• ETRI Journal
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• 제45권4호
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• pp.650-665
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• 2023

A novel smart metering technique capable of anomaly detection was proposed for real-time home power management system. Smart meter data generated in real-time were obtained from 900 households of single apartments. To detect outliers and missing values in smart meter data, a deep learning model, the autoencoder, consisting of a graph convolutional network and bidirectional long short-term memory network, was applied to the smart metering technique. Power management based on the smart metering technique was executed by multi-objective optimization in the presence of a battery storage system and an electric vehicle. The results of the power management employing the proposed smart metering technique indicate a reduction in electricity cost and amount of power supplied by the grid compared to the results of power management without anomaly detection.

• 중소기업융합학회논문지
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• 제6권4호
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• pp.59-64
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• 2016

IETF에서 표준화한 6LoWPAN(IPv6 over Low Power Wireless Sensor Network)는 무선 센서 노드들의 이동성을 지원 하지 못한다. 무선 센서 노드가 CPU, 메모리, 배터리 사용에 있어 많은 제약을 받기 때문에 Mobile IPv6와 같은 기존의 프로토콜들을 적용하기 쉽지 않다. 본 논문에서는 이러한 센서 노드들의 이동성을 지원하기 위해 핸드오버 절차 수행을 호스트가 하지 않는 FPMIPv6(Fast PMIPv6)에 대한 기존 연구 분석을 바탕으로 6LoWPAN와 연동하는 새로운 이동성 관리 구조와 방안을 제안하였다. 연동을 위해 6LoWPAN에서 현재 사용되지 않는 dispatch code pattern의 사용을 제안하였으며, 핸드오버 과정에서 인증 지연으로 발생하는 패킷 손실을 줄이고 재전송으로 인해 발생하는 센서 노드의 전력 소모를 최소화하기 위해 MAG과 MAC, MAC와 AAA 사이에 임시 보증(temporary guarantee) 및 트러스트 관계(trust relationship)라는 새로운 개념을 도입하였다. 새롭게 제안된 인증절차와 구조는 인증 지연으로 인한 핸드오버 절단과 패킷 손실 및 재전송을 크게 줄일 것으로 예상된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.346-346
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• 2010

A capacitorless one transistor dynamic random access memory (1T-DRAM) on silicon-germanium-on-insulator substrate was investigated. SGOI technology can make high effective mobility because of lattice mismatch between the Si channel and the SiGe buffer layer. To evaluate memory characteristics of 1T-DRAM, the floating body effect is generated by impact ionization (II) and gate induced drain leakage (GIDL) current. Compared with use of impact ionization current, the use of GIDL current leads to low power consumption and larger sense margin.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.67-67
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• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, exhibits fascinating electrical properties, such as a linear energy dispersion relation and high mobility in addition to a wide-range optical absorption and high thermal conductivity. Graphene's outstanding tensile strength allows graphene-based electronic and photonic devices to be flexible, bendable, or even stretchable. Recently many groups have reported high performance electronic and optoelectronic devices based on graphene materials, i.e. field-effect transistors, gas sensors, nonvolatile memory devices, and plasmonic waveguides, in which versatile properties of graphene materials have been incorporated into a flexible electronic or optoelectronic platform. However, there are several fundamental or technological hurdles to be overcome in real applications of graphene in electronics and optoelectronics. In this tutorial we will present a short introduction to the basic material properties and recent progresses in applications of graphene to electronics and optoelectronics and discuss future outlook of graphene-based devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.95-96
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• 2009

A fully depleted capacitorless 1-transistor dynamic random access memory (FD 1T-DRAM) based on a sSOI strained-silicon-on-insulator) wafer was investigated. The fabricated device showed excellent electrical characteristics of transistor such as low leakage current, low subthreshold swing, large on/off current ratio, and high electron mobility. The FD sSOI 1T-DRAM can be operated as memory device by the floating body effect when the substrate bias of -15 V is applied, and the FD sSOI 1T-DRAM showed large sensing margin and several milli seconds data retention time.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.151-151
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• 2010

In this paper, the electrically properties of nonvolatile memory (NVM) using multi-stacks gate insulators of oxide-nitride-oxynitride (ONOn) and active layer of the low temperature polycrystalline silicon (LTPS) were investigated. From hydrogenated amorphous silicon (a-Si:H), the LTPS thin films with high crystalline fraction of 96% and low surface's roughness of 1.28 nm were fabricated by the metal induced crystallization (MIC) with annealing conditions of $650^{\circ}C$ for 5 hours on glass substrates. The LTPS thin film transistor (TFT) or the NVM obtains a field effect mobility of ($\mu_{FE}$) $10\;cm^2/V{\cdot}s$, threshold voltage ($V_{TH}$) of -3.5V. The results demonstrated that the NVM has a memory window of 1.6 V with a programming and erasing (P/E) voltage of -14 V and 14 V in 1 ms. Moreover, retention properties of the memory was determined exceed 80% after 10 years. Therefore, the LTPS fabricated by the MIC became a potential material for NVM application which employed for the system integration of the panel display.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.63-66
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• 1998

