• Title, Summary, Keyword: Multi-mode

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Analysis and simulation of multi-mode piezoelectric energy harvesters

  • Zhang, Ying;Zhu, Binghu
    • Smart Structures and Systems
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    • v.9 no.6
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    • pp.549-563
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    • 2012
  • Theoretical analysis is performed on a multi-mode energy harvester design with focus on the first two vibration modes. Based on the analysis, a modification is proposed for designing a novel adaptive multi-mode energy harvester. The device comprises a simply supported beam with distributed mass and piezoelectric elements, and an adaptive damper that provides a 180 degree phase shift for the motions of two supports only at the second vibration mode. Theoretical analysis and numerical simulations show that the new design can efficiently scavenge energy at the first two vibration modes. The energy harvesting capability of the multi-mode energy harvester is also compared with that of a cantilever-based energy harvester for single-mode vibration. The results show that the energy harvesting capacity is affected by the damping ratios of different designs. For fixed damping ratio and design dimensions, the multi-mode design has higher energy harvesting capacity than the cantilever-based design.

Comparison of Learning Effects using High-fidelity and Multi-mode Simulation: An Application of Emergency Care for a Patient with Cardiac Arrest (High-fidelity와 Multi-mode 시뮬레이션을 이용한 학습 효과 비교 : 심정지 환자 응급간호 적용)

  • Ryoo, Eon-Na;Ha, Eun-Ho;Cho, Jin-Young
    • Journal of Korean Academy of Nursing
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    • v.43 no.2
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    • pp.185-193
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    • 2013
  • Purpose: Simulation-based learning has become a powerful method to improve the quality of care and help students meet the challenges of increasingly complex clinical practice settings. The purpose of this study was to identify the learning effects using high-fidelity SimMan and multi-mode simulation. Methods: Participants in this study were 38 students who were enrolled in an intensive course for a major in nursing at R college. Collected data were analyzed using Chi-square, t-test, and independent t-test with the SPSS 18.0 for Windows Program. Results: There were no statistically significant differences in learning effects between high-fidelity SimMan and multi-mode simulation group. However, skills in clinical performance in the high-fidelity SimMan group were higher than in the multi-mode group (p=.014), communication in clinical performance in multi-mode simulation group was higher than in the high-fidelity SimMan group (p<.001). Conclusion: Multi-mode simulation with a standardized patient is an effective learning method in many ways compared to a high-fidelity simulator. These results suggest that multi-mode simulation be offered to students in nursing colleges which cannot afford to purchase a high-fidelity simulator, or offered as an alternative.

Security Architecture for T4 Class Common Data Link

  • Lee, Sang-Gon;Lee, Hoon-Jae;Kim, Hyeong-Rag;Ryu, Young-Jae
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.8
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    • pp.63-72
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    • 2017
  • In this paper, we propose a security architecture for HDLC-based T4 class common data link. The common data links are composed of point-to-point, multi-to-point, and point-to-multi mode. For multi-to-point mode, one node has a bundle of point-to-point links with different end-point on the other side of the links. Thus multi-to-point mode can be considered as a bundle of point-to-point mode. Point-to-multi mode is broadcasting link. For point-to-point mode we adopted robust security network scheme to establish a secure data link, and for multi-to-point mode we use broadcast encryption scheme based on ID-based cryptography to distribute encryption key for broadcasting message encryption. We also included MACsec technology for point-to-point data link security. Computational and communicational complexity analysis on the broadcast encryption have been done.

A Study on Stabilization of Multi-Excited Induction Motor (다중여자 유도전동기의 안정도에 관한 연구)

  • 강만원;김한성
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.9 no.4
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    • pp.78-85
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    • 1995
  • This paper covers stability and stabilization of Multi-Excited Induction Motor used in numberous electric equipment system of industrial field. The induction motor with multi-excitation has tow sets of three-phase system : One is connected to the AC source to supply most power required at the load, and the other is to the inverter for variable frequency and/or magnitude of voltage. The conventional induction motor is operated under single excitation mode only, that is called induction mode. But in multi-excited induction motor both the induction mode and the synchronous mode are possible, and the proposed multi-excited induction motor can be driven as a synchronous motor by the extra three-phase input. At the synchronous mode the efficiency is improved so higher than that at induction mode or conventional induction motor. The rating of the inverter used for speed control of numberous electric equipment system can be reduced upto one-tenth of that for conventional induction motor. Also the cost and maintenance fee of multi-excited induction motor can be reduced compared to any other motor.

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An Implementation of The Embedded-Based Multi Mode Receiver Module & Demuxer (임베디드용 멀티모드 방송 수신 모듈 및 역다중화기 설계 및 구현)

  • Kwon, KiWon;Kim, SeongJun;Park, SeHo;Park, YoungSuk;Hong, SukGun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.2
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    • pp.62-67
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    • 2011
  • In this paper, Multi Mode Receiver Module is designed in one H/W module for Multi-mode Digital Broadcasting. Multi mode means Digital TV, Mobile TV and Digital Radio on the Broadcasting. and T-DMB, DAB(+), ISDB-T and DVB-T standard. Our Module can receive various broadcasting signal such as ISDB-T, DVB-T and DAB. The Multi mode Receiver Module & demuxer was implemented using the one SoC Chip has good performances to receive the multi mode signals as well as standard interface such as SPI, to connect the main CPU Unit.

