• Korean Journal of Mathematics
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• 제4권1호
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• pp.45-49
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• 1996

Let $F_0$ be the maximal real subfield of $\mathbb{Q}({\zeta}_q+{\zeta}_q^{-1})$ and $F_{\infty}={\cup}_{n{\geq}0}F_n$ be its basic $\mathbb{Z}_p$-extension. Let $A_n$ be the Sylow $p$-subgroup of the ideal class group of $F_n$. The aim of this paper is to examine the injectivity of the natural $mapA_n{\rightarrow}A_m$ induced by the inclusion $F_n{\rightarrow}F_m$ when $m>n{\geq}0$. By using cyclotomic units of $F_n$ and by applying cohomology theory, one gets the following result: If $p$ does not divide the order of $A_1$, then $A_n{\rightarrow}A_m$ is injective for all $m>n{\geq}0$.

• 한국도서관정보학회지
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• 제22권
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• pp.327-349
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• 1995

In comparing with the role, scope, and description method of edition statement between monograph and old traditional books, There are some problems solving as follows : 1) Kind of issue offering information on variant imprint must be distinguished from edition merely identifying the newest thing among same materials in the edition area of old traditional books. 2) because of a rule that edition statement follow title statement according to ISBD, could not make a most of the characteristics of old traditional books. As a result of a n.0, pplication MARC format for solving above the problems, the followings have been identified. 1) Subfield in the 245tag can be made a distinction between kind of issue and edition with when describing edition statement of old traditional books. 2) As defining newly the Fixed-Length Data Elements of Marc format, not only basic index terms, such as author, title, etc., but also edition statement on variant kind of issue will be able to provide with restrict index terms.

• Journal of Information Display
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• 제4권4호
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• pp.8-12
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• 2003

In this paper, we report relatively simple equalizing pulse method for reducing dynamic false contour in PDP. Calculation cost is reduced by limiting pixels to add equalizing pulse and using look-up-table(LUT) for given subfield pattern. Pixels to be modified are determined after comparing selected number of most significant bits(MSB) with those of adjacent pixels. The equalizing pulse amount is determined by consulting LUT, which is for a fixed velocity of 1 pixel/tv field. Even though the suggested scheme does not cover every luminance combination of neighboring pixels, it is expected to work well after appropriate modifications are made according to the velocity.

• 대한수학회지
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• 제44권3호
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• pp.499-509
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• 2007

Let m, n be positive integers or monic polynomials in $\mathbb{F}_q[T]$ with n|m. Let $K_m\;and\;K^+_m$ be the m-th cyclotomic field and its maximal real subfield, respectively. In this paper we define two matrices $D^+_{m,n}\;and\;D^-_{m,n}$ whose determinants give us the ratios $\frac{h(\mathcal{O}_{K^+_m})}{h(\mathcal{O}_{K^+_n})}$ and $\frac{h-(\mathcal{O}_K_m)}{h-(\mathcal{O}_K_n)}$ with some factors, respectively.

• Korean Journal of Mathematics
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• 제18권2호
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• pp.161-166
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• 2010

For an abelian extension K of ${\mathbb{Q}}$, let $C_W(K)$ be the group of Washington units of K, and $C_S(K)$ the group of Sinnott units of K. A lot of results about $C_S(K)$ have been found while very few is known about $C_W(K)$. This is mainly because elements in $C_S(K)$ are more explicitly defined than those in $C_W(K)$. The aim of this paper is to find a basis of $C_W(K)$ and use it to compare $C_W(K)$ and $C_S(K)$ when K is a subfield of ${\mathbb{Q}}({\zeta}_{p^e})$, where p is a prime.

• 정보관리학회지
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• 제23권2호
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• pp.21-37
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• 2006

