• Title/Summary/Keyword: H Mode

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H.264의 FMO Performance Evaluation and Comparison over Packet-Lossy Networks (패킷 손실이 발생하는 네트워크 환경에서의 H.264의 FMO 성능분석과 비교에 관한 연구)

  • Kim Won-Jung;Lim Hye-Sook;Yim Chang-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.5C
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    • pp.490-496
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    • 2006
  • H.264 is the most recent video coding standard, containing improved error resilience tools than previous video compression schemes. This paper shows an analysis of the dependency of error concealment (EC) performance on the expected number of correctly received neighboring macroblock(MB)s for a lost MB, applying error concealment schemes to the raster scan mode that is used in the previous video coding standard and the flexible macroblock ordering (FMO) which is one of error-resilience tools in H.264. We also present simulation results and performance evaluation with various packet loss rates. Simulation results show that the FMO mode provides better EC performances of $1{\sim}9dB$ PSNR improvements compared to the raster scan mode because of larger expected number of correctly received neighboring MBs. The PSNR improvement by FMO mode becomes higher as the intra-frame period is larger and the packet loss rate is higher.

Study on characterization of hydrogenated carbon nitride thin films prebared by Plasma-Assisted Chemical Vapor Deposition (RF-PACVD를 이용한 Hydrogenated Carbon Nitride박막의 합성 및 특성에 관한 연구)

  • Lee, Chul-Hwa;Kim, Byoung-Soo;Park, Gu-Bum;Lee, Sang-Hee;Jin, Yoon-Young;Lee, Duck-Chool
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.856-857
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    • 1998
  • Hydrogenated amorphous carbon nitride [a-C:H(N)] films were deposited on pretreated silicon(100) substrate in activated gas phase using. RF plasma-assisted CVD. We measured the FT-IR spectrum to investigate $C{\equiv}N$ stretching mode(nitrile), C-H stretching mode, C-H bending mode, C=C stretching mode C=N(imino) mode, and the EDX to investigate the ratio of N to C(0.25). By the results of FT-IR and EDX spectrum, We confirmed that hydrogenated amorphous carbon nitride films successfully were synthesized by RF-PACVD

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E-H Mode Transition Properties of Cylindrical ICP Hg:Kr

  • Yang Jong-Kyung;Pack Kwang-Hyun;Lee Jong-Chan;Park Dae-Hee
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.3
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    • pp.124-130
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    • 2005
  • In this paper, we designed a cylindrical type light source having an electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the transformer principle, an electrically equivalent circuit cylindrical type light source was analyzed. According to the parameters of electromagnetic induction, which were diameter of coil with cpO.3$\~$ 1.2mm, number of turns with 4$\~$ 12 turns, distance with 40$\~$ l20mm and RF power with 10$\~$ 150W, the electrical .md optical properties were measured. When the diameter of the coil was cp0.3mm, number of turns was 8 and distance was 40mm, and the maximum brightness of 29,730 cd/m$^{2}$ was shown with RF power l50W. The relationship between electromagnetic induction and plasma discharges was demonstrated using the mode transition from E-mode to H-mode

Evaluation of the Image Backtrack-Based Fast Direct Mode Decision Algorithm

  • Choi, Yungho;Park, Neungsoo
    • Journal of Information Processing Systems
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    • v.8 no.4
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    • pp.685-692
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    • 2012
  • B frame bi-directional predictions and the DIRECT mode coding of the H.264 video compression standard necessitate a complex mode decision process, resulting in a long computation time. To make H.264 feasible, this paper proposes an image backtrack-based fast (IBFD) algorithm and evaluates the performances of two promising fast algorithms (i.e., AFDM and IBFD). Evaluation results show that an image backtrack-based fast (IBFD) algorithm can determine DIRECT mode macroblocks with 13% higher accuracy, as compared with the AFDM. Furthermore, IBFD is shown to reduce the motion estimation time of B frames by up to 23% with a negligible quality degradation.

A Study on carbon nitride thin films prepared by RF reactively sputtering (RF 반응성 스퍼터링에 의한 비정질 carbon nitride 박막의 제조에 관한 연구)

  • 이철화;김병수;이상희;진윤영;이덕출;박구범
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.406-408
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    • 1999
  • Amorphous carbon nitride thin films were prepared on pretreated silicon(100) substrate in sputtering graphite target by activated gas phase using RF reactively sputtering. We measured the FT-IR spectrum to identify C=N(nitrile)stretching mode(2200cm$\^$-1/), C-H stretching mode(2800cm$\^$-1/), C-H bending mode, C=C stretching mode C=N(imino) mode(1680cm$\^$-1/ ), and the XPS to investigate chemical structure of surface. By the results of FT-H and XPS spectrum, We confirmed that amorphous carbon nitride films with typel (C(1s): 285.9[eV], N(1s): 398.5[ev]) and type 2(C1s): 287.5[eV, N(1s): 400.2[eV]) successfully were synthesized by RF reactively sputtering

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Circular Dual Mode Horn Antenna(CDMHA) with Modified Aperture to Improve E/H-Plane Radiation Pattern Symmetry (E/H 평면 방사 패턴 대칭성 향상을 위해 개구면이 변형된 원형 이중 모드 혼 안테나)

