• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1420-1423
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• 1997

To make clearly breakdown rl1cchanism and path at interface of crystal and amorphous region, we fabricated HDPE and LDPE thin film by dropping solution onto glass substrate. then annealed the film at $140^{\circ}C$. Shperulites formation and its interface prepared from of two different materials differ from each other. Comparing breakdown site and breakdown field of HDPE with those of LDPE, we can demonstrate the reason that breakdown holes in HDPE are concentrated on the region of interface. From the result, It is appeared that interface of crystallites lead not to weakness as electrical insulating materials.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권1호
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• pp.34-39
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• 2014

This paper discusses the 3-level charge pumping (CP) method in planar-type Silicon-Oxide-High-k-Oxide-Silicon (SOHOS) and Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) devices to find out the reason of the degradation of data retention properties. In the CP technique, pulses are applied to the gate of the MOSFET which alternately fill the traps with electrons and holes, thereby causing a recombination current Icp to flow in the substrate. The 3-level charge pumping method may be used to determine not only interface trap densities but also capture cross sections as a function of trap energy. By applying this method, SOHOS device found to have a higher interface trap density than SONOS device. Therefore, degradation of data retention characteristics is attributed to the many interface trap sites.

• E2M - 전기 전자와 첨단 소재
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• 제7권3호
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• pp.231-235
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• 1994

The multi-dielectric layer $SiO_2$/$Si_3{N_4}$/$SiO_2$ (ONO) is used to improve charge retention and to scale down the memory device. The nitride layer of MNOS device is oxidize to form ONO system. During the oxidation of the nitride layer, the change of thickness of nitride layer and generation of interface state between nitride layer and top oxide layer occur. In this paper, effects of oxidation of the nitride layer is studied. The decreases of the nitride layer due to oxidation and trapping characteristics of interface state of multi layer dielectric film are investigated through the C-V measurement and F-N tunneling injection experiment using SONOS capacitor structure. Based on the experimental results, carrier trapping model for maximum flatband voltage shift of multi layer dielectric film is proposed and compared with experimental data. As a results of curve fitting, interface trap density between the top oxide and layer is determined as being $5{\times}10^11$~$2{\times}10^12$[$eV^1$$cm^2$].

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.82-85
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• 1992

In this study, charge pumping method was used to investigate the Si-SiO$_2$interface characteristics of the nonvolatile SNOSFET memory devices, fabricated using the CMOS 1 Mbit processes (1.2$\mu\textrm{m}$ design rule), with thin oxide layer of 30${\AA}$ thick and nitride layer of 525${\AA}$ thick on the n-type silicon substrate (p-channel). Charge pumping current characteristics with the pulse base level were measured for various frequencies, falling times and rising times. By means of the charge dynamics in a non-steady state, the average Si-SiO$_2$interface state density and capture cross section were determined to be 3.565${\times}$10$\^$11/cm$\^$-2/eV$\^$-1/ and 4.834${\times}$10$\^$-16/$\textrm{cm}^2$, respectively. However Si-SiO$_2$ interface state densities were disributed 2.8${\times}$10$\^$-11/～5.6${\times}$10$\^$11/cm$\^$-2/～6${\times}$10$\^$11/cm$\^$-2/eV$\^$-1/ in the lover half of energy gap.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2004년도 추계 학술발표회 논문집
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• pp.133-138
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• 2004

Proton exchange membrane fuel cell (PEMFC) is considered as a clean and efficient energy conversion det ice for mobile and stationary applications. Anions all the components of the PEMFC, the interface between the electrolyte ,and electrode catalyst plays an important role in determining tile cell performance since the electrochemical reactions take place at the interface in contact with tile reactant gases. Therefore, to increase the interface area and obtain a high-performance PEMFC, surface of the electrolyte membrane was roughened by Ar$^{+}$ beam bombardment. The results imply that by modifying surface of the electrolyte membrane, platinum loading can be reduced significantly without performance loss. To optimize the surface treatment condition, effects of ion dose density on characteristics of the membrane/electrode interface were examined by measuring the cell performance, impedance spectroscopy, and cyclic voltammograms. Surface of the modified membranes were characterized using scanning electron microscopy and FT-IR.R.

• 전자공학회논문지A
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• 제31A권12호
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• pp.56-63
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• 1994

The effects of sulfur treatments on the barrier heithts of Schottky contacts and the interface-state density of metal-insulator-semiconductor (MIS) capacitors on InP have been investigated. Schottky contacts were formed by the evaporation of Al, Au, and Pt on n-InP substrate before and after (NH$_{4}$)$_{2}$S$_{x}$ treatments, respectively. The barrier height of InP Schottky contacts was measured by their current-voltage (I-V) and capacitance-voltage (C_V) characteristics. We observed that the barrier heights of Schottky contacks on bare InP were 0.35~0.45 eV nearly independent of the metal work function, which is known to be due to the surface Fermi level pinning. In the case of sulfur-treated Au/InP ar Pt/InP Schottky diodes, However, the barrier heights were not only increased above 0.7 eV but also highly dependent on the metal work function. We have also investigated effects of (NH$_{4}$)$_{2}$S$_{x}$ treatments on the distribution of interface states in Si$_{3}$N$_{4}$InP MIS diodes where Si$_{3}$N$_{4}$ was provided by plasma enhanced chemical vapor deposition (PECVD). The typical value of interface-state density extracted feom 1 MHz C-V curve of sulfur-treated SiN$_{x}$/InP MIS diodes was found to be the order of 5${\times}10^{10}cm^{2}eV^{1}$. This value is much lower than that of MiS diodes made on bare InP surface. It is certain, therefore, that the (NH$_{4}$)$_{2}$S$_{x}$ treatment is a very powerful tool to enhance the barrier heights of Au/n-InP and Pt/n-InP Schottky contacts and to reduce the density of interface states in SiN$_{x}$/InP MIS diode.

