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Electrical Bistable Characteristics of Organic Charge Transfer Complex for Memory Device Applications

  • Lee, Chang-Lyoul
    • Applied Science and Convergence Technology
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    • v.24 no.6
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    • pp.278-283
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    • 2015
  • In this work, the electrical bistability of an organic CT complex is demonstrated and the possible switching mechanism is proposed. 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and tetracyanoquinodimethane (TCNQ) are used as an organic donor and acceptor, respectively, and poly-methamethylacrylate (PMMA) is used as a polymeric matrix for spin-coating. A device with the Al/($Al_2O_3$)/PMMA:BCP:TCNQ[1:1:0.5 wt%]/Al configuration demonstrated bistable and switching characteristics similar to Ovshinsky switching with a low threshold voltage and a high ON/OFF ratio. An analysis of the current-voltage curves of the device suggested that electrical switching took place due to the charge transfer mechanism.

Impedance analysis of electrochemical systems using an ion-conducting polymer electrolyte membrane (전도성 고분자 전해질막을 이용하는 전기화학적 시스템의 임피던스 해석)

  • Park, Jin-Soo;Moon, Seung-Hyeon;Kim, Chang-Soo
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.05b
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    • pp.1-8
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    • 2004
  • Ion-conducting polymer electrolyte membranes (PEMs) have recently used in developing fuel cell or solar cell for portable, mobile and residential applications [1]. Polymer electrolyte membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC), alkaline electrolyte fuel cell (AFC) and dye-sensitized solar cell have been employing the ion-conducting PEMs to complete their electrical circuits to produce electricity.(omitted)

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Bacterial Communities in Microbial Fuel Cells Enriched with High Concentrations of Glucose and Glutamate

  • Choo Yeng-Fung;Lee Ji-Young;Chang In-Seop;Kim Byung-Hong
    • Journal of Microbiology and Biotechnology
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    • v.16 no.9
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    • pp.1481-1484
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    • 2006
  • In this study, glucose and glutamate (copiotrophic conditions) were used to enrich electrochemically active bacteria (EAB) in a microbial fuel cell (MFC). The enriched population consisted primarily of ${\gamma}$-Proteobacteria (36.5%), followed by Firmicutes (27%) and O-Proteobacteria (15%). Accordingly, we compared our own enrichments done under many different conditions with those reported from the literature, all of which support the notion that electrochemically active bacteria are taxonomically very diverse. Enrichments with different types and levels of energy sources (fuels) have clearly yielded many different groups of bacteria.

Activation Strategies of Non-government Certification Using SWOT/AHP Analysis (SWOT/AHP 분석을 이용한 민간인증제도 활성화 전략)

  • Goh, Hyun-Woo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.32 no.2
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    • pp.104-111
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    • 2009
  • Recently, it is becoming the big issue internationally where the safety problem of the industrial product including the foodstuffs. The way is able to construct the trust of the consumer that the external specialized agency independently operating confirms what production process of the product keep a standard or a technical regulation. This is conformity assessment. In the many countries, agencies entrusted government authority do conformity assessment. Specially, 'certification' in one form of conformity assessment process is operating a certification system at the government and the non-government body in Korea. Also non-government certification is fixed by trusted system from consumer. He has to prepare a competitive power in liberalization time, so need the countermeasure urgently. This study purpose that develops strategy so as to activating of non-government certification system in gist of the origination called 'self-control.' I present activation strategies using SWOT/AHP analysis.

Reversible Image Authentication Using Histogram of Difference Image (차분 영상의 히스토그램을 이용한 무손실 영상 인증 방법)

  • Lee, Sang-Kwang;Suh, Young-Ho;Ho, Yo-Sung
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.407-408
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    • 2006
  • In this paper, we propose a new reversible image authentication technique based on watermarking where if the image is authentic, the distortion due to embedding can be completely removed from the watermarked image after the hidden data has been extracted. This technique utilizes histogram characteristics of the difference image and modifies pixel values slightly to embed more data than other reversible data hiding algorithm. The proposed scheme is quite simple and the execution time is rather short. Experimental results demonstrate that the proposed scheme can detect any modifications of the watermarked image.

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High performance inkjet printed polymer CMOS integrated circuits

  • Baeg, Kang-Jun;Kim, Dong-Yu;Koo, Jae-Bon;Jung, Soon-Won;You, In-Kyu;Noh, Yong-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.67-70
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    • 2009
  • Printed electronics are emerging technology to realize various microelectronic devices via a cost-effective method. Here we introduce high performance inkjet printed polymer field-effect transistors and application to complementary integrated circuits with p-type and n-type conjugated polymers. The performance of devices highly depends on the selection of dielectrics, printing condition and device architecture. The device optimization and performances of various integrated circuits, e.g., complementary inverters and ring oscillators will be mainly discussed in this talk.

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Development of Highly Stable Organic Nonvolatile Memory

  • Baeg, Kang-Jun;Kim, Dong-Yu;You, In-Kyu;Noh, Yong-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.904-906
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    • 2009
  • Organic field-effect transistor (OFET) memory is an emerging device for its potential to realize light-weight, low cost flexible charge storage media. Here we report on a solution-processed poly[9,9-dioctylfluorenyl-2,7-diyl]-co-(bithiophene)] (F8T2) nano floating-gate memory (NFGM) with top-gate/bottom-contact device configuration. A reversible shift in the threshold voltage ($V_{Th}$) and the reliable memory characteristics were achieved by incorporation of thin Au nanoparticles (NPs) as charge storage sites for negative electrons at the interface between polystyrene and cross-linked poly(4-vinylphenol).

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Generation of 1.5 Gbps Pseudo-random Binary Sequence Optical Signals by Using a Gain Switched Fabry-Perot Semiconductor Laser

  • Kim Dae-Geun;Woo Sae-Yoon;Kim Dong-Kwan;Hwang Taek-Yong;Park Seung-Han;Kim Dug Young
    • Journal of the Optical Society of Korea
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    • v.9 no.3
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    • pp.103-106
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    • 2005
  • Recently, polymethyl methacrylate based plastic optical fibers (POFs) have attracted considerable attention as a potential medium for local area network (LAN) and home network applications. Since the POFs have very low optical loss at around 650mm, in particular, it becomes quite important to develop GHz transmitters operating at this wavelength for high bit rate optical transmission applications of the POFs. In this paper, we present generation of ${\geq}1.5 Gbps$ pseudo-random binary sequence optical signals by using a gain switched InGaA1P Fabry-Perot semiconductor laser with a high frequency filter, operating at 650mm, and the application of these signals to bandwidth measurement of POFs.

Statistical Error Compensation Techniques for Spectral Quantization

  • Choi, Seung-Ho;Kim, Hong-Kook
    • Speech Sciences
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    • v.11 no.4
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    • pp.17-28
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    • 2004
  • In this paper, we propose a statistical approach to improve the performance of spectral quantization of speech coders. The proposed techniques compensate for the distortion in a decoded line spectrum pairs (LSP) vector based on a statistical mapping function between a decoded LSP vector and its corresponding original LSP vector. We first develop two codebook-based probabilistic matching (CBPM) methods based on linear mapping functions according to different assumption of distribution of LSP vectors. In addition, we propose an iterative procedure for the two CBPMs. We apply the proposed techniques to a predictive vector quantizer used for the IS-641 speech coder. The experimental results show that the proposed techniques reduce average spectral distortion by around 0.064dB.

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