A Performance Comparison of the Partial Linearization Algorithm for the Multi-Mode Variable Demand Traffic Assignment Problem (다수단 가변수요 통행배정문제를 위한 부분선형화 알고리즘의 성능비교)

  • Park, Taehyung;Lee, Sangkeon
    • Journal of Korean Institute of Industrial Engineers
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    • v.39 no.4
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    • pp.253-259
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    • 2013
  • Investment scenarios in the transportation network design problem usually contain installation or expansion of multi-mode transportation links. When one applies the mode choice analysis and traffic assignment sequentially for each investment scenario, it is possible that the travel impedance used in the mode choice analysis is different from the user equilibrium cost of the traffic assignment step. Therefore, to estimate the travel impedance and mode choice accurately, one needs to develop a combined model for the mode choice and traffic assignment. In this paper, we derive the inverse demand and the excess demand functions for the multi-mode multinomial logit mode choice function and develop a combined model for the multi-mode variable demand traffic assignment problem. Using data from the regional O/D and network data provided by the KTDB, we compared the performance of the partial linearization algorithm with the Frank-Wolfe algorithm applied to the excess demand model and with the sequential heuristic procedures.

Effects of High-harmonic Components on the Rayleigh Indices in Multi-mode Thermo-acoustic Combustion Instability

  • Song, Chang Geun;Yoon, Jisu;Yoon, Youngbin;Kim, Young Jin;Lee, Min Chul
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.4
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    • pp.518-525
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    • 2016
  • This paper presents the characteristics of non-fundamental multi-mode combustion instability and the effects of high-harmonic components on the Rayleigh criterion. Phenomenological observations of multi-harmonic-mode dynamic pressure waves regarding the intensity of harmonic components and the source of wave distortion have been explained by introducing examples of second- and third-order harmonics at various amplitudes. The amplitude and order of the harmonic components distorted the wave shapes, including the peak and the amplitude, of the dynamic pressure and heat release, and consequently the temporal Rayleigh index and its integrals. A cause-and-effect analysis was used to identify the root causes of the phase delay and the amplification of the Rayleigh index. From this analysis, the skewness of the dynamic pressure turned out to be a major source in determining whether multi-mode instability is driving or damping, as well as in optimizing the combustor design, such as the mixing length and the combustor length, to avoid unstable regions. The results can be used to minimize errors in predicting combustion instability in cases of high multi-mode combustion instability. In the future, the amount of research and the number of applications will increase because new fuels, such as fast-burning syngases, are prone to generating multi-mode instabilities.

A System Operating Algorithm for the Effective Operation of a Multi-type Air-conditioning System (멀티형공조시스템의 효과적인 운전을 위한 시스템운전알고리즘)

  • Han Do-Young;Park Kwan-Jun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.7
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    • pp.587-595
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    • 2006
  • A system operating algorithm was developed for the effective operation of a multi-type air-conditioning system. The system operating algorithm includes control algorithms for a safety mode, an initial operating mode, a stabilization mode, a fault diagnosis mode, an efficiency mode, and a tracking mode. Various tests were performed to show the effectiveness of these algorithms. Tests showed good results for the operation of a multi-type air-conditioning system. Therefore, these algorithms developed for this study may be used for the effective control of a multi-type air-conditioning system.

Study of Hologram Multiplexing using Multi-mode Optical Fiber (다중모드 광섬유를 이용한 홀로그램 다중화 연구)

  • Kim, Soo-Gil
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.3
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    • pp.15-19
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    • 2004
  • We presented the holographic memory system using a multi-mode optical fiber. In this system, we multiplexed multiple holograms using the lights from multi-mode optical fibers as reference beams. The proposed system has two degrees of multiplexing freedom: speckle pattern of light coming from multi-mode fiber and spatial location of multi-mode fibers. Therefore, the data addressing in the system can be performed by mode and spatial multiplexings.

A Design of Wide Input Range Multi-mode Rectifier for Wireless Power Transfer System (넓은 입력 범위를 갖는 무선 전력 전송용 다중 모드 정류기 설계)

  • Choi, Young-Su;Lee, Kang-Yoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.49 no.4
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    • pp.34-42
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    • 2012
  • In this paper, a wide-input range CMOS multi-mode rectifier for wireless power transfer system is presented. The output voltage of multi-mode rectifier is sensed by comparator and switches are controlled based on it. The mode of multi-mode rectifier is automatically selected by the switches among full-wave rectifier, 1-stage voltage multiplier and 2-stage voltage multiplier. In full-wave rectifier mode, the rectified output DC voltage ranges from 9 V to 19 V for a input AC voltage from 10 V to 20 V. However, the input-range of the multi-mode rectifier is more improved than that of the conventional full-wave rectifier by 5V, so the rectified output DC voltage ranges from 7.5 V to 19 V for a input AC voltage from 5 V to 20 V. The power conversion efficiency of the multi-mode rectifier is 94 % in full-wave rectifier mode. The proposed multi-mode rectifier is fabricated in a $0.35{\mu}m$ CMOS process with an active area of $2500{\mu}m{\times}1750{\mu}m$.