• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.182-192
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• 2015

In this paper, we introduce how to change the reaction rate as mol concentration when we scan enhanced MRI with GBCA(Gadolinium Based Contrast Agent), Also show the changing patterns depending on diverse MRI sequences which are made by different physical principle. For this study, we made MRI phantom ourselves. We mixed 500 mmol Gadoteridol with Saline in each 28 different containers from 500 to 0 mmol. After that, MR phantom was scanned by physically different MRI sequences which are T1 SE, T2 FLAIR, T1 FLAIR, 3D FLASH, T1 3D SPACE and 3D SPCIR in 1.5T bore. The results were as follows : *T1 Spin echo's Total SI(Signal Intensity) was 15608.7, Max peak was 1352.6 in 1 mmol. *T2 FLAIR's Total SI was 9106.4, Max peak was 0.4 1721.6 in 1 mmol. *T1 FLAIR's Total SI was 20972.5, Max peak was 1604.9 in 1 mmol. *3D FLASH's Total SI was 20924.0, Max peak was 1425.7 in 40 mmol. *3D SPACE 1mm's Total SI was 6399.0, Max peak was 528.3 in 3 mmol. *3D SPACE 5mm's Total SI was 6276.5, Max peak was 514.6 in 2 mmol. *3D SPCIR's Total SI was 1778.8, Max peak was 383.8 in 0.4 mmol. In most sequences, High signal intensity was shown in diluted lower concentration rather than high concentration, And also graph's max peak and pattern had difference value according to the each different sequence. Through this paper which have quantitative result of GBCA's reaction rate depending on sequence, We expect that practical enhanced MR protocol can be performed in clinical field.

• Korean Journal of Mathematics
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• v.8 no.2
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• pp.163-172
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• 2000

Let $\mathcal{S}^{\prime}(\mathbb{R})$ be the dual of the Schwartz spaces $\mathcal{S}(\mathbb{R})$), A be a self-adjoint operator in $L^2(\mathbb{R})$ and ${\Gamma}(A)^*$ be the adjoint operator of ${\Gamma}(A)$ which is the second quantization operator of A. It is proven that under a suitable condition on A there exists a nuclear subspace $\mathcal{S}$ of a fundamental space $\mathcal{S}_A$ of Hida's type on $\mathcal{S}^{\prime}(\mathbb{R})$) such that ${\Gamma}(A)\mathcal{S}{\subset}\mathcal{S}$ and $e^{-t{\Gamma}(A)}\mathcal{S}{\subset}\mathcal{S}$, which enables us to show that a stochastic differential equation: $$dX(t)=dW(t)-{\Gamma}(A)^*X(t)dt$$, arising from the central limit theorem for spatially extended neurons has an unique solution on the dual space $\mathcal{S}^{\prime}$ of $\mathcal{S}$.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.489-492
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• 2007

At COMS SOC, 13m antenna system will serve to transmit command and receive telemetry in S-Band for COMS operation. In addition, Sensor Data and LRIT/HRIT in L-Band will be received and LRIT/HRIT in S-Band will be transmitted through this antenna system. In many cases, G/T is used as barometer to estimate the receiving capability of antenna system. To estimate G/T, this paper presents two approaches, one is analysis based on the specification of antenna and RF equipment while the other is measurement by using Sun. From the results, G/T was proven as more than 20dB/K and it means that the required G/T, 19dB/K is verified successfully.

• Korean Journal of Mathematics
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• v.31 no.4
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• pp.479-484
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• 2023

In this paper, we introduce the concept of a generalized derived set in generalized topological spaces and we investigate its properties. Using these, we study T_D-spaces in generalized topological spaces.

• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.891-908
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• 1996

Let (X,d) be a metric space and let T be a mapping from X into itself. We say that a metric space (X,d) is T-orbitally complete if every Cauchy sequence of the form ${T^{n_i}x}_{i \in N}$ for $x \in X$ converges to a point in X.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.9
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• pp.289-304
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• 2022

It is necessary to apply process algebra and logic in order to analyze and verify safety requirements for Smart IoT Systems due to distributivity and mobility of the systems over some predefined geo-temporal space. However the analysis and verification cannot be fully intuitive over the space due to the fact that the existing process algebra and logic are very limited to express the distributivity and the mobility. In order to overcome the limitations, the paper presents a new logic, namely for GTS-VL (Geo-Temporal Space-Visual Logic), visualization of the analysis and verification over the space. GTS-VL is the first order logic that deals with relations among the different types of blocks over the space, which is the graph that visualizes the system behaviors specified with the existing dTP-Calculus. A tool, called SAVE, was developed over the ADOxx Meta-Modeling Platform in order to demonstrate the feasibility of the approach, and the advantages and practicality of the approach was shown with the comparative analysis of PBC (Producer-Buffer-Consumer) example between the graphical analysis and verification method over the textual method with SAVE tool.

• Journal of the Chungcheong Mathematical Society
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• v.34 no.3
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• pp.259-269
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• 2021

We shall study the following. Let 𝜙 be an expansive flow on a compact TVS-cone metric space (X, d). First, we give some equivalent ways of defining expansiveness. Second, we show that expansiveness is conjugate invariance. Finally, we prove that lim sup ${\frac{1}{t}}$ log v(t) ≤ h(𝜙), where v(t) denotes the number of closed orbits of 𝜙 with a period 𝜏 ∈ [0, t] and h(𝜙) denotes the topological entropy. Remark that in 1972, R. Bowen and P. Walters had proved this three statements for an expansive flow on a compact metric space [?].

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.105-111
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• 2019

Let $Y{\subset}{\mathbb{P}}^3$ be a degree d reduced curve with only planar singularities. We prove that $h^i({\mathcal{I}}_Y(t))=0$, i = 1, 2, for all $t{\geq}d-2$. We use this result and linkage to construct some triples (d, g, s), $d>s^2$, with very large g for which there is a smooth and connected curve of degree d and genus g, $h^0({\mathcal{I}}_C(s))=1$ and describe the Hartshorne-Rao module of C.

• Bulletin of the Korean Mathematical Society
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• v.44 no.4
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• pp.731-742
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• 2007

Let X be a Banach space, $A:D(A){\subset}X{\rightarrow}X$ the generator of a compact $C_0-semigroup\;S(t):X{\rightarrow}X,\;t{\geq}0$, D a locally closed subset in X, and $f:(a,b){\times}C([-q,0];X){\rightarrow}X$ a function of Caratheodory type. The main result of this paper is that a necessary and sufficient condition in order that D be a viable domain of the semi linear differential equation of retarded type $$u#(t)=Au(t)+f(t,u_t),\;t{\in}[t_0,\;t_0+T],{u_t}_0={\phi}{\in}C([-q,0];X)$$ is the tangency condition $$\limits_{h{\downarrow}0}^{lim\;inf\;h^{-1}d(S(h)v(0)+hf(t,v);D)=0}$$ for almost every $t{\in}(a,b)$ and every $v{\in}C([-q,0];X)\;with\;v(0){\in}D$.

• Korean Journal of Mathematics
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• v.31 no.1
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• pp.35-48
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• 2023

Let 𝔼 be a CAT(0) space and K be a nonempty closed convex subset of 𝔼. Let T : K → 𝓟(K) be a multimap such that F(T) ≠ ∅ and ℙ_T(x) = {y ∈ Tx : d(x, y) = d(x, Tx)}. Define sequence {x_n} by x_n+1 = (1 - α)𝜈_n⊕αw_n, y_n = (1 - β)u_n⊕βw_n, z_n = (1-γ)x_n⊕γu_n where α, β, γ ∈ [0; 1]; u_n ∈ ℙ_T (x_n); 𝜈_n ∈ ℙ_T (y_n) and w_n ∈ ℙ_T (z_n). (1) If ℙ_T is quasi-nonexpansive, then it is proved that {x_n} converges strongly to a fixed point of T. (2) If a multimap T satisfies Condition(I) and ℙ_T is quasi-nonexpansive, then {x_n} converges strongly to a fixed point of T. (3) Finally, we establish a weak convergence result. Our results extend and unify some of the related results in the literature.