• Korean Journal of Mathematics
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• v.4 no.1
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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 $m>n{\geq}0$.

• Journal of Korean Library and Information Science Society
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• v.22
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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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• v.4 no.4
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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.

• Journal of the Korean Mathematical Society
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• v.44 no.3
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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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• v.18 no.2
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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.

• Journal of the Korean Society for information Management
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• v.23 no.2
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• pp.21-37
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• 2006

Based upon the assumption that both theory building and theory use are intertwined to construct a cohesive body of knowledge in the filed, this study attempts to identify the state of theoretical framework by examining the number and the quality of theoretical articles by subfield. Theoretical article is characterized as an incident in which in which the author contributes to the development or the use of theory in his/her own paper. Theoretical incidents were identified by a content analysis of 1,661 articles in four LIS journals from 1984 to 2003. The findings suggest that the four subfields, such as information seeking/use, information retrieval, library management, and scholar communication had great contributions to both theory building and theory use. Also, two research areas such as bibliometrics and professionals are very likely to be theoretical. Further, the analysis of the name of theories used by subfields could give an insight into the understanding of how the theoretical frameworks of each subfield are related.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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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

• Journal of Korean Library and Information Science Society
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• v.52 no.1
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• pp.109-128
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• 2021

This paper is to explore considerations in authority control to accommodate LRM nomen entities through the literature reviews, the analysis of RDA rules, and the opinion survey of domestic catalog experts. As a result, for authority control, considerations were proposed in the aspect of nomen's attribute elements, catalog description, and MARC authority format. First, it is necessary to describe in as much detail as possible the category, the scheme, intended audience, the context of use, the reference source, the language, the script, the script conversion as the attributes of the nomen with the status of identification, note, and indifferentiated name indicators added in RDA. Second, the description method of attribute elements and relational elements of nomen can be unstructured, structured, identifier, and IRI as suggested in RDA, and vocabulary encoding scheme (VES) and string encoding scheme (SES) should be written for structured description, Also, cataloging rules for structuring authorized access points and preferred names/title should be established. Third, an additional expansion plan based on Maxwell's expansion (draft) was proposed in order to prepare the MARC 21 authority format to reflect the LRM nomen. (1) The attribute must be described in 4XX and 5XX so that the attribute can be entered for each nomen, and the attributes of the nomen to be described in 1XX, 5XX and 4XX are presented separately. (2) In order to describe the nomen category, language, script, script conversion, context of use, and date of usage as a nomen attribute, field and subfield in MARC 21 must be added. Accordingly, it was proposed to expand the subfield of 368, 381, and 377, and to add fields to describe the context of use and date of usage. The considerations in authority control for the LRM nomen proposed in this paper will be the basis for establishing an authority control plan that reflects LRM in Korea.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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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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• v.6 no.2
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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 $p$.