedekind HFD R such that Cl(R) = $G_1\bigoplus\; G_2$.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.245-251
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• 2007

This study was conducted to investigate the effects of modification of a herbal recipe(Herb $Mix^{(R)}$) on the growth of pullet and laying performance of hens. The formula of Herb $Mix^{(R)}$, a mixture of Rehmannia glutinosa, Angelica gigas, Discorea japonica, Glycyrrhiza uralensis, Schisandra chinensis and Ligusticum jeholense, was modified in mixing ratio. A total of 1,120 pullets(Hy-Line Brown) of 14 wks old were assigned to seven treatments; control, Herb $Mix^{(R)}$(HM), R. glutinosa fortified HM, A. gigas fortified HM, D. japonica fortified HM, G. uralensis fortified HM, S. chinensis fortified HM, L. jeholense fortified HM and Flavomycin supplemented diet. Each treatment had 8 replicates of 20 birds each housed in 2 birds cages. Body weight at 10% egg production was significantly(P<0.05) influenced by treatments. Birds fed A. gigas fortified HM diet were heaviest followed by L. jeholense fortified HM, HM-original and D. japonica fortified HM, Flavomycin supplemented diet and R. glutinosa while those fed control diet were lightest. Also, age reaching 50% egg production and peak production was earliest in A. gigas fortified HM and latest in the control. Egg production, feed intake, feed conversion and egg weight were significantly influenced by treatments. Significant improvement in egg production and feed intake was shown in A. gigas fortified HM treatment. Feed conversion ratio was lowest in antibiotic(Flavomycin) treatment and egg weight was heaviest in L. jeholense fortified HM treatment. There were no significant differences among treatments in intestinal microflora but cfu of Cl. perfringnes and E. coli tended to be lower in HM treatments than the control. Among the leucocytes of blood, the HM treatments were lower than the control in counts of white blood cell and heterophils. It was concluded that modification of Herb $Mix^{(R)}$ fortifying with A. gigas, D. japonica and L. jeholense significantly influence growth and laying performance of birds.

• Bulletin of the Korean Mathematical Society
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• v.55 no.1
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• pp.311-317
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• 2018

Let (R, m) be a commutative Noetherian local ring and I be an ideal of R. In this paper it is shown that if cd(I, R) = t > 0 and the R-module $Hom_R(R/I,H^t_I(R))$ is finitely generated, then $$t={\sup}\{{\dim}{\widehat{\hat{R}_p}}/Q:p{\in}V(I{\hat{R}}),\;Q{\in}mAss{_{\widehat{\hat{R}_p}}}{\widehat{\hat{R}_p}}\;and\;p{\widehat{\hat{R}_p}}=Rad(I{\wideha{\hat{R}_p}}=Q)\}$$. Moreover, some other results concerning the cohomological dimension of ideals with respect to the rings extension $R{\subset}R[X]$ will be included.