• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 추계학술대회 논문집
• /
• pp.480-483
• /
• 2000

Polyimide is a well-known organic dielectric material, which has not only high chemical and thermal stability but also good electrical insulating and mechanical properties. In this research, the electrical properties of PI LB films were investigated at room temperature. At low electric field, ohmic conduction(I∝V) was observed and the calculated electrical conductivity was about 9.7$\times$10$^{-15}$ S/cm. At high electric field, conduction(I∝V$^2$) was observed and the conduction mechanism was explained by space charge limited region effect. The dielectric constant of LB film was about 7.5.

• The Korean Journal of Ecology
• /
• 제22권5호
• /
• pp.265-270
• /
• 1999

전라남도의 해안에 방치된 염전에 생육하고 있는 식생에 대하여 군락 분류학적 연구와 토양의 특성에 대한 연구가 수행되었다. 본 연구는 종조성을 바탕으로 Mueller-Dombois와 Ellenberg 법에 따라 수행되었다. 본 연구의 목적은 전남 해안에 방치되어 있는 폐염전의 식물군락분류를 통한 식생형을 규정하고, 군락생태를 밝히는데 있다. 폐염전에 분포하는 일년생 초본 염생식물군락은 퉁퉁마디군락, 칠면초군락, 해홍나물군락, 가는갯능쟁이군락, 갯개미자리군락으로 밝혀졌다. 그리고 다년생 초본 염생식물군락으로는 갯개미취군락, 천일사초군락, 갈대군락으로 분류되었다. 본 연구의 결과는 해안 습지 식생에 대한 군락분류 및 구성종에 대한 정보의 축적을 가능하게 하고, 아울러 해안 습지 생태계 보전을 위한 기초자료로 유용한 정보를 제공한다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.696-699
• /
• 2004

Of the emissive display technologies, field emission displays using pasted carbon nanotubes offer several advantages over other competing cathode materials such as low driving voltage, possible large-area and low-cost processes. In this study, formulation of carbon nanotube paste and its electron field emission properties are characterized. Also the effects of additive powders and surface morphology on electron emission are reported.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
• /
• pp.362-364
• /
• 1993

The properties of near-field diffraction by small aperture are investagated and using of optical fiber taper as a small aperture are proposed. Near-field diffracted by aperture smaller than one wave length can overcome the resolution of conventional microscopy and optical component. In this paper production methods of sub-wave length optical fiber taper using solenoid are also proposed.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
• /
• pp.29-32
• /
• 1998

In this paper, the properties of the agitation noise of agitator truck when flowing concrete practice is applied in construction field of our country are investigated. According to the experimental results, the solution on the noise during the agitation in flowing concrete should be considered in order to apply flowing concrete into construction field without the problems such as a civil appeal.

• 전기의세계
• /
• 제21권4호
• /
• pp.7-14
• /
• 1972

The author has established a general equation for the travelling magnetic field in air gap with the end effect taken into consideration, which constitutes the basics for the analysis of characteristics of linear induction motor. This equation is verified by comparison of the experimental values with the theoretically calculated values. The properties of the travelling wave with attenuation, which is contained in the travelling magnetic field of linear induction motor, have been verified, and consequently the practicable equation is established with these effects taken into consideration. This provides the solid foundation for the theoretical analysis of the characteristics of the linear induction motor.

• 대한수학회논문집
• /
• 제16권4호
• /
• pp.637-648
• /
• 2001

An n-dimensional ME-manifold ME $X_{n}$ is a general-ized Riemannian manifold connected by the ME-connection which is both Einstein and of the form (2.13). The purpose of this paper is to study the properties of the ME-curvature tensors, the con-tracted ME-curvature tensors and the field equations in ME $X_{n}$)n)

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.217-217
• /
• 2016

The amorphous InGaZnO (a-IGZO) is widely accepted as a promising channel material for thin-film transistor (TFT) applications owing to their outstanding electrical properties [1, 2]. However, a-IGZO TFTs have still suffered from their bias instability with illumination [1-4]. Up to now, many researchers have studied the sub-gap density of states (DOS) as the root cause of instability. It is well known that defect states can influence on the performances and stabilities of a-IGZO TFTs. The defects states should be closely related with the deposition condition, including sputtering power, and pressure. Nevertheless, it has not been reported how these defects are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOIs) can be generated by electron attachment in oxygen atom near target surface and then accelerated up to few hundreds eV by a self-bias; at this time, the high energy bombardment of NOIs induce defects in oxide thin films. Recently, we have reported that the properties of IGZO thin films are strongly related with effects of NOIs which are generated during the sputtering process [5]. From our previous results, the electrical characteristics and the chemical bonding states of a-IGZO thin films were depended with the bombardment energy of NOIs. And also, we suggest that the deep sub-gap states in a-IGZO as well as thin film properties would be influenced by the bombardment of high energetic NOIs during the sputtering process.In this study, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process to prevent the NOIs bombardment effects and present how much to be improved the properties of a-IGZO thin film by this new deposition method. We deposited a-IGZO thin films by MFSS on SiO2/p-Si and glass substrate at various process conditions, after which we investigated the morphology, optical and electrical properties of the a-IGZO thin films.

• 한국산학기술학회논문지
• /
• 제14권7호
• /
• pp.3550-3561
• /
• 2013

본 연구는 문화재로 지정된 주요 목조 건축물을 방재(특히 화재예방)의 관점에서 안전하게 보호하고 피해를 최소화할 수 있는 방안마련을 위한 기초연구로서, 목조 건축문화재의 방재현황(화재 위험도)을 평가할 수 있는 지표와 활용방안 제안을 목적으로 체크리스트를 작성하여 현장조사를 실시하는 방법으로 진행되었다. 체크리스트는 관리 운영 대응의 관리운영, 배치계획 시설계획의 건축계획, 소방시설 방범시설의 설비계획으로 구성하였다. 내장사와 화엄사를 대상으로 실시한 현장조사에서는 중요도가 높은 항목들에 여러 가지 문제점이 있는 것으로 나타났다.

• 한국안전학회지
• /
• 제33권2호
• /
• pp.152-157
• /
• 2018

The degradation and damage of the components for ballasted track could be caused a serious problem for railway safety. Therefore, the integrity evaluation of ballasted track condition is important to ensure and predict that the track safety and track maintenance. Various track components such as rail pad, ballast, sleeper, and rail that are widely used in Republic of Korea and represent a range of physical properties have been selected for this research. In this study, the experimental modal analysis was performed by the non-destructive testing. Modal test results were obtained from the field test and used to assess the condition of the track components. From the field test, the system of ballasted track was found to be simplified as a two-degree-of-freedom(2DOF) dynamic system. The condition of track component was found to directly affect the dynamic response of ballasted tracks. As the results, the dynamic properties of the track component was depend on the track condition and was distributed more roughly and over a wider range than its initial design values. Further, the methodology presented in this study is possible to determine experimentally the fundamental track parameters which are required in the numerical analysis, and also are useful for the safety assessment of track condition.