• 제목/요약/키워드: Research laboratory

검색결과 16,299건 처리시간 0.043초

Measurement-Based Propagation Channel Characteristics for Millimeter-Wave 5G Giga Communication Systems

  • Lee, Juyul;Liang, Jinyi;Kim, Myung-Don;Park, Jae-Joon;Park, Bonghyuk;Chung, Hyun Kyu
    • ETRI Journal
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    • 제38권6호
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    • pp.1031-1041
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    • 2016
  • This paper presents millimeter-wave (mmWave) propagation characteristics and channel model parameters including path loss, delay, and angular properties based on 28 GHz and 38 GHz field measurement data. We conducted measurement campaigns in both outdoor and indoor at the best potential hotspots. In particular, the model parameters are compared to sub-6 GHz parameters, and system design issues are considered for mmWave 5G Giga communications. For path loss modeling, we derived parameters for both the close-in free space model and the alpha-beta-gamma model. For multipath models, we extracted delay and angular dispersion characteristics including clustering results.

Self-Assembled InAs Quantum Dots on InP(001) for Long-Wavelength Laser Applications

  • Kim, Jin-Soo;Lee, Jin-Hong;Hong, Sung-Ui;Kwack, Ho-Sang;Lee, Chul-Wook;Oh, Dae-Kon
    • ETRI Journal
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    • 제26권5호
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    • pp.475-480
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    • 2004
  • Self-assembled InAs quantum dots (QDs) embedded in an InAlGaAs matrix were grown on an InP (001) using a solid-source molecular beam epitaxy and investigated using transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. TEM images indicated that the QD formation was strongly dependent on the growth behaviors of group III elements during the deposition of InAlGaAs barriers. We achieved a lasing operation of around 1.5 ${\mu}m$ at room temperature from uncoated QD lasers based on the InAlGaAs-InAlAs material system on the InP (001). The lasing wavelengths of the ridge-waveguide QD lasers were also dependent upon the cavity lengths due mainly to the gain required for the lasing operation.

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RFID Tag Antenna Coupled by Shorted Microstrip Line for Metallic Surfaces

  • Choi, Won-Kyu;Kim, Jeong-Seok;Bae, Ji-Hoon;Choi, Gil-Young;Pyo, Cheol-Sig;Chae, Jong-Suk
    • ETRI Journal
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    • 제30권4호
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    • pp.597-599
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    • 2008
  • This letter presents the design of a small and low-profile RFID tag antenna in the UHF band that can be mounted on metallic objects. The designed tag antenna, which uses a ceramic material as a substrate, consists of a radiating patch and a microstrip line with two shorting pins for a proximity-coupled feeding structure. Using this structure, impedance matching can be simply obtained between the antenna and tag chip without a matching network. The fractional impedance bandwidth for $S_{11}$ <3 dB and radiation efficiency are about 1.4% and 56% at 911 MHz, respectively. The read range is approximately from 5 m to 6 m when the tag antenna is mounted on a metallic surface.

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InP-Based Polarization-Insensitive Planar Waveguide Concave Grating Demultiplexer with Flattened Spectral Response

  • Kwon, Oh-Kee;Lee, Chul-Wook;Lee, Dong-Hun;Sim, Eun-Deok;Kim, Jong-Hoi;Baek, Yong-Soon
    • ETRI Journal
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    • 제31권2호
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    • pp.228-230
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    • 2009
  • InP-based planar waveguide 48-channel concave grating demultiplexers with a channel spacing of 0.8 nm (100 GHz) are described and demonstrated. Polarization insensitivity and flattened spectral response are successfully achieved by the introduction of a polarization compensator and a two-focus grating, respectively. The fabricated device shows a polarization-dependent wavelength shift of less than 20 pm and a -3 dB spectral width of about 0.55 nm (68.75 GHz) over all channels.

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Enhanced Block-Based Adaptive Loop Filter with Multiple Symmetric Structures for Video Coding

  • Lee, Ha-Hyun;Lim, Sung-Chang;Choi, Hae-Chul;Jeong, Se-Yoon;Kim, Jong-Ho;Choi, Jin-Soo
    • ETRI Journal
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    • 제32권4호
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    • pp.626-629
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    • 2010
  • In this letter, we present an enhanced block-based adaptive loop filter (E-BALF) with multiple filter symmetric structures. The E-BALF adapts various filter symmetric structures in a rate-distortion optimization sense, reflecting the statistical properties of each image in a video sequence. Experimental results show that the proposed method achieves a reduction in the Bj${\phi}$ntegaard delta (BD)-bitrate by an average of 9.60% compared with Joint Model 11.0 of H.264/AVC. Compared to the state-of-the-art BALF, a reduction of up to 1.13% in BD-bitrate is achieved.