  • Kim, Jae Sik;Yoon, Ji Hwan;Yoon, Young Joong;Lee, Woo-Sang;So, Joon-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.5
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    • pp.502-507
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    • 2013
  • In this paper, a circular dual mode horn with modified aperture is proposed to improve a E/H-plane radiation pattern symmetry of a conventional oversized circular dual mode horn. The proposed antenna consists of a feeding section, a mode generation section and a phase matching section which has aperture shape transition from circle to ellipse or rectangle to improve a E/H-plane radiation pattern symmetry. To compare the performances between the proposed antenna and the convenional circular dual mode horn, the conventional circular dual mode horn and the proposed circular dual mode horn with rectangular aperture are fabricated and researched at 15 GHz. The measured results show that the conventional circular dual mode horn has 3.394 dB difference while the proposed antenna has only 0.539 dB difference between E and H-plane radiation patterns within the -11 dB beamwidth($53^{\circ}$) which is required beamwidth of the feed horn for the maximum aperture efficiency where f/d ratio of reflector antenna is 1.

H.264/AVC Fast Macroblock Mode Decision Algorithm (H.264/AVC 고속 매크로블록 모드 결정 알고리즘)

  • Kim, Ji-Woong;Kim, Yong-Kwan
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.4 s.316
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    • pp.8-16
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    • 2007
  • For the improvement of coding efficiency, the H.264/AVC video coding standard employs new coding tools compared with existing coding standards. However, due to these new coding tools, the complexity of K264/AVC standard encoder is greatly increased. Specifically, the inter/intra mode decision method using RDO(rate-distortion optimization) technique is one of the most complex parts in H.264/AVC. In this paper, we focus on the complexity reduction in macroblock mode decision. In the proposed method, we reduce the complexity of the $4{\times}4$ mode decision process using $4{\times}4$ simple square filters, and using spatial block correlation method. Additionally, exploiting the best mode of sub_macroblock in $Inter8{\times}8$ mode, we proposed an algorithm to eliminate some intra modes in current macroblock mode decision process. In addition, we employed a method to raise the probability to select SKIP, $Intra16{\times}16$, and $Intra16{\times}16$ modes which usually show low complexity and low bitrate compared with other modes. From the simulation results, the proposed algorithm reduce the encoding time by maximum 83% of total, and reduce the bitrate of the overall sequences by $8{\sim}10%$ on the average compared with existing coding methods.

Temporal Directmode for B Picture in H.264 / MPEG-4 AVC (H.264 / MPEG-4 AVC에서의 B 픽쳐를 위한 시간적 다이렉트 모드)

  • 전병문
    • Journal of Broadcast Engineering
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    • v.7 no.4
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    • pp.300-309
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    • 2002
  • The object of this paper is to make temporal direct mode clear by providing a solution to the following problem : if the co-located block in the list 1 reference picture for direct mode has only the 1ist 1 motion vector or both the 1ist 0 and list 1 motion vectors, then which motion vector will be used for the direct mode motion vector calculation\ulcorner This paper also shows how to derive reference picture index and direct mode motion vector for each list in order to guarantee the high coding efficiency. when the co-located macroblock is in intra mode. Furthermore, the reasonable calculation methods for the direct mode motion vectors in the various cases are presented. Finally, experimental results show that the proposed temporal direct mode provides the comparable performance against the spatial direct mode. Therefore, the simulation proves that the proposed temporal direct mode is acceptable.

H-Plane Coupling Between Rectangular Microstrip antennas (구형 마이크로스트립 안테나의 H-Plane 상호결합)

  • Ko, Ji-Whan;Cho, Young-Ki;Son, Hyon
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.6
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    • pp.46-52
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    • 1985
  • A theoretical study of mutual coupling effects between two H-plane coupled microstrip patch antennas is presented. The radiation resistance and slot capacitance of a single micro-strip patch are calculated. To investigate the mutual coupling effects, the even and odd mode characteristic impedance and effective dielectric constants are obtained using the coupled microstrip line model. The S-parameter matrix elements 511,512 are used to study the mutual coupling e(facts in S-band frequency ranges for various patch spacings. Theoretical results and measurements are in good agreement.

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Investigation on Forced Vibration Behavior of Composite Main Wing Structure of A Small Scale WIG Craft Excited by Engine and Propeller (엔진 및 프로펠러에 의해 가진되는 소형 위그선 복합재 주날개의 진동 거동 해석)

  • Kong, Chang-Duck;Yoon, Jae-Huy;Park, Hyun-Bum
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.11
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    • pp.1028-1035
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    • 2007
  • this study, forced vibration analysis was performed on the composite main wing structure of a small scale WIG craft which is equipped two-stroke pusher type reciprocating engine. The structural vibration analysis based on the finite element method was performed using a commercial FEM code, MSC/NASTRAN. Excitations for the frequency response analysis were assumed as the H-mode(horizontal mode), the V-mode(vertical mode) and the X-mode(twisted mode) which are typical main vibration modes of engine. And excitations for the transient response analysis were assumed as the L-mode(longitudinal mode) with the oscillating propeller thrust which occurs.