학문의 지식체계를 형성하는데 있어서 하나의 일련과정으로 밀접하게 상호연관된 이론개발 및 이론활용 연구가 뒷받침되어야 한다는 전제 하에, 본 연구는 문헌정보학 연구논문의 이론개발 및 이론활용 사례의 양적/질적 측면을 조사함으로써 문헌정보학의 이론적 기반을 분석하고자 하였다. 특히, 본 연구는 세부주제영역에 따른 이론개발 및 이론활용 연구의 특성에 주목함으로써 문헌정보학의 이론적 기반 형성에 기여한 세부주제영역을 보다 구체적으로 파악하고자 하였다. 이를 위해 1984년부터 2003년에 출판된 1,661편의 연구논문을 대상으로 내용분석을 실시하였다. 분석결과, 22개의 세부주제영역 중에서 정보이용탐색, 정보검색, 도서관경영, 학술커뮤니케이션 영역이 이론개발과 이론활용의 모든 측면에 가장 큰 기여를 한것으로 나타났다. 또한 주제영역별로 생산된 논문 수에 따른 이론적 연구의 비율을 살펴보았을 때, 계량정보학과 전문직 영역에 대한 연구가 매우 이론적인 특성을 보였다. 이 외에 각 세부주제영역별로 사용된 이론을 분석하였을 때, 일부 세부주제영역 간에 유사한 이론적 기반을 공유하고 있는 것으로 나타났다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.1-11
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• 1998

Ameliorating mechanisms of red ginseng on learning deficits were investigated in the following 3 experiments; its effects on 1) place learning deficits in aged rats and in young rats with selective hippocampal lesions (behavioral study), 2) long-term potentiation in the hippocampal formation (neuro- physiological study), and 3) ChAT (choline acetyl transferase) activity in various brain regions of aged rats (pharmacological study). In the behavioral study, first, performance in the place learning tasks were compared among 3 groups of young and aged rats; control young intact rats (10-12 week old) treated with water, aged rats (28-32 month old) treated with water, and aged rats (28-32 month old) treated with red ginseng (100 mghglday) suspended in water. Second, performance in the place learning tasks was compared among 3 groups of young rats; control intact rats treated with water, rats with bilateral hippocampal lesions treated with water, and rats with bilateral hippocampal lesions treated with red ginseng (100 mg/kg/day). Each rat in these 2 behavioral experiments was tested with the 3 types of the place learning tasks in a circular open field using intracranial self-stimulation (ICSS) as reward. The ICSS reward was delivered if the rat (1) moved distance of 100-160 cm (DMT): (2) entered an experiment-determined reward place within the open field, and this place was randomly varied in sequential trials (RRPST); or (3) entered 2 specific places, and did a shuttle behavior between the 2 places (PLT). Performance of the aged rats in the ginseng group was not significantly different from that of control young rats in ICSS (current intensity, bar press rates), DMT and RRPST. However, treatment with red ginseng significantly ameliorated place-navigation learning deficits in aged rats in the PLT. Similarly, red ginseng ameliorated learning and memory deficits in young rats with hippocampal lesions in the same tasks. In the neurophysiological study using young rats, perfusion of hippocampal slices with non-sapon in fraction of red ginseng significantly enhanced magnitudes of the long-term potentiation (LfP) in the CA3 subfield. In the pharmacological study, treatment with red ginseng did not affect ChAT activity in aged rat brain including the hippocampal formation. These results strongly suggest that red ginseng ameliorates learning and memory deficits in aged rats through actions on the CA3 subfield of the hippocampal formation, which were independent of the presynaptic components of the cholinergic system

• 한국도서관정보학회지
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• 제52권1호
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• pp.109-128
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• 2021

본고에서는 LRM 노멘 개체를 수용하기 위한 전거제어시 고려사항을 모색하고자 문헌연구, RDA 규칙분석, 국내 목록 전문가 의견조사를 실시하였다. 그 결과 전거제어를 위해 노멘의 속성 요소, 목록기술, MARC 전거포맷 측면에서 고려사항을 제안하였다. 첫째, 노멘의 속성으로 LRM 노멘의 유형, 스킴, 이용대상자, 이용맥락, 참고정보원, 언어, 문자, 문자변환과 RDA에서 추가한 식별상태, 주기, 구분불가한 이름지시자의 기술을 가능한 상세히 기술해야 한다. 둘째, 노멘의 속성요소 및 관계요소를 기술하기 위해 목록규칙인 RDA에 제시된 대로 비구조화, 구조화, 식별자, IRI로 기술하며, 이중 구조화된 기술을 위해서는 어휘인코딩스킴(VES), 스트링인코딩스킴(SES)이 작성되어야 한다. 또한, 전거형접근점에 대한 구조 및 우선 이름/표제에 대한 목록 규칙도 마련되어야 한다. 셋째, LRM 노멘을 반영할 수 있도록 MARC 21 전거포맷을 마련하기 위해 Maxwell의 확장(안)을 바탕으로 추가 확장 방안을 제안하였다. (1) 노멘 마다 속성이 입력될 수 있도록 4XX, 5XX에 속성이 기술되어야 하며, 1XX, 5XX와 4XX에 기술될 노멘의 속성을 구분하였다. (2) 노멘 속성으로 유형, 언어, 문자, 문자변환, 이용맥락, 유효기간을 기술하기 위해서는 MARC 21내에 표시기호 및 식별기호가 추가되어야 한다. 이에 368, 381, 377의 식별기호 확장과 이용맥락과 유효기간을 기술하기 위한 표시기호를 추가할 것을 제안하였다. 본고에서 제안한 LRM 노멘을 위한 전거제어시 고려사항은 국내에서 LRM을 반영한 전거제어 방안을 마련하는 기반이 될 것이다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.53-60
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• 2002

