• 대한한의학회지
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• 제20권3호
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• pp.54-65
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• 1999

Objectives: Hepatoma is a very serious disease in Korea and vvorldwiclc. Hepatitis B vims (HBV) has proved the most significant cause of hepatoma. We canied out this study to investigate the effect of Acanthopanax sessilifloms on inhibiting cell proliferation and DNA synthesis in HepG2.2.15 cell line and on inhibiting phosphorilation of oncogene (MAP kinase) in NIT/3T3-HBx ceIl. Methods: To investigate the anti-cancer effect of Acanthopanax sessiliflorus, we did the CellTiter 96 Aqueous Non-radioactive Cell Proliferation assay (Promega); MTS/PMS assay, [$^3H$]-thymicline incorporation assay, and we measured the gene expression through westem blotting. Results: Acanthopanax sessiliflorus showed an inhibiting effect on the increase of HepG2.2.15 in the NTS/PMS assay. It also showed an inhibiting effect on DNA synthesis of HepG2.2.15 in the [$^3H$]-thymidine incorporation assay. Acanthopanax sessiliflorus showed an inhibiting effect of phosphorilation of MAP kinase in HBV - X genes. too. Conclusions: The results suggested that this herb had an anti cancer effect. We may discover an effective anti-cancer herb medicine through further studies on this herb medicine.

• 대한수학회지
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• 제56권5호
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• pp.1355-1370
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• 2019

A curve $X{\subset}\mathbb{P}^r$ has maximal rank if for each $t{\in}\mathbb{N}$ the restriction map $H^0(\mathcal{O}_{\mathbb{P}r}(t)){\rightarrow}H^0(\mathcal{O}_X(t))$ is either injective or surjective. We show that for all integers $d{\geq}r+1$ there are maximal rank, but not arithmetically Cohen-Macaulay, smooth curves $X{\subset}\mathbb{P}^r$ with degree d and genus roughly $d^2/2r$, contrary to the case r = 3, where it was proved that their genus growths at most like $d^{3/2}$ (A. Dolcetti). Nevertheless there is a sector of large genera g, roughly between $d^2/(2r+2)$ and $d^2/2r$, where we prove the existence of smooth curves (even aCM ones) with degree d and genus g, but the only integral and non-degenerate maximal rank curves with degree d and arithmetic genus g are the aCM ones. For some (d, g, r) with high g we prove the existence of reducible non-degenerate maximal rank and non aCM curves $X{\subset}\mathbb{P}^r$ with degree d and arithmetic genus g, while (d, g, r) is not realized by non-degenerate maximal rank and non aCM integral curves.

• IMMUNE NETWORK
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• 제2권2호
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• pp.72-78
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• 2002

Background: The precise mechanism by which CTLA-4 regulates T cell immune responses is still not fully understood. Previously we proposed that CTLA-4 could downregulate T cell function by modulating a signaling cascade initiated from the T cell receptor complex. The evidence for this notion comes from our findings that CTLA-4 associated with the T cell receptor zeta (TCR zeta) chain, and hence regulated TCR zeta phosphorylation by co-associated SHP-2 tyrosine phosphatase (1). In this report, we investigated whether any other signaling molecules could be involved in the CTLA-4 signaling pathway. Methods: We have taken biochemical approaches, such as immunoprecipitation followed by autoradiography or immunoblotting, to identify the molecules associated with CTLA-4. To perform these assays, we used activated primary T cells and ectopically transfected 293 cells. Various truncation mutants of CTLA-4 were used to map the interaction site on CTLA-4. Results: We found that in addition to TCR zeta and SHP-2, a recently cloned small adaptor molecule, SAP (SLAM-associated protein), was also able to associate with CTLA-4. We identified the domain of SAP association in CTLA-4 being a motif involving GVYVKM. This motif has been previously found to bind SHP-2 through its phosphorylated tyrosine interaction with SH-2 domain of SHP-2. Indeed, co-expression of SAP and SHP-2 reduced their binding to CTLA-4 significantly, suggesting that SAP and SHP-2 compete for the common binding site, GVYVKM. Thus, by blocking SHP-2 recruitment SAP could function as a negative regulator of CTLA-4. Conclusion: Taken together, our data suggest the existence of complicate signaling cascade in regulating CTLA-4 function, and further provide evidence that SAP can act either as a positive or negative regulator depending on the nature of the associating receptors.

