• Title/Summary/Keyword: transient information

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Design and Performance Analysis of a Noncoherent Code Tracking Loop for 3GPP MODEM (3GPP 모뎀용 동기 추적회로의 설계 및 성능 분석)

  • 양연실;박형래
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.12A
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    • pp.983-990
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    • 2003
  • In this paper, a noncoherent code tracking loop is designed for 3GPP MODEM and its performance is analyzed in terms of steady-state jitter variance and transient response characteristics. An analytical closed-form formula for steady-state jitter variance is Int derived for AWGN environments as a general function of a pulse-shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth, together with the analysis on the transient response characteristic of a tracking loop. Based on the analysis, the code tracking loop with variable loop bandwidth that is efficient for full digital H/W implementation is designed and its performance is compared with that of the code tracking loop with fixed loop bandwidth, along with the verification by computer simulations.

DTV Lip-Sync Test Using Embedded Audio-Video Time Indexed Signals (숨겨진 오디오 비디오 시간 인덱스 신호를 사용한 DTV 립싱크 테스트)

  • 한찬호;송규익
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.3
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    • pp.155-162
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    • 2004
  • This paper concentrated on lip synchronization (lip sync) test for DTV with respect to audio and video signals using a finite digital bitstream In this paper, we propose a new lip sync test method which does not effect on the current program by use of the transient effect area test signals (TATS) and audio-video time index lip sync test signals (TILS).the experimental result shows that the time difference between audio and video signal can be easily measured by captured oscilloscope waveform at any time.

Transient Analysis of Conducting Wire Antennas Using Laguerre Polynomials (라게르 함수를 이용한 도선 안테나의 과도해석)

  • Kim, Hyung-Jin;Kim, Chung-Soo;Park, Jae-Kwon;Jung, Baek-Ho
    • Proceedings of the KIEE Conference
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    • 2003.10a
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    • pp.266-269
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    • 2003
  • In this work, a new formulation is presented for analyzing the transient electromagnetic response from wire antennas using the time-domain integral equation. The solution method is based on the Galerkin's method that involves separate spatial and temporal testing procedures. Piecewise triangle basis functions have been used for spatial expansion functions for arbitrarily shaped wire structures. The time-domain variation is approximated by a set of orthonormal basis functions that are derived from the Laguerre polynomials. The method presented in this paper results in very stable transient responses from wire antennas.

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2-Dimensional FEM Based Transient Analysis for an Efficient Design of Acoustic Windows (효율적인 음향 윈도우 설계를 위한 2차원 유한요소법 기반의 과도 해석)

  • Kim, Y.C.;Kim, S.K.;Yoon, S.W.;Lee, Y.;Cho, M.S.;Shin, Ku-Kyun;Koo, J.C.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.7
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    • pp.673-678
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    • 2009
  • The efficiency of active sonar that is used underwater observation equipment is important for obtain the information of topography and trace for the objects. Sound wave transmitted from sonar are distorted by acoustic window which is to protect sonar. Making various sonar dome is impossible for experiment, because consumed unnecessary time and expense. So, the purpose of this study is to simulate and analyze the acoustic window propagated sound wave from sonar for designing model reduced insertion loss. Simulation is performed by transient analysis and fluid-structure interaction analysis. As a result, this study will give a opportunity for efficient design of sonar dome without high cost and time consumption.

Theoretical Analysis of Fast Gain-Transient Recovery of EDFAs Adopting a Disturbance Observer with PiD Controller in WDM Network

  • Kim, Sung-Chul;Shin, Seo-Yong;Song, Sung-Ho
    • Journal of the Optical Society of Korea
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    • v.11 no.4
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    • pp.153-157
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    • 2007
  • We have proposed an application of disturbance observer with PID controller to minimize gain-transient time of wavelength-division-multiplexing(WDM) multi channels in optical amplifier in channel add/drop networks. We have dramatically reduced the gain-transient time to less than $3{\mu}sec$ by applying a disturbance observer with a proportional/integral/ differential(PID) controller to the control of amplifier gain. The theoretical analysis on the 3-level erbium-doped fiber laser and the disturbance observer technique is demonstrated by performing the simulation with co-simulation of the $MATLAB^{TM}$ and a numerical modeling software package such as the $Optsim^{TM}$.

Optimization of Transient Stability Control Part-I: For Cases with Identical Unstable Modes

  • Xue Yusheng;Li Wei;Hill David John
    • International Journal of Control, Automation, and Systems
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    • v.3 no.spc2
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    • pp.334-340
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    • 2005
  • Based on the stability margin provided by the EEAC, the unstable contingencies can be classified into sets according to their unstable modes. This two-part paper develops a globally optimal algorithm for transient stability control to coordinate preventive actions and emergency actions. In the first part, an algorithm is proposed for a set of contingencies having identical unstable modes. Instead of iterations between discrete emergency actions and continuous preventive actions, the algorithm straightforwardly searches for a globally optimal solution. The procedure includes assessing a set of insufficient emergency schemes identified by the EEAC; calculating the related preventive actions needed for stabilizing the system; and selecting the scheme with the minimum overall costs. Simulations on a Chinese power system highlight its excellent performance. The positive results obtained are explained by analogizing settlements for 0-1 knapsack problems using the multi-points greedy algorithm.

Optimization of Transient Stability Control Part-II: For Cases with Different Unstable Modes

  • Xue Yusheng;Li Wei;Hill David John
    • International Journal of Control, Automation, and Systems
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    • v.3 no.spc2
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    • pp.341-345
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    • 2005
  • Part-I of this two-part paper develops an optimal algorithm for transient stability control to coordinate the preventive actions and emergency actions for a subset of contingencies with an identical unstable mode. In this portion, several subsets of contingencies having dissimilar unstable modes are dealt with. Preventive actions benefiting a subset of contingencies may go against the stability of others, thus coordination among the optimal schemes for individual subsets is necessary. The coordination can be achieved by replacing some preventive actions with contingency-specified emergency actions. It is formulated as a classical model of economic dispatch with stability constraints and stability control costs. Such an optimal algorithm is proposed based on the algorithm in Part-I of the paper and is verified by simulations on a Chinese power system.

Dynamic Transient Phenomena of Proton Exchange Membrane Fuel Cell

  • Lee, Ying;Choi, Yong-Sung;Zhang, You-Sai;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.9-9
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    • 2010
  • The proton exchange membrane fuel cell (PEMFC) holds great promise of clean power. However, in practical applications which use the PEMFC as the power source, the output voltage from the fuel cell undergoes transient response especially during acceleration and deceleration. This paper presents the relationships between the internal voltage drop, voltage of time constant, time constant of FC1 and FC2 (in series and in parallel) charge curves and discharge curves respectively.

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Effect of the size of active device and heatsink of power MOSFETs on its the junction to ambient transient thermal behavior

  • Koh, Jeong-Wook;An, Chul
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.241-244
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    • 2000
  • To investigate the compact effect of the different area of an active layer and the different type of heatsink on the junction to ambient transient thermal impedance, we have characterized the thermal behavior of power MOSFETs that have three different areas of an active layer and two types of heatsink. To do so, the "cooling curve method" has been used in order to measure the junction-to-ambient transient thermal impedance Zthja that represents the thermal behavior of the devices. The measured data depiets that the larger area of an active layer gives the better-in other words. smaller-thermal impedance, and that the larger size of a heatsink improves the thermal impedance.

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