• 대한수학회논문집
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• 제9권4호
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• pp.831-836
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• 1994

In this paper we characterize the quasiaffine transforms of quasisubscalar operators. Let H and K be separable, complex Hilbert spaces and L(H,K) denote the space of all linear, bounded operators from H to K. If H = K, we write L(H) in place of L(H,K). A linear bounded operators S on H is called scalar of order m if there is a continuous unital morphism of topological algebras $$ \Phi : C^m_0(C) \to L(H) $$ such that $\Phi(z) = S$, where as usual z stands for identity function on C, and $C^m_0(C)$ stands for the space of compactly supproted functions on C, continuously differentiable of order m, $0 \leq m \leq \infty$.

• 천문학회지
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• 제44권5호
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• pp.195-200
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• 2011

We have revisited the ACS Virgo Cluster Survey (ACSVCS), a Hubble Space Telescope program to obtain ACS/WFC g and z bands imaging for a sample of 100 early-type galaxies in the Virgo Cluster. In this study, we examine 51 nucleated early-type galaxies in the ACSVCS in order to look into the relationship between the photometric and structural properties of stellar nuclei and their host galaxies. We morphologically dissect galaxies into five classes. We note that (1) the stellar nuclei of dwarf early-type galaxies (dS0, dE, and dE,N) are generally fainter and bluer with g > 18.95 and (g-z) < 1.40 compared to some brighter and redder counterparts of the ellipticals (E) and lenticular galaxies (S0), (2) the g-band half-light radii of stellar nuclei of all dwarf early-type galaxies (dS0, dE, and dE,N) are smaller than 20 pc and their average is about 4 pc, and (3) the colors of red stellar nuclei with (g - z) > 1.40 in bright ellipticals and lenticular galaxies are bluer than their host galaxies colors. We also show that most of the unusually "red" stellar nuclei with (g-z) > 1.54 in the ACSVCS are the central parts of bright ellipticals and lenticular galaxies. Furthermore, we present multi photometric band color - color plots that can be used to break the age-metallicity degeneracy particularly by inclusion of the thermally pulsing-asymptotic giant branch (TP-AGB) phases of stellar evolution in the stellar population models.

• 상하수도학회지
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• 제20권1호
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• pp.63-70
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• 2006

Biosorption characteristics were investigated at various temperature and pH conditions in order to establish lead(II) removal using Zoogloea ramigera 115SLR. Biosorption equilibrium isotherms and kinetics were obtained from batch experiments. The Freundlich and Langmuir model could be described the biosorption equilibrium of lead(II) on Z. ramigera 115SLR, Ca-alginate bead and immobilized Z. ramigera 115SLR. The maximum biosorption capacity of Z. ramigera 115SLR increased from 325 to 617mg $pb^{2+}/g$ biomass as temperature increased from 288.15 K to 308.15K from the Langmuir model. Fixed-bed column breakthrough curves for lead(II) removal were also obtained. For regeneration of the biosorbent, complete lead(II) desorption was achieved using 5mM HCl in fixed-bed column. This study shows the possibilities that well-treated immobilized Z. ramigera 115SLR with the mechanical intensity like TEOS (Tetraethyl orthosilicate) treatment and the optimum acid solution for desorption can be used for the effective treatment for lead(II) containing wastewater.

• 한국멀티미디어학회논문지
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• 제23권3호
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• pp.421-429
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• 2020

Recently, with the development of IoT technology and the increase of energy consumption, interest in energy saving and energy efficiency improvement is rapidly increasing. In particular, in the case of a device connected to a power plug with the power shutoff, a problem with standby power has been raised. Thus technology development through a low power method such as Zigbee is in progress. However, Zigbee, which is generally used, has a problem that a separate gateway is required because it is not an IP-based technology, and there is a problem that it is not suitable for a traditional computer network to which a variety of devices are connected. Therefore, in this paper, we designed and implemented a standby power saving system using MQTT, an IoT standard protocol, in Z-Wave environment. In order to evaluate the implemented standby power saving system, the same environment as the existing Zigbee-based standby power saving system was compared and evaluated.

• 한국전산유체공학회지
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• 제6권1호
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• pp.21-30
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• 2001

A numerical study on the similarity of the developing laminar flows between in a straight duct rotating about an axis perpendicular to that of the duct and in a stationary curved duct was carried out. In order to clarify the analogy of two flows, dimensionless parameters K/sub LR/ = Re/(equation omitted) and Rossby number, Ro, in a rotating straight duct were used as a set corresponding to Dean number K/sub LC/ = Re/(equation omitted), and curvature ratio, λ, in a stationary curved duct. For the large values of Ro and λ, it is shown that the flow field satisfies the 'asymptotic invariance property', that is, there are strong quantitative similarities between the two flows such as flow patterns, friction factors, and maximum axial velocity magnitudes for the same values of K/sub LR/ and K/sub LC/ if they are correlated with dimensionless axial distances Z/sub R/ = z/(equation omitted) for a rotating duct flow and Z/sub C/ = z/(equation omitted) for a stationary curved duct flow.