Prototype MFSFET′s using ferroelectric oxide LiNbO$_3$ as a gate insulator have been successfully fabricated with the help of 2 sheets of metal masks and demonstrated nonvolatile memory operations of the MFSFET′s. The estimated field-effect electron mobility and transconductance on a linear region of the fabricated FET were 600 $\textrm{cm}^2$/V.s and 0.16 mS/mm, respectively. The drain current of the "on" state was more than 4 orders of magnitude larger than the "off" state current at the same "read" gate voltage of 0.5 V, which means the memory operation of the MFSFET. A write voltage as low as $\pm$3 V, which is applicable to low power integrate circuits, was used for polarization reversal.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.396-396
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• 2013

The resistive random access memory (ReRAM) has several advantages to apply next generation non-volatile memory device, because of fast switching time, long retentions, and large memory windows. The high mobility of monolayered graphene showed several possibilities for scale down and electrical property enhancement of memory device. In this study, the monolayered graphene grown by chemical vapor deposition was transferred to $SiO_2$ (100 nm)/Si substrate and glass by using PMMA coating method. For formation of metal-oxide nanoparticles, we used a chemical reaction between metal films and polyamic acid layer. The 50-nm thick BPDA-PDA polyamic acid layer was coated on the graphene layer. Through soft baking at $125^{\circ}C$ or 30 min, solvent in polyimide layer was removed. Then, 5-nm-thick indium layer was deposited by using thermal evaporator at room temperature. And then, the second polyimide layer was coated on the indium thin film. After remove solvent and open bottom graphene layer, the samples were annealed at $400^{\circ}C$ or 1 hr by using furnace in $N_2$ ambient. The average diameter and density of nanoparticle were depending on annealing temperature and times. During annealing process, the metal and oxygen ions combined to create $In_2O_3$ nanoparticle in the polyimide layer. The electrical properties of $In_2O_3$ nanoparticle ReRAM such as current-voltage curve, operation speed and retention discussed for applictions of transparent and flexible hybrid ReRAM device.

• 대한전자공학회논문지SD
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• 제46권5호
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• pp.32-38
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• 2009

FFT(Fast Fourier Transform) 프로세서는 OFDM(Orthogonal Frequency Division Multiplexing) 시스템에서 사용된다. 근래에는 광대역과 이동성에 대한 요구가 높아짐에 따라 큰 포인트를 가지는 FFT 프로세서의 연구가 필요하다. FFT 포인트 수가 증가할수록 회전인자가 저장된 메모리가 차지하는 면적은 증가한다. 본 논문에서는 Radix-2, $2^2,\;2^3,\;2^4$ 알고리즘의 회전인자 인덱스 생성 방법을 제안한다. 제안한 회전인자 인덱스 생성기(Twiddle Factor Index Generator : TFIG)는 간단하게 카운터와 양수곱셈기로만 구성된다. 각각의 R2SDF(Radix-2 Single-Path Delay Feedback), $R2^2SDF,\;R2^3SDF,\;R2^4SDF$ 1024포인트 FFT 프로세서에 ROM 크기를 1/8N로 줄인 회전인자 계수 생성기(Twiddle Factor Coefficient Generator : TFCG)를 설계하여 제안한 알고리즘을 검증하였다. $R2^4SDF$의 TFCG 경우 면적, 전력에서 각 57.9%, 57.5%정도의 이득을 얻었다.

• 한국전자거래학회지
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• 제8권2호
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• pp.33-48
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• 2003

이동통신과 인터넷 기술의 결합으로 탄생한 무선 인터넷은 휴대의 편리성을 제공하고 있으나 모바일 환경의 제약사항 때문에 대중적인 인터넷 서비스로는 발전하지 못하고 있다. 무선 환경의 제한 요소 중 협소한 메모리 공간으로 모바일 디바이스에서는 효율적인 자원 관리를 수행하지 못하는 단점을 가지고 있다 휴대성이 고려되어야 하는 하드웨어 특성상 충분한 메모리 용량을 확보하는 데에는 한계가 있으므로 향후에는 디바이스 내부의 저장 장치에서 외부의 영역까지 메모리 공간을 확장하여 데이터 처리가 수행될 수 있는 플랫폼 구조로 발전되어야 할 것이다. 본 논문에서는 모바일 디바이스의 내부에서 외부의 서버까지 메모리 공간을 런타임 액세스(Run-time Access)에 의해서 확장하여 데이터 활용을 가능하게 하고 디바이스 내부의 파일을 효율적으로 관리할 수 있는 모바일 에이전트를 제안하며 이를 실현하기 위한 자원 관리시스템(RMS: Resources Management System)을 설계하고 구현하였다. 제안된 RMS를 적용한 디바이스는 '모바일 공간확장'으로 확대된 프로세스 적용이 가능하며 내부 파일을 효과적으로 관리하여 최적의 메모리 공간을 유지하는 효과가 있다.