• Investigative Magnetic Resonance Imaging
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• 제15권2호
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• pp.154-159
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• 2011

고환 표피 낭종은 드문 양성 종양으로, 모든 고환 종양의 1-2%를 차지한다. 양성 질환으로 고환의 보존이 가능하므로 수술 전에 정확한 진단이 가능하다면 불필요한 고환 절제술을 피할 수 있다. 저자는 오른쪽 음낭의 무통성 종괴로 내원한 18세 남자의 고환 표피 낭종 한 례를 경험하여 보고하고자 한다. 종괴는 초음파상 양파환 징후를 보였고 컴퓨터 단층 촬영에서는 종괴 내부에 곡선의 석회화가 관찰되었다. 자기공명영상 T2 강조영상에서 종괴는 내부에 교차하는 저 신호의 환을 동반하는 고신호 강도로 보였다. 확산강조 영상에서 이 종괴는 고신호 강도를 보이고 현상확산계수(ADC) 영상에서는 낮은 값을 보였으며 이와 같은 소견은 두개내 표피 낭종에서 보고된 바와 동일한 것이다. 기존의 자기공명영상에 확산강조 영상과 현상확산계수 영상을 추가로 시행한다면 고환 표피 낭종의 진단에 도움이 될 것으로 기대된다.

• 대한수학회보
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• 제38권4호
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• pp.657-662
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• 2001

It is proved that if for each n, $1\leqp_n\leq2 \;and \;the(p_n, p’_n)$ Clarkson inequality holds in each Banach space X$_{n}$ then the (t, t’) Clarkson inequality holds in ($\sum^\infty_{n=1}\; X_n)_r, \;the \ell^r-sum \;of\; X_n’s,\; where\; 1\leqr<\infty,\; t=min{p, r, r’} \;and \;p = \;inf{p_n}.$ The (p, p’) Clarkson inequality is preserved by quotient maps and a new proof of a Takahashi-Kato theorem stating that the (p, p’) Clarkson inequality holds in a Banach space X if and only if it holds in its dual space $X_*$ is given.n.

• 대한전기학회논문지:전력기술부문A
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• 제51권4호
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• pp.202-208
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• 2002

In a dynamic game where the players move in a periodical sequence, each player observes the strategy of the others. So the players who move later in a game get to know the moves of others having made before them. Those who move earlier must take this into account in devising their optimal strategy. In the Poolco model, the bidding game is executed periodically. The player participating in the bidding game accumulates the information of its own and others'strategies, and payoffs through the repeated bidding process. Thereby, the players in this game would be able to map out how get the maximum profit, and get closer to the optimal strategy. This paper presents a mathematical modeling for a player to determine his or her optimal strategy at period T, based on the information acquired from the previous rounds for the periods, T-1, T-2, and so on. The proposed modeling is demonstrated with a dynamic fame theory.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.63-66
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• 2001

In the Poolco model, the bidding game is executed periodically. The player participating to the bidding game accumulates the information of others' strategies and payoffs through the repeated process. Thereby, he is able to map out how he gets his maximum profit, and proceed to the optimal strategy region. This paper shows the algorithm for a player to determine his strategy in t period based the information of the game results of t-1, t-2 period. And this algorithm can be formulated by using Dynamic game theory.

