• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.783-793
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• 1997

A VLSI implementation of a self-learning neural network integrated circuits using a linearity synapse transistor is investigated. The thickness dependence of oxide current density stress current transient current and channel current has been measured in oxides with thicknesses between 41 and 112 $\AA$, which have the channel width $\times$ length 10 $\times$1${\mu}{\textrm}{m}$, 10 $\times$ 0.3${\mu}{\textrm}{m}$ respectively. The transient current will affect data retention in synapse transistors and the stress current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor has represented the neural states and the manipulation which gaves unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the drain source current.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.59-62
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• 2000

A VLSI implementation of a self-learning neural network integrated circuits using a linearity synapse transistor is investigated. The thickness dependence of oxide current density, stress current, transient current and channel current has been measured in oxides with thicknesses between 41 and 112 $\AA$, which have the channel width$\times$length 10$\times$1${\mu}{\textrm}{m}$ respectively. The transient current will affect data retention in synapse transistors and the stress current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor has represented the neural states and the manipulation which gave unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the drain source current.

• 한국전자파학회논문지
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• 제16권9호
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• pp.957-963
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• 2005

본 논문에서는 TSMC 0.25 ${\mu}m$ CMOS RF-Mixed mode 공정 기술을 이용하여 초고속 광통신 시스템의 수신부에 사용되는 광대역 transimpedance amplifier를 설계하였다. 특히 광대역을 구성하기 위해 cascode와 common-source 구조에 active inductor shunt peaking을 이용하여 설계 및 제작하였으며, 측정 결과 gain 변화 없이 -3 dB 대역폭 특성이 cascode는 0.8 GHz에서 $81\%$ 증가한 1.45 GHz, common-source는 0.61 GHz에서 $48\%$ 증가한 0.9 GHz 결과가 나왔으며, 전체 파워 소비는 바이어스 2.5 V를 기준으로 37 mW와 45 mW이며, transimpedance gain은 61 dB$\Omega$과 61.4 dB$\Omega$을 얻을 수 있었다. 그리고 input noise current density도 상용 TIA와 거의 비슷한 $5 pA/\sqrt{Hz}$와 $4.5 pA/\sqrt{Hz}$를 가지며, out put Return loss는 전 대역에서 -10 dB 이하의 정합 특성을 보였다. 그리고 전체 chip 사이즈는 $1150{\times}940{\mu}m^2$이다.

• 한국인지과학회:학술대회논문집
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• 한국인지과학회 2005년도 춘계학술대회
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• pp.151-153
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• 2005

We investigated the brain substrate of repetition priming on the implicit memory taskusing low-resolution electromagnetic tomography (LORETA) with high-density 128 channel EEG and individual MRI as a realistic head model. Thirteen right-handed, healthy subjects performed a word/nonword discrimination task, in which the words and nonwords were presented visually,and some of the words appeared twice with a lag of one or five items. All of the subjects exhibited repetition priming with respect to the behavioral data, in which a faster reaction time was observed to the repeated word (old word) than to the first presentation of the word (new word). The old words elicited more positive-going potentials than the new words, beginning at 200 ms and lasting until 500 ms post-stimulus. We conducted source reconstruction using LORETA at a latency of 400 ms with the peak mean global field potentials and used statistical parametric mapping for the statistical analysis. We found that the source elicited by the old words exhibited a statistically significant current density reduction in the left inferior frontal gyrus. This is the first study to investigate the generators of repetition priming using voxel-by-voxel statistical mapping of the current density with individual MRI and high-density EEG.

• Journal of Radiation Protection and Research
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• 제31권2호
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• pp.105-113
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• 2006

사용후핵연료의 처분을 위해 사용되는 캐니스터 주변 완충재의 공극 내 지하수는 방사분해에 의해 산화제를 발생한다. 캐니스터 주변의 탄소강의 부식을 결정하는 산화제에 의해 야기된 음 전류 밀도를 계산하기 위하여 수학적 모델을 이용하였다. 실린더 좌표계에서 음 전류 밀도를 구할 수 있는 해석해를 유도하였다. 직교 좌표계와 실린더 좌표계에서 구한 음 전류 밀도를 서로 비교하였다. 방사분해 계산을 위한 선원항 및 흡수선량률은 ORIGEN2와 MCNP 컴퓨터 코드를 이용하여 계산하였다. 새로운 모델을 이용하여 부식을 억제할 수 있는 처분용기 반경을 결정하였다. 계산 결과 실린더 좌표계에서의 해를 이용할 경우 기존의 Marsh 모델보다 음 전류 밀도 값을 25 % 감소시켰다.

