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Design of Compact Common Mode Noise Absorption Filter (공통 모드 노이즈를 흡수하는 소형 공통 모드 필터 설계)

  • Jung, Hyeonjong;Jung, Jinwoo;Lim, Yeongseog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.12
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    • pp.963-968
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    • 2018
  • In this paper, a compact common mode filter using passive elements is designed and fabricated. To design a common mode filter with required frequency response, the equivalent circuits of the common mode filter in differential mode and common mode were analyzed. Compared with the former filter using a ${\lambda}/4$ resonator, the size of the proposed structure was reduced by 60 %. The fabricated common mode filter has a maximum differential mode insertion loss of 1.2 dB and a minimum common mode absorption efficiency of 78.2% in the CMA - bandwidth of 27.5 %.

한반도 지형에 적합한 SAR 위성의 운영모드 설계

  • Shin, Jae-Min;Im, Jeong-Heum;Kim, Eung-Hyun;Lee, Sang-Kon;Lee, Sang-Ryool
    • Aerospace Engineering and Technology
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    • v.3 no.2
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    • pp.34-41
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    • 2004
  • In this paper, the SAR operational mode for achieving mission is designed. Each mode, which is the strip mode, scan mode, and fine mode, is basically considered. Based on the characteristics, which includes incidence angle, of the topography in Korean Peninsula, look angle for SAR satellite is determined. The limited region of operating the mission, which is considered to be able to receive and transmit the radar data, was defined to use determined operational mode. In the future, as considering full requirements and conditions for the SAR satellite, requirements and parameters will be discussed and studied.

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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.

A Coding Mode Image Characteristics-based Fast Direct Mode Decision Algorithm (코딩 모드 영상 특성기반의 고속 직접모드 결정 알고리즘)

  • Choi, Yung-Ho;Han, Soo-Hee;Kim, Lark-Kyo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.8
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    • pp.1199-1203
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    • 2012
  • H.264 adopted many compression tools to increase image data compression efficiency such as B frame bi-directional predictions, the direct mode coding and so on. Despite its high compression efficiency, H.264 can suffer from its long coding time due to the complicated tools of H.264. To realize a high performance H.264, several fast algorithms were proposed. One of them is adaptive fast direct mode decision algorithm using mode and Lagrangian cost prediction for B frame in H.264/AVC (MLP) algorithm which can determine the direct coding mode for macroblocks without a complex mode decision process. However, in this algorithm, macroblocks not satisfying the conditions of the MLP algorithm are required to process the complex mode decision calculation, yet suffering a long coding time. To overcome the problem, this paper proposes a fast direct mode prediction algorithm. Simulation results show that the proposed algorithm can determine the direct mode coding without a complex mode decision process for 42% more macroblocks and, this algorithm can reduce coding time by up to 23%, compared with Jin's algorithm. This enables to encode B frames fast with a less quality degradation.

A hybrid algorithm based on EEMD and EMD for multi-mode signal processing

  • Lin, Jeng-Wen
    • Structural Engineering and Mechanics
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    • v.39 no.6
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    • pp.813-831
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    • 2011
  • This paper presents an efficient version of Hilbert-Huang transform for nonlinear non-stationary systems analyses. An ensemble empirical mode decomposition (EEMD) is introduced to alleviate the problem of mode mixing between intrinsic mode functions (IMFs) decomposed by EMD. Yet the problem has not been fully resolved when a signal of a similar scale resides in different IMF components. Instead of using a trial and error method to select the "best" outcome generated by EEMD, a hybrid algorithm based on EEMD and EMD is proposed for multi-mode signal processing. The developed approach comprises the steps from a bandpass filter design for regrouping modes of the IMFs obtained from EEMD, to the mode extraction using EMD, and to the assessment of each mode in the marginal spectrum. A simulated two-mode signal is tested to demonstrate the efficiency and robustness of the approach, showing average relative errors all equal to 1.46% for various noise levels added to the signal. The developed approach is also applied to a real bridge structure, showing more reliable results than the pure EMD. Discussions on the mode determination are offered to explain the connection between modegrouping form on the one hand, and mode-grouping performance on the other.