Geometry effect in the drug delivery for therapy with nanomedicines based on the conditions of the sport

  • Zhu, Lemei;Zou, Xuemin;Li, Xi;Zhang, Yuan;Liu, Juan;Xiang, Yuhan
    • Advances in nano research
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    • 제13권3호
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    • pp.217-231
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    • 2022
  • This study investigates the geometrical impact on the nanomedicine drug delivery via nanodevices. A nanomotor made of the nanotube carrying the drug as the motor blade is considered in the blood flow. Physical activities change the blood flow, and sports training enhances the blood flow and plays a significant role in the stability of drug delivery devices. This paper studies the impact of geometrical parameters on the nanomotors carrying the nanomedicine. The effect of physical exercise on the dynamic response regarding the stability of drug delivery devices is discussed in detail.

Inhibitory Activity of Diacylglycerol Acyltransferase by Tanshinones from the Root of Salvia miltiorrhiza

  • Ko, Jeong-Suk;Ryu, Shi-Young;Kim, Young-Sup;Chung, Mi-Yeon;Kang, Jong-Seong;Rho, Mun-Chual;Lee, Hyun-Sun;Kim, Young-Kook
    • Archives of Pharmacal Research
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    • 제25권4호
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    • pp.446-448
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    • 2002
  • The inhibitory activity of tanshinones from Salvia miltiorrhiza was tested on rat liver diacylglycerol acyltransferase (DGAT). Cryptotanshinone (1) and 15,16-dihydrotanshinone I (3) exhibited potent DGAT inhibitory activities dose-dependently with $IC_{50}$ values of $10.5 {\;}{\mu\textrm{g}}/ml{\;}and{\;}11.1{\;}{\mu\textrm{g}}/ml$. However, tanshinone IIA (2) and tanshinone I (4) showed very weak inhibition ($IC_{50}{\;}value:{\;}>{\;}250{\;}{\mu\textrm{g}}/ml$). A dihydrofuran moiety was seemed to be responsible for the stronger inhibitory activity

Tissue Microarrays in Biomedical Research

  • Chung, Joon-Yong;Kim, Nari;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Lee, Sang-Kyoung;Warda, Mohamad;Han, Jin
    • Bioinformatics and Biosystems
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    • 제1권1호
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    • pp.28-37
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    • 2006
  • Recent studies in molecular biology and proteomics have identified a significant number of novel diagnostic, prognostic, and therapeutic disease markers. However, validation of these markers in clinical specimens with traditional histopathological techniques involves low throughput and is time consuming and labor intensive. Tissue microarrays (TMAs) offer a means of combining tens to hundreds of specimens of tissue onto a single slide for simultaneous analysis. This capability is particularly pertinent in the field of cancer for target verification of data obtained from cDNA micro arrays and protein expression profiling of tissues, as well as in epidemiology-based investigations using histochemical/immunohistochemical staining or in situ hybridization. In combination with automated image analysis, TMA technology can be used in the global cellular network analysis of tissues. In particular, this potential has generated much excitement in cardiovascular disease research. The following review discusses recent advances in the construction and application of TMAs and the opportunity for developing novel, highly sensitive diagnostic tools for the early detection of cardiovascular disease.

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Production of Human Keratinocyte 14 Promoter Driven EC-SOD Transgenic Mice

  • Kim, Sung-Hyun;Lee, Tae-Hoon;Kim, Kil-Soo;Lee, Eun-Ju;Kim, Myoung-Ok;Park, Jun-Hong;Cho, Kyoung-In;Jung, Boo-Kyung;Kim, Hee-Chul;Hwang, Sol-Ha;Lee, Hoon-Taek;Ryoo, Zae-Young
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.222-222
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    • 2004
  • Superoxide dismutases are key antioxidant enzymes in metabolism of reactive oxygen species. Three different isoforms of SOD exist in mammals. The extracellular SOD (EC-SOD) is the most recently discovered SOD family member. This isoform is a copper- and zinc-containing enzyme like Cu/Zn-SOD and a homotetrameric glycoprotein with a molecular weight of about 165 kDa in mouse. (omitted)

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