• Current Applied Physics
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• 제18권11호
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• pp.1415-1421
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• 2018

Unlike ordinary organic field-effect transistors (OFETs), saturation current is hardly to be found in vertical OFETs (VOFETs). Moreover, the fabrication process of patterned sourced for VOFETs is quite complex. In this current work, a simple solution processed VOFET with directly deposited intermediate silver source electrode has been demonstrated. The VOFET exhibits a high leakage current that induces an inversion polarity of its transistor behavior. Interestingly, a well-defined saturation current was observed in the linear scale of transfer characteristic. The VOFET operated with high-current density > $280mA/cm^2$ at $V_d=5V$. Overview potential of the fabricated device in display application is also presented. This preliminary work does open-up a new direction in VOFET fabrication and their application.

• 한국재료학회지
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• 제32권7호
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• pp.320-325
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• 2022

Single OLED and tandem OLED was manufactured to analyze the electroluminescence characteristics of DC driving, AC driving, and full-wave rectification driving. The threshold voltage of OLED was the highest in DC driving, and the lowest in full-wave rectification driving due to an improvement of current injection characteristics. The luminance at a driving voltage lower than 10.5 V (8,534 cd/m²) of single OLED and 20 V (7,377 cd/m²) of a tandem OLED showed that the full-wave rectification drive is higher than that of DC drive. The luminous efficiency of OLED is higher in full-wave rectification driving than in DC driving at low voltage, but decrease at high voltage. The full-wave rectification power source may obtain higher current density, higher luminance, and higher current efficiency than the AC power source. In addition, it was confirmed that the characteristics of AC driving and full-wave rectification driving can be predicted from DC driving characteristics by comparing the measured values and calculated values of AC driving and full-wave rectification driving emission characteristics. From the above results, it can be seen that OLED lighting with improved electroluminescence characteristics compared to DC driving is possible using full-wave rectification driving and tandem OLED.

• Journal of Korean Vacuum Science & Technology
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• 제5권1호
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• pp.19-24
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• 2001

The paper represents the results of the development and the test of "cold cathode" ion source model with 5 cm aperture where the glow discharge is utilized for generation of electrons in the cathode of the ion source. The results of probe measurements of the ion source are represented. The integral parameters such as electron energy distribution function(EEDF), electron density and mean electron energy, discharge voltage-current characteristics, and distribution of ion beam were studied.

• Transactions on Electrical and Electronic Materials
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• 제18권3호
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• pp.176-179
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• 2017

Non-vacuum processing technology was used to produce $Cs_3Sb$ photocathodes on substrates and fabricate in-situ panel devices. Electrical properties of these panel devices were characterized by measuring anode current and charge dose as functions of devices operation time. An excitation light source with a 475 nm wavelength was used for photocathodes. Results showed that emission properties of these photocathode emitters depended heavily on the vacuum level of these devices and that $Cs_3Sb$ flat emitters had the potential of operating for a long lifetime with stable electron emission characteristics via re-cesiation process in the panel device. These features make $Cs_3Sb$ photocathodes suitable as flat emitters in panel device applications.

• ETRI Journal
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• 제24권5호
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• pp.333-340
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• 2002

We propose a new process technique for fabricating very high-density trench MOSFETs using 3 mask layers with oxide spacers and a self-aligned technique. This technique reduces the device size in trench width, source, and p-body region with a resulting increase in cell density and current driving capability as well as cost-effective production capability. We were able to obtain a higher breakdown voltage with uniform oxide grown along the trench surface. The channel density of the trench DMOSFET with a cell pitch of 2.3-2.4 ${\mu}m$ was 100 Mcell/$in^2$ and a specific on-resistance of 0.41 $m{\Omega}{\cdot}cm^2$ was obtained under a blocking voltage of 43 V.