• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.375-384
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• 2007

This paper describes a method for automatic acquisition of wide-coverage treebank-based deep linguistic resources for Japanese, as part of a project on treebank-based induction of multilingual resources in the framework of Lexical-Functional Grammar (LFG). We automatically annotate LFG f-structure functional equations (i.e. labelled dependencies) to the Kyoto Text Corpus version 4.0 (KTC4) (Kurohashi and Nagao 1997) and the output of of Kurohashi-Nagao Parser (KNP) (Kurohashi and Nagao 1998), a dependency parser for Japanese. The original KTC4 and KNP provide unlabelled dependencies. Our method also includes zero pronoun identification. The performance of the f-structure annotation algorithm with zero-pronoun identification for KTC4 is evaluated against a manually-corrected Gold Standard of 500 sentences randomly chosen from KTC4 and results in a pred-only dependency f-score of 94.72%. The parsing experiments on KNP output yield a pred-only dependency f-score of 82.08%.

• Structural Engineering and Mechanics
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• 제31권5호
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• pp.527-544
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• 2009

In this study, the periodic seismic performance evaluation scheme is proposed using a structural health monitoring system in terms of seismic fragility. An instrumented highway bridge is used to demonstrate the evaluation procedure involving (1) measuring ambient vibration of a bridge under general vehicle loadings, (2) identifying modal parameters from the measured acceleration data by applying output-only modal identification method, (3) updating a preliminary finite element model (obtained from structural design drawings) with the identified modal parameters using real-coded genetic algorithm, (4) analyzing nonlinear response time histories of the structure under earthquake excitations, and finally (5) developing fragility curves represented by a log-normal distribution function using maximum likelihood estimation. It is found that the seismic fragility of a highway bridge can be updated using extracted modal parameters and can also be monitored further by utilizing the instrumented structural health monitoring system.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.43-48
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• 2007

In this study, an ANN-based damage detection algorithm using acceleration signals is developed for alarming locations of damage in beam-type structures. A new ANN-algorithm using output-only acceleration responses is designed for damage detection in real time. The cross-covariance of two acceleration signals measured at two different locations is selected as the feature representing the structural condition. Neural networks are trained for potential loading patterns and damage scenarios of the target structure for which its actual loadings are unknown. The feasibility and practicality of the proposed method are evaluated from laboratory-model tests on free-free beams for which accelerations were measured before and after several damage cases.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.275-276
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• 2013

In this paper, we proposed the Z-source four-switch three-phase rectifier. As we know, the conventional Four-Switch Three-Phase Rectifier(FSTPR) has advantages of the lower cost and less complex switching control. However, The conventional FSTPR can only either perform buck or boost operation, it can only attain the buck-boost operation by adding another DC-DC converter. In addition, besides its narrow output voltage region, distortion of the input current is serious either. Thus, we proposed the Z-source FSTPR which has buck-boost function and better input current waveform by applying the Z-impedance network to the conventional FSTPR. The validity of the proposed system was confirmed by experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.496-498
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• 1998

This paper presents a mathod of reducing hunting size or steady state error occurred in the output signals via regulating the PID controllers gains. The PID controllers are widely used in industrial processes. Such processes have several inherent features like continuous operation, fixed set value, and difficulty in applyirty test signals. Thus, this paper suggests fuzzy rules of reducing hunting magnitude or steady state error using output signals only. Such an intelligent tuning technique utilizes both the experts, experience and control engineers' theortical background. For two kinds of systems such as temperature or DC motors speed control, we showed the validity of proposed method in this paper.

• Structural Engineering and Mechanics
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• 제56권3호
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• pp.423-442
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• 2015

This study examines the wavelet transform for output-only system identification of ambient excited engineering structures with emphasis on its utilization for modal parameter estimation of high-order and closely-spaced modes. Sophisticated time-frequency resolution analysis has been carried out by employing the modified complex Morlet wavelet function for better adaption and flexibility of the time-frequency resolution to extract two closely-spaced frequencies. Furthermore, bandwidth refinement techniques such as a bandwidth resolution adaptation, a broadband filtering technique and a narrowband filtering one have been proposed in the study for the special treatments of high-order and closely-spaced modal parameter estimation. Ambient responses of a 5-story steel frame building have been used in the numerical example, using the proposed bandwidth refinement techniques, for estimating the modal parameters of the high-order and closely-spaced modes. The first five natural frequencies and damping ratios of the structure have been estimated; furthermore, the comparison among the various proposed bandwidth refinement techniques has also been examined.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.44-49
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• 2003

This paper describes a percentage current differential relaying algorithm for bus protection blocked by a CT saturation detection algorithm. The detection algorithm blocks the output of a current differential relay only if a differential current is caused by CT saturation in the case of an external fault. Moreover, if a current differential relay operates faster than the detection algorithm, the blocking signal is not ignited. On the other hand. if the detection algorithm operates faster than a current differential relay, the output of the relay is blocked. The results of the simulation show that the proposed algorithm can discriminate internal faults from external faults ever when a CT is saturated in both cases. This paper concludes by implementing the algorithm into the TMS320C6701 digital signal processor. The results of hardware implementation are also satisfactory The algorithm can not only increase the sensitivity of the current differential relay but Improve the stability of the relay for an external faults.

• 대한전기학회논문지
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• 제41권6호
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• pp.615-624
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• 1992

For the operation of the resonant DC link inverters, only limited number of modulation techniques such as the delta modulation and instantaneous current control techniques have been suggested. However, these modulation techniques have some limitations in practical operation. In this paper, the application of conventional inverter modulation techniques is suggested for the control of the resonant DC link inverter. The harmonic analysis results are presented. The results show that these modulation techniques offer good output characteristics similar to conventional inverter PWM techniques for the operation of the resonant DC link inverter. This implies that not only the delta modulation technique and instantaneous current control techniques but also various other modulation techniques can be applied to the operation of the resonant DC link inverter. This also indicates that open loop control as well as closed loop control can be used for the operation of the resonant inverter. The resonant DC link inverter with various modulation strategies is implemented using V-40 microprocessors.

• 드라이브 ㆍ 컨트롤
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• 제14권4호
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• pp.61-70
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• 2017

In this study, an extended-state-observer (ESO) based non-linear servo control is introduced for an electro-hydrostatic actuator (EHA). Almost hydraulic systems not only are highly non-linear system that has mismatched uncertainties and external disturbances, but also can not measure some states. ESO that only use an output signal can be used to compensate these uncertainties and estimate unmeasurable states. To improve the position tracking performance, the barrier Lyapunov function (BLF) that can guarantee an output tolerance is introduced for the position tracking error signal of back stepping control procedures. Finally, the proposed servo control is compared with the proportional-integral (PI) control.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.369-378
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• 2021

This paper reviewed a few output-only system identification algorithms and identified the shortcomings of those popular blind source separation methods. To address the issues such as less sensors than the targeted modal modes (under-determinate problem), repeated natural frequencies as well as systems with complex mode shapes, this paper proposed a complex wavelet modified second order blind identification method (CWMSOBI) by transforming the time domain problem into time-frequency domain. The wavelet coefficients with different dominant frequencies can be used to address the under-determinate problem, while complex mode shapes are addressed by introducing the complex wavelet transformation. Numerical simulations with both high and low signal-to-noise ratios validate that CWMSOBI can overcome the above-mentioned issues while obtaining more accurate identified results than other blind identification methods.