• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.316-317
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• 1997

For successful endodontic therapy, complete and accurate biochemical and chemical preparations will allow accurate root canal. Hence the accurate determination of root length is very important for the highest rates of success in endodontic therapy. Among the apex locators, frequency dependent type has higher accuracy and more advantages than others. In this paper, we proposed better frequencies for the method of measuring root canal length by the ratio of two different impedances. It was found that 500Hz and 10kHz is better selection than other frequencies used in the commercial products.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.59-63
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• 2000

For the Mo-tip field emitter array, the method by which the geometrical structure of the gate insulator wall could be modified in order to improve field emission properties(turn-on voltage and gate leakage current). The device having a gate insulator of complex shape, which means the combined geometrical structure with round shape made by wet etching and vertical shape made by dry etching processes, was fabricated and the field emission properties of the three kinds of devices were compared. As a result, the electric field applied to tip apex could be increased and gate leakage current could be decreased by employing the gate insulator having geometrical wall structure of mixed shape. Finally, the obtained empirical results were analyzed by simulation of electric field distribution at/near the tip apex and gate insulator using SNU-FEAT simulator.

• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.242-245
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• 2011

In this study, we described and illustrated an unrecorded species from the Korean flora, Sciaphila nana Blume, which is included in the order Pandanales and the family Triuridaceae. This taxon was found at Mul Oreum in Namwon-eup, Seogwipo-si, Jeju Special Self-Governing Province for the first time in Korea. The order Pandanales can be distinguished from the order Liliales by the anomocytic or tetracytic stomata and syncarpous or apocarpous gynoecia of the Pandanales. The family Triuridaceae and the other four taxa in the Pandanales, Cyclanthaceae, Pandanaceae, Stemonaceae, and Velloziaceae, are easily distinguished because the Triuridaceae are microtrophic herbs with scaly leaves. S. nana has a subulate style with a glabrous apex, ovate to narrow ovate leaves and bracts, male perianth segments with a knob-like structure at the apex, and a dimorphic perianth. Therefore, it is easily distinguished from S. tenella, S. multiflora, S. secundiflora, S. thaidanica, S. ramosa, and S. arfakiana.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.203-206
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• 2009

Articulation Index(AI) is the one of the evaluating methods for the interior sound of the automobiles. The AI measures the articulation level of the sound in the vehicle cabin as passengers talk to another. In this study, the effects of AI were investigated according to the various structures of tire. As the structures of tire were changed, the road noise of the vehicle tire was measured using objective measurement. From this measurement data, the AI was calculated. The AI of front is larger than that of rear. Increasing the tread hardness of tire or decreasing the apex height the AI is improved.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1343-1346
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• 2006

Optical performances of micro-pyramid arrays were simulated by ray tracing technique for the application of backlight unit of LCD. The angular distribution of the luminance and the on-axis luminance gain depended on the apex angle, the refractive index, and the density of micro-pyramids. The on-axis luminance reached a maximum when the apex angle was $90^{\circ}$. It also increased as the density and the refractive index of micro-pyramids increased. The present result showed that highly-efficient optical sheet might become realized by adopting micropyramid array and corresponding development of manufacturing processes.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.145-150
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• 2003

16 APEX floats, autonomous profiling floats deployed as part of the Array for Real-time Geostrophic Oceanography (ARGO) program, are used to understand the currents at 800 m underwater in the southwestern East Sea. The flow penetrates into the Ulleung basin (UB) through two paths： an extension of the southward flowing the North Korean Cold Water along the east coast of Korea and between Ulleung Island and Dok island. Flows at 800 m are observed range 0.2 to 4.29 cm/sec and the variability in the north in the DB is stronger than that in the south. The eddy kinetic energy is found a few $cm^{2}$ $S^{-2}$. In the UB, cyclonic flows from 0.3 - 1.6 cm/see are observed with the bottom topography.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.463-465
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• 2001

웹을 이용한 많은 양의 데이터의 분산 처리 방식이 XML 등장 이후 보다 가속화 되고 있다. 하지만 지금까지의 어플리케이션간 데이터 전달 방식은 단순히 데이터의 직렬화와 데이터를 처리하기 위한 외부 함수 호출 등의 전달을 위주로 제안된 XML 프로토콜을 중심으로 개선되어 왔다. 이에 본 논문에서 제안하는 APEX(Application Program Embedded XML) 시스템은 방대한 양의 데이터를 분산된 각 MiniServer에서 기존의 어플리케이션 혹은 사용자가 직접 제공한 어플리케이션을 통해 처리하여 그 결과 값을 원 데이터와 어플리케이션과 함께 데이터베이스에 HTML 문서와 XML 문서의 형태로 저장한 후, 사용자에게 되돌려주는 시스템으로 대용량 데이터 처리에 드는 비용을 줄여주는 효과를 보인다.

• Applied Microscopy
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• v.46 no.3
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• pp.155-159
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• 2016

This paper analyses the relationship between the distribution of a dielectric layer on the apex of a metal field electron emitter and the distribution of electron emission. Emitters were prepared by coating a tungsten emitter with a layer of epoxylite resin. A high-resolution scanning electron microscope was used to monitor the emitter profile and measure the coating thickness. Field electron microscope studies of the emission current distribution from these composite emitters (Tungsten-Clark Electromedical Instruments Epoxylite resin [Tungsten/CEI-resin emitter]) have been carried out. Two forms of image have been observed: bright single-spot images, thought to be associated with a smooth substrate and a uniform dielectric layer; and multi-spot images, though to be associated with irregularity in the substrate or the dielectric layer.

• Journal of Mechanical Science and Technology
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• v.20 no.11
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• pp.1848-1862
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• 2006

As a basic study on the fluid-structure interaction of the shell structure, a theoretical formulation has been suggested on the free vibration of a thin-walled conical frustum shell filled with an ideal fluid, where the shell is assumed to be fixed at both ends. The motion of fluid coupled with the shell is determined by means of the velocity potential flow theory. In order to calculate the normalized natural frequencies that represent the fluid effect on a fluid-coupled system, finite element analyses for a fluid-filled conical frustum shell are carried out. Also, the effect of apex angle on the frequencies is investigated.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.298-300
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• 2001

XML의 등장 이후 인터넷을 이용한 다량의 데이터의 분산 처리 방식이 보다 가속화되고 있다. 이에 본 논문에서는 이러한 분산 처리의 개념을 다수의 수신자에게 같은 내용의 이메일을 보내는 경우에 적용을 하고자 한다. 사용자는 한 사람의 수신자에게 메일을 보내는 것과 같이 메일 에이전트를 통해 메일을 보낼 수 있으나 메일 에이전트는 수신자의 수와 내용의 크기를 토대로 분산되어 있는 메일 시스템인 APEX-MAIL(Application Program Embedded XML-MAIL) 시스템의 각 서버로 메일의 내용과 수신자들의 목록을 XML문서로 만들어 보내며 XML문서를 전송 받은 메일서버들은 각각의 수신자에게 메일을 보내는 것이다. 따라서 본 논문에서 제안하는 APEX-MAIL 시스템은 대용량의 메일을 보냄에 있어 드는 비용을 효과를 줄여주는 효과를 보인다.