• 한국전자통신학회논문지
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• 제11권9호
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• pp.877-884
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• 2016

나노 통신 시스템 기술은 통신기술과 나노기술의 융합 분야로서 밀리미터 수준의 통신 모듈 크기에 머물고 있는 현 기술수준을 뛰어넘어 수백 나노미터에서 수십 마이크로미터 이하 단위의 극소형 무선통신 시스템 구현을 가능케 하는 미래 핵심 기술 분야이다. 특히, 최근 제안된 탄소나노튜브의 전기적/기계적 속성을 활용한 신규 극소형 나노 무선 통신시스템 기술은 기존 송수신 구조를 단순히 소형화하는 것이 아니라 구조 자체를 바꾸는 새로운 접근 방식을 제시하고 있다. 따라서, 본 논문에서는 탄소나노튜브(carbon nanotube, CNT)를 활용한 극소형 나노 무선 송수신기 실현 관점에서의 연구현황을 살펴보고 나노 기술과 통신 기술의 융합을 위한 주요 핵심 연구이슈를 제시한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.236.1-236.1
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• 2015

The surface morphology of front transparent conductive oxide (TCO) films is very important to achieve high current density in amorphous silicon (a-Si) thin film solar cells since it can scatter the light in a better way. In this study, we present the low cost hydrothermal deposited uniform zinc oxide (ZnO) nano-flower structure with various aspect ratios for a-Si thin film solar cells. The ZnO nano-flower structures with various aspect ratios were grown on the RF magnetron sputtered AZO films. The diameters and length of the ZnO nano-flowers was controlled by varying the annealing time. The length of ZnO nano-flowers were varied from 400 nm to $2{\mu}m$ while diameter was kept higher than 200 nm to obtain different aspect ratios. The ZnO nano-flowers with higher surface area as compared to conventional ZnO nano structure are preferred for the better light scattering. The conductivity and crystallinity of ZnO nano-flowers can be enhanced by annealing in hydrogen atmosphere at 350 oC. The vertical aligned ZnO nano-flowers showed higher haze ratio as compared to the commercially available FTO films. We also observed that the scattering in the longer wavelength region was favored for the high aspect ratio of ZnO nano-flowers. Therefore, we proposed low cost and vertically aligned ZnO nano-flowers for the high performance of thin film solar cells.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.5035-5048
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• 2016

Nano scale networks are futuristic networks deemed as enablers for the Internet of Nano Things, Body area nano networks, target tracking, anomaly/ abnormality detection at molecular level and neuronal therapy / drug delivery applications. Molecular communication is considered the most compatible communication technology for nano devices. However, connectivity in such networks is very low due to inter-symbol interference (ISI). Few research papers have addressed the issue of ISI mitigation in molecular communication. However, many of these methods are not adaptive to dynamic environmental conditions. This paper presents an enhancement over original Memory-1 ISI cancellation scheme using maximum likelihood estimation of a channel parameter (λ) to make it adaptable to variable channel conditions. Results of the Monte Carlo simulation show that, the connectivity (P_conn) improves by 28% for given simulation parameters and environmental conditions by using enhanced Memory-1 cancellation method. Moreover, this ISI mitigation method allows reduction in symbol time (Ts) up to 50 seconds i.e. an improvement of 75% is achieved.

• 한국광학회:학술대회논문집
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• 한국광학회 2005년도 하계학술발표회
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• pp.56-57
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• 2005

We have studied on the SLDs utilizing InAs chirped QD structure. The output power and spectral bandwidth are obtained as CW 40 mW at RT and about 100 nm, respectively. More high performance of SLD can be possible with optimized design for the chirped QD structures.

• BMB Reports
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• 제44권1호
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• pp.1-10
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• 2011

Inter-cellular communication via diffusible small molecules is a defining character not only of multicellular forms of life but also of single-celled organisms. A large number of bacterial genes are regulated by the change of chemical milieu mediated by the local population density of its own species or others. The cell density-dependent "autoinducer" molecules regulate the expression of those genes involved in genetic competence, biofilm formation and persistence, virulence, sporulation, bioluminescence, antibiotic production, and many others. Recent innovations in recombinant DNA technology and micro-/nano-fluidics systems render the genetic circuitry responsible for cell-to-cell communication feasible to and malleable via synthetic biological approaches. Here we review the current understanding of the molecular biology of bacterial intercellular communication and the novel experimental protocols and platforms used to investigate this phenomenon. A particular emphasis is given to the genetic regulatory circuits that provide the standard building blocks which constitute the syntax of the biochemical communication network. Thus, this review gives focus to the engineering principles necessary for rewiring bacterial chemo-communication for various applications, ranging from population-level gene expression control to the study of host-pathogen interactions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.102-122
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• 2017