• 정보관리학회지
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• 제14권1호
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• pp.47-76
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• 1997

본 논문에서는 네트워크를 통한 전자도서관 구축을 활성화하며 도서관 정보자원의 공동 활용을 증진시키기 위해 OSI표준인 정보검색 프로토콜과 도서관 상호대차 프로토콜의 구현 방안을 제시하고 있다. 정보검색 응용 프로토콜로는 미국의 표준인 Z39.50과 ISO 표준인 SR에 관해 그 기능과 구현사례를 중심으로 살펴보고, 도서관 상호대차 응용 프로토콜로는 ISO표준인 ILL프로토콜과 Z39.50의 자료주문 확장서비스에 관해 살펴보았다. 도서관 자동화 패키지 시스템 판매업체나 각 도서관은 정보검색 표준 프로토콜을 구현한 OPAC시스템을 개발함으로써 국내외 타 도서관의 온라인 목록을 손쉽게 탐색할 수 있도록 하며, 이와 함께 도서관 상호대차 표준 프로토콜을 구현한 상호대차 시스템을 구축함으로써 온라인 목록 탐색과 원문 주문/전달기능을 통합하여 탐색후 즉각적인 원문주문과 전달이 가능하도록 해야 할 것이다.

• 정보관리학회지
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• 제17권1호
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• pp.129-148
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• 2000

최근 구축된 한글 실험문헌 집단을 대상으로 2-포아송 모형의 Z값의 주제어 식별력을 측정하였으며, 역문헌빈도와 2 포아송 모형간의 상관관계를 분석하였다. 이를 위해 Z와 수정 $\beta$값 및 IDF와 수정 TF.IDF 가중치를 하위 실험집단별로 각기 산출, 비교하였다. 실험 결과 Z값의 주제어 선정능력은 3개의 하위 실험집단 가운데 과학기술분야에서만 확인되었다. 2-포아송 모형의 Z값과 역문헌빈도 가중치간의 상관관계 분석에서는 전문(full text)인 여성학분야 실험집단에 비해 초록 및 신문기사와 같이 단문(short text)으로 구성된 과학기술분야 및 일반사회 분야 실험집단에서 상관관계가 더 크게 나타 났다.

• Journal of Power Electronics
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• 제12권4호
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• pp.623-631
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• 2012

In this paper, a digital controller design procedure is presented for single-phase voltage-doubler boost rectifiers (VDBR). The model derivation of the single-phase VDBR is performed in the s-domain. After that the simplified equivalent z-domain models are derived. These z-domain models are utilized to design the input current and the output dc-link voltage controllers. For the controller design in the z-domain, the traditional K-factor method is modified by considering the nature of the digital controller. The frequency pre-warping and anti-windup techniques are adapted for the controller design. By using the proposed method, the phase margin and the control bandwidth are accurately achieved as required by controller designers in a practical frequency range. The proposed method is applied to a 2.5 kVA single-phase VDBR for Uninterruptible Power Supply (UPS) applications. From the simulation and the experimental results, the effectiveness of the proposed design method has been verified.

• 생약학회지
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• 제26권4호
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• pp.368-376
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• 1995

The leaf of Phyllostachys bambusoides S. et Z. (Gramineae) has been used in traditional herbal medicine as a antipyretics, antitussives and antidiuretcs, etc, in Korea, China and Japan. In order to investigate the effects on antilipoperoxidation and liver protective effect, the leaf of Phyllostachys bambusoides S. et Z. was extracted by water and then fractionated with butanol. The water extract and BuOH soluble fraction strongly exhibited antilipoperoxidatant effect in rat liver homogenate intoxicated with $CCl_4$. The BuOH fraction significantly suppressed the increases of s-GOT, s-GPT and s-LDH activities in injuried rats induced by $CCl_4$. And the BuOH fraction inhibited significantly the decrease of the body weight and showed the antilipoperoxidatant effect in liver and kidney in $CCl_4$ intoxicated rats.

• 한국생산제조학회지
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• 제20권3호
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• pp.357-360
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• 2011

Machine tools of Gantry type have been performing machine work as a moving machinery. In a large machine tools, the machinery is moving with bed and it is structurally unstable. When the objects are processed, machine tools gets loads in the direction of Z-axis. In other words, the machine tools which become bigger was performed by the trend of complexation. It made that the increased machine weight can't be passed over. In order to enhance manufacturing precision, it needs to compensate Z-axis deflection of weight for machine tools. In this paper, Machine tools of Gantry type were miniaturized and deflection was measured by LVDT sensors. When deflection was measured, block mass weighted 50kg is moving on particular distance. Then, the displacement of fixed point and moving point is measured by recording telemeter.