• Title/Summary/Keyword: 2D direct mode

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Multi-View Video Coding Using Illumination Change-Adaptive Motion Estimation and 2D Direct Mode (조명변화에 적응적인 움직임 검색 기법과 2차원 다이렉트 모드를 사용한 다시점 비디오 부호화)

  • Lee, Yung Ki;Hur, Jae Ho;Lee, Yung Lyul
    • Journal of Broadcast Engineering
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    • v.10 no.3
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    • pp.321-327
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    • 2005
  • A MVC (Multi-view Video Coding) method, which uses both an illumination change-adaptive ME (Motion Estimation)/DC (Motion Compensation) and a 2D (Dimensional) direct mode, is proposed. Firstly, a new SAD (Sum of Absolute Difference) measure for ME/MC is proposed to compensate the Luma pixel value changes for spatio-temporal motion vector prediction. Illumination change-adaptive (ICA) ME/MC uses the new SAD to improve both MV (Motion Vector) accuracy and bit saving. Secondly, The proposed 2D direct mode that can be used in inter-view prediction is an extended version of the temporal direct mode in MPEG-4 AVC. The proposed MVC method obtains approximately 0.8dB PSNR (Peak Signal-to-Noise Ratio) increment compared with the MPEG-4 AVC simulcast coding.

Adaptive Spatio-Temporal Prediction for Multi-view Coding in 3D-Video (3차원 비디오 압축에서의 다시점 부호화를 위한 적응적 시공간적 예측 부호화)

  • 성우철;이영렬
    • Journal of Broadcast Engineering
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    • v.9 no.3
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    • pp.214-224
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    • 2004
  • In this paper, an adaptive spatio-temporal predictive coding based on the H.264 is proposed for 3D immersive media encoding, such as 3D image processing, 3DTV, and 3D videoconferencing. First, we propose a spatio-temporal predictive coding using the same view and inter-view images for the two TPPP, IBBP GOP (group of picture) structures 4hat are different from the conventional simulcast method. Second, an 2D inter-view direct mode for the efficient prediction is proposed when the proposed spatio-temporal prediction uses the IBBP structure. The 2D inter-view direct mode is applied when the temporal direct mode in B(hi-Predictive) picture of the H.264 refers to an inter-view image, since the current temporal direct mode in the H.264 standard could no: be applied to the inter-view image. The proposed method is compared to the conventional simulcast method in terms of PSNR (peak signal to noise ratio) for the various 3D test video sequences. The proposed method shows better PSNR results than the conventional simulcast mode.

A Sensitivity and Performance Analysis for Torque Mode Switching on 2MW Direct Drive Wind Turbine Generator (2MW급 직접구동형 풍력발전기의 풍황 민감도 및 토크모드 스위칭 성능 해석)

  • Rho, Joo-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.10
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    • pp.1455-1460
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    • 2014
  • Wind turbine generators were designed on general regulations of wind condition. At real situations, it could be different from the design conditions. There are many control methods and definitions of transient region, because an efficient wind turbine generator control logic is the important matter in generator performance and annual energy production at real conditions. In this document, the power generation sensitivity for wind speed and turbulence intensities was defined to know the sensitive transient region. Wind conditions are applied for the ranges of 7~10m/s mean wind speed and 14~20% turbulence intensity. The sensibility of HR-D86 wind generator was increased in transient region(8~10m/s) on power curve diagram through a torque control to a pitch control. And then GH-bladed simulations was performed for performance analysis of the torque mode switching in transient region on 2MW direct drive wind generator(HR-D86) which is designed IEC class II for onshore. Through the sensitivity and performance analysis, the sensitivity for real wind condition could be the performance index for an wind generator. And the torque mode switching in transient region can increase the mean power generation on HR-D86 wind turbine generator.