Nanotechnology has provided a set of tools that the engineers can use to design and manufacture integrated nano devices, which are capable of performing sensing, computing, data storing and actuation. One of the main hurdles for nano devices has been the amount of power that it can generate for transmission of data. In this paper, we proposed cooperative nano communication in the Terahertz (THz) Gap frequency band to increase the range of transmission. Outage probability (OP) performances for the proposed cooperative nano communication networks in the THz band (0.1 - 10THz) have been evaluated for the following scenarios; A) A single decode-and-forward (DF) relay over independent identically distributed (i.i.d.) Rayleigh fading channels, B) DF multi-relay network with best relay selection (BRS) over i.i.d. Rayleigh fading channels, and C) DF multi-relay network with multiple hops with BRS over i.i.d. Rayleigh fading channels. The results show that the transmission distance can be improved significantly by employing DF relays. Also, it is shown that by increasing the number of hops in a relay the OP performance is marginally degraded. The analytical results have been verified by Monte-Carlo simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권10호
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• pp.5035-5057
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• 2019

Advancements in nanotechnology and novel nano materials in the past decade have provided a set of tools that can be used to design and manufacture integrated nano devices, which are capable of performing sensing, computing, data storing and actuation. In this paper, we have proposed cooperative nano communication using Power Switching Relay (PSR) Wireless Power Transfer (WPT) protocol and Time Switching Relay (TSR) WPT protocol over independent identically distributed (i.i.d.) Rayleigh fading channels in the Terahertz (THz) Gap frequency band to increase the range of transmission. Outage Probability (OP) performances for the proposed cooperative nano communication networks have been evaluated for the following scenarios: A) A single decode-and-forward (DF) relay for PSR protocol and TSR protocol, B) DF multi-relay network with best relay selection (BRS) for PSR protocol and TSR protocol, and C) DF multi-relay network with multiple DF hops with BRS for PSR protocol and TSR protocol. The results have shown that the transmission distance can be improved significantly by employing DF relays with WPT. They have also shown that by increasing the number of hops in a relay the OP performance is only marginally degraded. The analytical results have been verified by Monte-Carlo simulations.

• 한국광학회지
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• 제32권3호
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• pp.101-107
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• 2021

본 논문에서는 MLA (microlens array)를 이용한 자동차 커뮤니케이션 램프 설계 방안에 대한 연구를 진행하였다. 자율주행기술의 발전으로 보행자와 차량 간의 소통을 위한 커뮤니케이션 램프가 자동차에 필요하게 되었다. 광학계의 크기를 줄이고, 높은 광량을 확보하기 위해 MLA를 사용하여 커뮤니케이션 램프 광학계를 설계하였다. 또한, 기울어진 지면에서 선명한 image를 확보하기 위해 중첩방안을 고려하여 설계를 진행하였다. 이후 중첩 전 MLA 광학계와 성능 비교를 통해 향상된 성능을 확인하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2008년도 추계학술발표대회
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• pp.996-997
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• 2008

배터리를 사용하는 센서노드의 전력 소모를 줄이기 위해 많은 방법들이 제안되어 있다. 본 논문에서는 MCU 및 센서의 전력을 관리하는 전력 매니저를 제안한다. 센서의 타입을 설정하고 제안되어 있는 센서의 추상화를 추가한 매니저를 제안한다. Nano-Q+가 스케줄링할 때 센서의 타입을 판단하여 전원을 관리 할 수 있도록 한다.

• 한국인쇄학회지
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• 제29권3호
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• pp.17-30
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• 2011

The polarizer is an important optical element used in a variety of applications. Nano-wire grid polarizers in the form of sub-wavelength metallic gratings are an attractive alternative to conventional polarizers, because they provide high extinction ratio. This study has been carried out to fabrication of the 17inch area size nano-wire grid polarizer(NWGP) The master for NWGPs with a pitch of 200nm and the area size $730mm{\times}450mm$ were fabricated using laser interference lithography and aluminum sputtering and wet etching. And The NWGP fabrication process was using by the Roll to-Roll UV imprinting and was applied to flexible PET film. The results were a transmission of light (Tp) 46.7%, reflectance (Rs) 40.1% and Extinction ratio of above 16 for the visible light range.