Fuzzy-sliding mode control of a full car semi-active suspension systems with MR dampers

  • Zheng, L.;Li, Y.N.;Baz, A.
    • Smart Structures and Systems
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    • v.5 no.3
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    • pp.261-277
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    • 2009
  • A fuzzy-sliding mode controller is presented to control the dynamics of semi-active suspension systems of vehicles using magneto-rheological (MR) fluid dampers. A full car model is used to design and evaluate the performance of the proposed semi-active controlled suspension system. Four mixed mode MR dampers are designed, manufactured, and integrated with four independent sliding mode controllers. The siding mode controller is designed to decrease the energy consumption and maintain robustness. In order to overcome the chattering of the sliding mode controllers, a fuzzy logic control strategy is merged into the sliding mode controller. The proposed fuzzy-sliding mode controller is designed and fabricated. The performance of the semi-active suspensions is evaluated in both the time and frequency domains. The obtained results demonstrate that the proposed fuzzy-sliding mode controller can effectively suppress the vibration of vehicles and improve their ride comfort and handling stability. Furthermore, it is shown that the "chattering" of the sliding mode controller is smoothed when it is integrated with a fuzzy logic control strategy. Although the cost function of the fuzzy-sliding mode control is a slightly higher than that of a classical LQR controller, the control effectiveness and robustness are enhanced considerably.

Operation Mode in Sequencing Batch Reactor for Nitrogen Removal (질소제거를 위한 연속회분식 반응조의 운전방식 연구)

  • Shin, Hang Sik;Kwon, Joong Chun;Koo, Ja Kong
    • Journal of The Korean Society of Civil Engineers
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    • v.8 no.2
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    • pp.77-88
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    • 1988
  • This research investigated the effect of COD/N ratio on nitrogen removal, and the use of organics in raw wastewater as a carbon source for denitrification in SBR(Sequencing Batch Reactor) systems. Four laboratory scale reactors were operated in three modes. Only the difference between modes were; Mode I operated in aerated condition during fill while Mode II in anoxic condition and Mode III operated on two fills per cycle in anoxic condition. When COD/N ratio increased, total nitrogen removal efficiencies increased from 8.7 to 57.7 percent in Mode I, from 28.9 to 83.2 percent in Mode II and from 42.7 to 97.8 percent in Mode III, respectively. COD removal efficiencies ranged from 93 to 98 percent throughout the study. SBR operation in Mode III of feeding twice per cycle in anoxic condition was an effective operating method for nitrogen removal and nitrogen concentration in effluent can be estimated using influent COD and nitrogen concentrations.

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Optimal Resource Allocation Scheme according to Access Mode in LTE Femtocell Systems (LTE 기반의 펨토셀 시스템에서 접근 모드에 따른 최적의 자원 할당 방식)

  • Lee, In-Sun;Park, Min-Ho;Kim, Dong-Ki;Hwang, Jae-Ho;Kim, Jae-Moung
    • Journal of Satellite, Information and Communications
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    • v.6 no.2
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    • pp.26-34
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    • 2011
  • In Femtocell that provides high quality of indoor communications with low transmitted power, there are two typical Access modes; Closed Access mode and Open Access mode. In this paper, we propose resource allocation scheme, which mitigates difference of performance between Access modes and improves overall cell performance, according to Access mode. We give more wireless resources to Open Access mode Femtocell, which improves performance of other users, than Closed Access mode Femtocell. If Open Access mode Femtocell uses more resource, there is trade-off between improvement of user using Open Access mode Femtocell and increase of interference that other users receive. So, we solve the optimal value for resource allocation and analyze performance of conventional scheme and proposed scheme applying the optimal value. Eventually, proposed scheme can improve overall cell performance relative to conventional scheme.