Motion of lung tumors from respiration has been reported in the literature to be as large as of 1-2 cm. This motion requires an additional margin between the Clinical Target Volume (CTV) and the Planning Target Volume (PTV). While such a margin is necessary, it may not be sufficient to ensure proper delivery of Intensity Modulated Radiotherapy (IMRT) to the CTV during the simultaneous movement of the DMLC. Gated treatment has been proposed to improve normal tissues sparing as well as to ensure accurate dose coverage of the tumor volume. The following questions have not been addressed in the literature: a) what is the dose error to a target volume without gated IMRT treatment\ulcorner b) what is an acceptable gating window for such treatment. In this study, we address these questions by proposing a novel technique for calculating the 3D dose error that would result if a lung IMRT plan were delivered without gating. The method is also generalized for gated treatment with an arbitrary triggering window. IMRT plans for three patients with lung tumor were studied. The treatment plans were generated with HELIOS for delivery with 6 MV on a CL2100 Varian linear accelerator with a 26 pair MLC. A CTV to PTV margin of 1 cm was used. An IMRT planning system searches for an optimized fluence map ${\Phi}$ (x,y) for each port, which is then converted into a dynamic MLC file (DMLC). The DMLC file contains information about MLC subfield shapes and the fractional Monitor Units (MUs) to be delivered for each subfield. With a lung tumor, a CTV that executes a quasi periodic motion z(t) does not receive ${\Phi}$ (x,y), but rather an Effective Incident Fluence EIF(x,y). We numerically evaluate the EIF(x,y) from a given DMLC file by a coordinate transformation to the Target's Eye View (TEV). In the TEV coordinate system, the CTV itself is stationary, and the MLC is seen to execute a motion -z(t) that is superimposed on the DMLC motion. The resulting EIF(x,y)is inputted back into the dose calculation engine to estimate the 3D dose to a moving CTV. In this study, we model respiratory motion as a sinusoidal function with an amplitude of 10 mm in the superior-inferior direction, a period of 5 seconds, and an initial phase of zero.

• Korean Journal of Mathematics
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• 제6권2호
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• pp.221-229
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• 1998

Let $k$ be a real abelian field and $k_{\infty}$ be its $\mathbb{Z}_p$-extension for an odd prime $p$. Let $A_n$ be the Sylow $p$-subgroup of the ideal class group of $k_n$, the $nth$ layer of the $\mathbb{Z}_p$-extension. By using the main conjecture of Iwasawa theory, we have the following: If $p$ does not divide $\prod_{{{\chi}{\in}\hat{\Delta}_k},{\chi}{\neq}1}B_{1,{\chi}{\omega}^{-1}$, then $A_n$ = {0} for all $n{\geq}0$, where ${\Delta}_k=Gal(k/\mathbb{Q})$ and ${\omega}$ is the Teichm$\ddot{u}$ller character for $p$. The converse of this statement does not hold in general. However, we have the following when $k$ is of prime conductor $q$: Let $q$ be an odd prime different from $p$. and let $k$ be a real subfield of $\mathbb{Q}({\zeta}_q)$. If $p{\mid}{\prod}_{{\chi}{\in}\hat{\Delta}_{k,p},{\chi}{\neq}1}B_{1,{\chi}{\omega}}-1$, then $A_n{\neq}\{0\}$ for all $n{\geq}1$, where ${\Delta}_{k,p}$ is the $Gal(k_{(p)}/\mathbb{Q})$ and $k_{(p)}$ is the decomposition field of $k$ for $p$.