• 한국지반공학회논문집
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• 제37권3호
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• pp.31-41
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• 2021

도저는 토공사 현장에서 부지를 평탄화하거나 토사를 모으기 위해 사용되는 장비이다. 도저의 성능은 지반-궤도 접지면에서 발현되는 지반추력에 의해 결정되는데, 주어진 조건에서 최대한의 지반추력을 발현시키기 위해서 무한궤도 표면에 그라우저를 부착하는 것이 일반적이다. 본 연구에서는 다양한 형상비를 가지는 그라우저가 부착된 도저의 지반추력을 산정하고, 이를 바탕으로 지반 특성을 고려한 최적 그라우저 형상비를 평가했다. 그라우저는 궤도 측면에서 추가적인 지반추력(측면지반추력)을 발현시키고 지반-궤도 사이의 전단을 지반-지반 사이의 전단으로 전환시켜, 도저의 지반추력을 약 1.3~1.6배 증가시켰다. 그라우저 형상비가 지반추력에 미치는 영향은 도저가 구동하는 지반의 다짐도에 따라 다르게 나타났다. 느슨한 지반에서는 형상비가 작은 그라우저가, 조밀한 지반에서는 형상비가 큰 그라우저가 도저의 지반추력을 가장 크게 증가시킬 수 있는 최적의 형상으로 평가되었다. 무한궤도에 지반의 다짐도를 고려한 최적 그라우저를 부착한다면 도저의 작업 성능을 보다 크게 강화할 수 있을 것이며, 이를 통해 장비의 효율적 활용 및 토공사 생산성 향상이 가능할 것으로 기대된다.

• Journal of the korean society of oceanography
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• 제31권4호
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• pp.173-182
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• 1996

A median-density fluid was injected into the upper layer of a two-layered fluid in a rotating cylindrical container. Several sets of the top and bottom boundary configurations were employed and the flow pattern of each layer including the injected fluid was observed to determine the factors that affect the path of the injected intermediate fluid. The axisymmetric path of the intermediate fluid when the upper layer had a free surface, changed into the asymmetric path with bulged-shape radial spreading whenever either the upper layer or the lower layer had ${\beta}$-effect. The internal Fronds number that controls the shape of the interface turned out to be the most important parameter that determines the radial spreading in terms of location and strength. When the upper and lower layer had the ${\beta}$-effect, convective overturning produced anticyclonic vortices at the frontal edge of the intermediate fluid, and that could enhance the vertical mixing of different density fluids. The intermediate fluid did not produce any topographic effect on the upper-layer motion during its spreading over the interface, since its thickness was very small. However, its anticyclonic motion within the bulged-shape produced a cyclonic motion in the lower layer just beneath the bulge.

• Corrosion Science and Technology
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• 제12권1호
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• pp.34-39
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• 2013

In this study, the effect of niobium addition on the passivation behavior of Ti alloys in NaCl solution was investigated using various electrochemical methods. An ${\alpha}$-phase in Ti alloy was transformed into a ${\beta}$-phase and martensite structure decreased as Nb content increased. The corrosion and passivation current density($+300mV_{SCE}$) decreased as Nb content increased, and thereby a stable passive film was formed on the Ti alloy. Potential of Ti-xNb alloy in the passive region increased, whereas, current density decreased with time from results of potentiostatic and galvanostatic tests. Also, the corrosion morphology showed the smaller pits as Nb content increased. Consequently, Ti alloy contained high Nb content showed a good resistance to pitting corrosion in 0.9% NaCl solution.

• 한국지능시스템학회논문지
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• 제25권3호
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• pp.254-259
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• 2015

본 논문은 BCI(Brain Computer Interface)기반의 정상상태시각유발전위(SSVEP : Steady-State Visual Evoked Potential)를 사용하여 무선 로봇 제어를 위한 시스템을 제안하였다. CPSD(Cross Power Spectral Density)를 사용하여 전극의 신호를 분석하였다. 또한 분류를 위해서 LDA(Linear Discriminant Analysis)와 SVM(Support Vector Machine)을 사용하였다. 그 결과 피험자들의 평균 분류율은 약 70%로 나타났다. 로봇제어의 경우 뇌파의 값을 분류하여 나타난 결과 값으로 로봇이 움직일 수 있도록 구현하였고, 블루투스 통신을 이용하여 로봇제어를 수행하였다.