User Requirement Analysis of ECDIS for the Development on S-Mode Guideline (S-Mode 가이드라인 개발을 위한 ECDIS 사용자 요구사항 분석)

  • Jung, Min;Chae, Byeong-Geun;Ahn, Young-Joong
    • Journal of Navigation and Port Research
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    • v.40 no.3
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    • pp.89-95
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    • 2016
  • S-Mode is a concept involving a standardized navigation display with accompanying standardized functionality and interfaces for navigational equipment. It was proposed by the International Federation of Shipmasters' Associations at IMO NAV $54^{th}$ session in 2008. The IMO e-Navigation Strategy Implementation Plan(SIP) addresses, S-Mode and the IMO MSC at its $95^{th}$ session in 2015 approved an output 1 to develop S-Mode guidance. In this study, it has been carried out survey of user needs for adopting S-Mode guideline on ECDIS which is core navigational equipment. It is conducted with a questionnaire survey, targeting deck officers and masters who will be the primary users of the equipment related to the e-Navigation system. In this research, users' opinion survey regarding the necessity of development, the scope of standardization, and priorities was conducted. This survey result could be contributed to development S-Mode guideline and specify the concept of S-Mode. It would be derived from standardizing component through providing elements to be considered for its development.

Evaluation of Organ and Effective Dose using A PC-Based Monte Carlo Program in AEC Mode and Fix Mode for the whole spine antero-posterior radiography (전 척추 전.후 방향 검사 시 AEC Mode와 Fix Mode에서 PC-Based Monte Carlo Program을 이용한 장기선량 및 유효선량 평가)

  • Kim, Jeong Jin;Jang, Seong Won;Park, Jang Heum;Lee, Kwan Seob;Ha, Dong Yoon
    • Korean Journal of Digital Imaging in Medicine
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    • v.14 no.2
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    • pp.23-31
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    • 2012
  • There are AEC mode and fix mode to exposure when the whole spine antero-posterior radiography is done by using DR equipment. This study compared the utility of fix mode to AEC mode, by evaluating organ dose and effective dose and by examining the quality of radiographic image. GE DEFINIUM 8000 and ART-200X Rando Phantom manufactured by Flukebiometical were used for this study. The Rando phantom was set in front of wall detector of X-rays equipment. AEC mode was set at 80kVp and Fix mode was set at 80kVp, 25mAs, 32mAs, 40mAs, and 50mAs. Whole spine AP image were aquired by combining C, T-L and L-S spine images obtained through 3 exposures. When obtaining C, T-L and L-S spine images, were checked for Air kerma (mGy) value calculated by UNFORS Xi meter attached at the phantom surface of center of radiation field. The effective and organ doses were compared by PCXMC program (PC-Based Monte Carlo Program). The quality of obtained radiographic image was evaluated visually by 3 radiologists using resolution chart. When the effective doses was calculated based on tissue weighting factor of ICRP-103, 1.278mSv was measured by AEC mode, and Fix mode measured 0.405mSv at 25mAs, 0.518mSv at 32mAs, 0.649mSv at 40mAs, and 0.810mSv at 50mAS. In addition, the organ dose measured with esposure at 25mAs by Fix mode was almost equivalent to the organ dose by AEC mode, at the esophagus, thyroid, oral mucosa, salivaly glands located at the cervical spine part, while the organ dose by Fix mode was in general lower than the organ dose by AEC mode at the other organs. When Fix mode at 32mAs, 40mAs, and 50mAs was compared to AEC mode for organ dose in 26 organs, AEC mode had higher measurement in 21 organs but not for than brain, trachea, thyroid, oral mucosa, and salivaly glands which are located at the cervical spine part. The image quality evaluated by resolution test chart was much higher with AEC mode than the quality with Fix mode at all exposure conditions. However, while the image quality of cervical spine exposured at 50mAs by Fix mode was lower than the quality of AEC mode, thoraco-lumbar spine and lumbo-sacral spine were calculated and the quality was similar to AEC mode. Scoliosis occurs mainly at thoraco-lumbar and lumbo-sacral spine, not at cervical spine. Compared to AEC mode, Using the appropriate protocol (80kVp, 50mAs) of fix mode for whole spine AP radiography was thought to be useful because the image quality of the thoraco-lumar and lumbo-sacral spine was similar on AEC mode, Also organ and effective doses can be decreased with Fix mode. Therefore, It is considered that fix mode can be used properly with AEC mode for whole spine AP radiography when considering patient's body posture.

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