Direct and indirect methods for determination of mode I fracture toughness using PFC2D

  • Sarfarazi, Vahab;Haeri, Hadi;Shemirani, Alireza Bagher
    • Computers and Concrete
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    • v.20 no.1
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    • pp.39-47
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    • 2017
  • In this paper, mode I fracture toughness of rock was determined by direct and indirect methods using Particle Flow Code simulation. Direct methods are compaction tension (CT) test and hollow centre cracked quadratic sample (HCCQS). Indirect methods are notched Brazilian disk (NBD) specimen, the semi-circular bend (SCB) specimen, hollow centre cracked disc (HCCD), the single edge-notched round bar in bending (SENRBB) specimen and edge notched disk (END). It was determined that which one of indirect fracture toughness values is close to direct one. For this purpose, initially calibration of PFC was undertaken with respect to data obtained from Brazilian laboratory tests to ensure the conformity of the simulated numerical models response. Furthermore, the simulated models in five introduced indirect tests were cross checked with the results from direct tests. By using numerical testing, the failure process was visually observed. Discrete element simulations demonstrated that the macro fractures in models are caused by microscopic tensile breakages on large numbers of bonded discs. Mode I fracture toughness of rock in direct test was less than other tests results. Fracture toughness resulted from semi-circular bend specimen test was close to direct test results. Therefore semi-circular bend specimen can be a proper test for determination of Mode I fracture toughness of rock in absence of direct test.

Resource Allocation for Cooperative Relay based Wireless D2D Networks with Selfish Users

  • Niu, Jinxin;Guo, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.6
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    • pp.1996-2013
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    • 2015
  • This paper considers a scenario that more D2D users exist in the cell, they compete for cellular resources to increase their own data rates, which may cause transmission interference to cellular users (CU) and the unfairness of resource allocation. We design a resource allocation scheme for selfish D2D users assisted by cooperative relay technique which is used to further enhance the users' transmission rates, meanwhile guarantee the QoS requirement of the CUs. Two transmission modes are considered for D2D users: direct transmission mode and cooperative relay transmission mode, both of which reuses the cellular uplink frequency resources. To ensure the fairness of resource distribution, Nash bargaining theory is used to determine the transmission mode and solve the bandwidth allocation problem for D2D users choosing cooperative relay transmission mode, and coalition formation game theory is used to solve the uplink frequency sharing problem between D2D users and CUs through a new defined "Selfish order". Through theoretical analysis, we obtain the closed Nash bargaining solution under CUs' rate constraints, and prove the stability of the formatted coalition. Simulation results show that the proposed resource allocation approach achieves better performance on resource allocation fairness, with only little sacrifice on the system sum rates.

A 2.4-GHz Low-Power Direct-Conversion Transmitter Based on Current-Mode Operation (전류 모드 동작에 기반한 2.4GHz 저전력 직접 변환 송신기)

  • Choi, Joon-Woo;Lee, Hyung-Su;Choi, Chi-Hoon;Park, Sung-Kyung;Nam, Il-Ku
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.12
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    • pp.91-96
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    • 2011
  • In this paper, a low-power direct-conversion transmitter based on current-mode operation, which satisfies the IEEE 802.15.4 standard, is proposed and implemented in a $0.13{\mu}m$ CMOS technology. The proposed transmitter consists of DACs, LPFs, variable gain I/Q up-conversion mixer, a divide-by-two circuit with LO buffer, and a drive amplifier. By combining DAC, LPF, and variable gain I/Q up-conversion mixer with a simple current mirror configuration, the transmitter's power consumption is reduced and its linearity is improved. The drive amplifier is a cascode amplifier with gain controls and the 2.4GHz I/Q differential LO signals are generated by a divide-by-two current-mode-logic (CML) circuit with an external 4.8GHz input signal. The implemented transmitter has 30dB of gain control range, 0dBm of maximum transmit output power, 33dBc of local oscillator leakage, and 40dBc of the transmit third harmonic component. The transmitter dissipates 10.2mW from a 1.2V supply and the die area of the transmitter is $1.76mm{\times}1.26mm$.

0.18mm CMOS LNA/Mixer for UHF RFID Reader (UHF RFID 리더를 위한 0.18mm CMOS LNA/Mixer)

  • Woo, Jung-Hoon;Kim, Young-Sik
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.2
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    • pp.45-49
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    • 2009
  • In this paper, a direct down conversion LNA/Mixer has been designed and tested for 900Mhz UHF RFID application. The designed circuit has been implemented in 0.18um CMOS technology with 3.3V operation. In this work, a common gate input architecture has been used to cope with the higher input self jamming level. This LNA/Mixer is designed to support two operating modes of high gain mode and low gain mode according to the input jamming levels. The measured results show that the input referred P1dBs are 4dBm of high gain mode and 11dBm of low gain mode, and the conversion gains are 12dB and 3dB in high and low gain mode respectively The power consumptions are 60mW for high gain mode and 79mW for low gain mode. The noise figures are 16dB and 20dB in high gain mode and low gain mode respectively.