• Journal of Applied and Pure Mathematics
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• 제4권1_2호
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• pp.1-7
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• 2022

A mapping T : R → R (not necessarily additive) is called multiplicative left 𝛼-centralizer if T(xy) = T(x)𝛼(y) for all x, y ∈ R. A mapping F : R → R (not necessarily additive) is called multiplicative (generalized)(𝛼, 𝛽)-derivation if there exists a map (neither necessarily additive nor derivation) f : R → R such that F(xy) = F(x)𝛼(y) + 𝛽(x)f(y) for all x, y ∈ R, where 𝛼 and 𝛽 are automorphisms on R. The main purpose of this paper is to study some algebraic identities with multiplicative (generalized) (𝛼, 𝛽)-derivations and multiplicative left 𝛼-centralizer on the left ideal of a prime ring R.

• 대한의용생체공학회:의공학회지
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• 제32권3호
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• pp.245-250
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• 2011

Parallel imaging technique can provide several advantages for a multitude of MRI applications. Especially, in SENSE technique, sensitivity maps were always required in order to determine the reconstruction matrix, therefore, a number of difference approaches using sensitivity information from coils have been demonstrated to improve of image quality. Moreover, many filtering methods were proposed such as adaptive matched filter and nonlinear diffusion technique to optimize the suppression of background noise and to improve of image quality. In this study, we performed SENSE reconstruction using computer simulations to confirm the most suitable method for the feasibility of filtering effect and according to changing order of polynomial fit that were applied on variation of spatial resolution of sensitivity map. The image was obtained at 0.32T(Magfinder II, Genpia, Korea) MRI system using spin-echo pulse sequence(TR/TE = 500/20 ms, FOV = 300 mm, matrix = $128{\times}128$, thickness = 8 mm). For the simulation, obtained image was multiplied with four linear-array coil sensitivities which were formed of 2D-gaussian distribution and the image was complex white gaussian noise was added. Image processing was separated to apply two methods which were polynomial fitting and filtering according to spatial resolution of sensitivity map and each coil image was subsampled corresponding to reduction factor(r-factor) of 2 and 4. The results were compared to mean value of geomety factor(g-factor) and artifact power(AP) according to r-factor 2 and 4. Our results were represented while changing of spatial resolution of sensitivity map and r-factor, polynomial fit methods were represented the better results compared with general filtering methods. Although our result had limitation of computer simulation study instead of applying to experiment and coil geometric array such as linear, our method may be useful for determination of optimal sensitivity map in a linear coil array.

• 한국측량학회지
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• 제19권2호
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• pp.173-181
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• 2001

수치지도 일반화 과정을 통해 생성된 수치지도의 공간데이터에 관한 품질을 평가하는 것은 매우 중요하다. 본 연구에서는, 공간데이터 품질유지 측면에서, 변환된 수치지도 데이터가 해당 축척의 수치지도 규정 및 정확도에 위배되지 않도록 하기 위해 이론적 기대정확도의 허용범위를 살펴보고 공간데이터의 품질 평가 기준을 정립하였다. 그리고, 대축척 수치지도를 소축척 수치지도로 변환할 때, 단순화, 완만화, 정리 등과 같은 처리과정을 통해 복잡성을 감소시키게 되면 공간적인 위치변화는 항상 발생하게 될 것이다. 따라서, 각 지점의 변환된 위치에 관한 공간정확도를 분석하는 것은 매우 힘든 일이기 때문에 평가방법으로서 버퍼링기법을 이용하였다. 비록 축척 1/1,000 및 l/5,000에 대한 일반적인 위치오차의 허용범위는 관련법규를 기준으로 결정되었다 하더라도, 각 처리요소에 적용된 알고리즘들은 서로 다른 특성을 가지고 있기 때문에, 알고리즘에 따라 적절한 매개변수와 허용오차를 결정하지 않는다면, 일반화 처리후의 허용범위를 만족할 수 없을 것이다. 허용범위에 근거를 둔 각 알고리즘의 변수에 관한 본 연구에서의 실험결과는 단순화 및 위치오차의 매개변수가 각각 0.2617 m, 0.4617 m를 나타내고 있었다.