• The Transactions of the Korea Information Processing Society
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• v.5 no.4
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• pp.967-974
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• 1998

Access control scheme of the firewall systems protects the systems from threats by using the conventional discretionary access control mechanism. The discretionary access control mechanism is insufficient to control secure information flow on the multievel network. Thus, it is necessary to provide the mandatory access control mechanism to the firewall systems for the multilevel security environment. In this paper, we present a design scheme of the security mechanisms concerning the sensitivity label and the mandatory access control for securely processing the multilevel information.

• Journal of the Chungcheong Mathematical Society
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• v.20 no.4
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• pp.387-399
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• 2007

In this paper, we prove the generalized Hyers-Ulam stability of the following linear functional equations f(x + iy) + f(x - iy) + f(y + ix) + f(y - ix) = 2f(x) + 2f(y) and f((1 + i)x) = (1 + i)f(x), and of the following quadratic functional equations f(x + iy) + f(x - iy) + f(y + ix) + f(y - ix) = 0 and f((1 + i)x) = 2if(x) in complex Banach spaces.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1117-1120
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• 2005

위치응용 서비스는 유비쿼터스 컴퓨팅의 구현의 기반이 되는 중요 기술요소 중 하나이다. 특히 스마트 홈, 지능형 단말기, 스마트 스페이스의 구현을 위해서는 광역범위보다는 실내환경에서의 사용자, 오브젝트의 위치인식에 대한 연구기술이 필요하다. 본 논문에서는 무선센서 플랫폼 및 통신기술을 이용한 실내 위치인식 시스템의 설계 및 구현에 관해 기술하고자 한다. 사용자 위치인식을 위한 기반기술로 RF 무선신호와 초음파신호간의 속도차를 이용한 DTOF 기반 거리측정과 삼각측량 기법을 이용하였다. $3{\sim}10cm$ 의 위치오차를 가지는 정밀 위치계측 기술로, 개발된 시스템은 무선센서 플랫폼과 임베디드 게이트웨이 시스템, 위치계측 서버 시스템으로 구성되며, 시스템의 개발 및 실제환경에서의 테스트를 통하여 실생활 응용에 대한 가능성을 확인할 수 있었다. 또한 오차보정 및 멀티 센서를 통한 위치보정기법에 대해서도 논의한다.

• Journal of Industrial Technology
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• v.17
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• pp.137-143
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• 1997

The objective of this study is to find the strength properties of concrete using blast furnace slag. Its mechanical strength properties investigated include compressive strength, flexural strength, and tensile strength. The main expeirmental variables were cement type, coarse aggregate size(19, 25mm), and water/cement ratio(28, 32, 36%). The principal results obtained from this study are as follows ; it was possible to obtain the compressive strength of $500{\sim}700kg/cm^2$ concrete by using the blast furnace slag. Therefore, blast furnace slag was proved to be superior to ordinary portland cement in manufacturing the high strength concrete with the same mix conditions. In the near furture, concrete using blast furnace slag is expected to be practically used in the field.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.601-604
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• 2006

본 논문에서는 기업에서 관리되고 있는 설비 및 자산을 여러 가지 요인의 재난 위험으로부터 보호하는 것을 목적으로 하여 작업장 감지 시스템 WMS(Workshop Monitoring System)를 개발하였다. 이 시스템은 세 부분으로 구성된다. (1) 작업장 환경 자료를 수집하기 위한 센서 (2) 센서 데이타를 기록하고 SMS 메시지를 발생시키는 Status Logging Server (3) SMS Gateway 등으로 구성된다. 이러한 WMS는 각종 재해 발생시에 치명적인 손실을 초래 할 수 있는 시설들에 대해 즉각적인 조치를 위한 통보 시스템으로 활용할 수 있을 것이다.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.214-217
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• 1990

The voltage of distribution systems is controlled according to the proper rate of voltage drop and the loss constraints etc.. In modern distribution system it is necessary to supply energy according to the priority of reliabilities of the system. This paper proposes an efficient algorithm of the management of distribution systems considering the system reliabilities and gives a more accurate and economic control of the voltage of distribution systems.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.79.1-79.1
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• 2013

We present new integrated spectroscopy of 24 Galactic globular clusters, observed with the Isaac Newton Telescope in La Palma. Spectra have been extracted from one core radius for each cluster, achieving high wavelength resolution of FWHM ${\sim}2.0^{\circ}A$. In combination with two previous data sets from Puzia et al. 2002 and Schiavon et al. 2005, we construct the largest database of the Lick indices for total 53 Galactic globular clusters. The empirical metallicity.index relations are given for the 20 Lick indices for the use of deriving metallicities of remote, unresolved stellar systems.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.196-201
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• 1999

Four antioxidative flavonoids were isolated from the aerial parts of Hypericum erectum. Their structures were identified as quercitrin (I), isoquercitrin (Ⅱ), hyperoside (Ⅲ) and orientin (IV) on the basis of spectroscopic means. Antioxidative activities for flavonoids $I{\sim}IV$ were determined by measuring lipid peroxide using 2-thiobarbituric acid (TBA) method and by evaluation the radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Compound IV, orientin, was found to have strong antioxidative potency.

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.324-325
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• 2011

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.322-323
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• 2011