A 3~5 GHz UWB Up-Mixer Block Using 0.18-μm CMOS Technology

  • Kim, Chang-Wan
    • Journal of electromagnetic engineering and science
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    • v.8 no.3
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    • pp.91-95
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    • 2008
  • This paper presents a direct-conversion I/Q up-mixer block, which supports $3{\sim}5$ GHz ultra-wideband(UWB) applications. It consists of a VI converter, a double-balanced mixer, a RF amplifier, and a differential-to-single signal converter. To achieve wideband characteristics over $3{\sim}5$ GHz frequency range, the double-balanced mixer adopts a shunt-peaking load. The proposed RF amplifier can suppress unwanted common-mode input signals with high linearity. The proposed direct-conversion I/Q up-mixer block is implemented using $0.18-{\mu}m$ CMOS technology. The measured results for three channels show a power gain of $-2{\sim}-9$ dB with a gain flatness of 1dB, a maximum output power level of $-7{\sim}-14.5$ dBm, and a output return loss of more than - 8.8 dB. The current consumption of the fabricated chip is 25.2 mA from a 1.8 V power supply.

Clinical Application Analysis of 3D-CRT Methods Using Tomotherapy (토모테라피를 이용한 3차원 입체 조형 치료의 임상적 적용 분석)

  • Cho, Kang-Chul;Kim, Joo-Ho;Kim, Hun-Kyum;Ahn, Seung-Kwon;Lee, Sang-Kyoo;Yoon, Jong-Won;Cho, Jeong-Hee;Lee, Jong-Seok;Yoo, Beong-Gyu
    • Journal of radiological science and technology
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    • v.36 no.4
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    • pp.327-335
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    • 2013
  • This study investigates the case of clinical application for TomoDirect 3D-CRT(TD-3D) and TomoHelical 3D-CRT(TH-3D) with evaluating dose distribution for clinical application in each case. Treatment plans were created for 8 patients who had 3 dimensional conformal radiation therapy using TD-3D and TH-3D mode. Each patients were treated for sarcoma, CSI(craniospinal irradiaion), breast, brain, pancreas, spine metastasis, SVC syndrome and esophagus. DVH(dose volume histogram) and isodose curve were used for comparison of each treatment modality. TD-3D shows better dose distribution over the irradiation field without junction effect because TD-3D was not influenced by target length for sarcoma and CSI case. In breast case, dosimetric results of CTV, the average value of D 99%, D 95% were $49.2{\pm}0.4$ Gy, $49.9{\pm}0.4$ Gy and V 105%, V 110% were 0%, respectively. TH-3D with the dosimetric block decreased dose of normal organ in brain, pancreas, spine metastasis case. SCV syndrome also effectively decreased dose of normal organ by using dose block to the critical organs(spinal cord <38 Gy). TH-3D combined with other treatment modalities was possible to boost irradiation and was total dose was reduced to spinal cord in esophagus case(spinal cord <45 Gy, lung V 20 <20%). 3D-CRT using Tomotherapy could overcomes some dosimetric limitations, when we faced Conventional Linac based CRT and shows clinically proper dose distribution. In conclusion, 3D-CRT using Tomotherapy will be one of the effective 3D-CRT techniques.

Unified Chassis Control for Improvement of Vehicle Lateral Stability (차량 횡방향 안정성 향상을 위한 통합섀시 제어)

  • Cho, Wan-Ki;Yi, Kyoung-Su;Yoon, Jang-Yeol
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1126-1131
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    • 2007
  • This paper presents unified chassis control (UCC) to improve the vehicle lateral stability. The unified chassis control implies combined control of active front steering (AFS), electronic stability control (ESC) and continuous damping control (CDC). A direct yaw moment controller based on a 2-D bicycle model is designed by using sliding mode control law. A direct roll moment controller based on a 2-D roll model is designed. The computed direct yaw moment and the direct roll moment are generated by AFS, ESP and CDC control modules respectively. A control authority of the AFS and the ESC is determined by tire slip angle. Computer simulation is conducted to evaluate the proposed integrated chassis controller by using the Matlab, simulink and the validated vehicle simulator. From the simulation results, it is shown that the proposed unified chassis control can provide with improved performance over the modular chassis control.

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