• The Journal of the Acoustical Society of Korea
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• v.20 no.5
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• pp.48-53
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• 2001

In speaker verification based on LPC analysis the prediction residues are ignored and LPCC(LPC cepstrum) are only used to compose feature vectors. In this study, LPCC and RCEP (residual cepstrum) extracted from residues are used as feature parameters in the various environmental speaker verification. We propose the weighting function which can enlarge inter-speaker variation by weighting pitch, speaker inherent vector, included in residual cepstrum. Simulation results show that the average speaker verification rate is improved in the rate of 6％ with RCEP and LPCC at the same time and is improved in the rate of 2.45% with the proposed weighted RCEP and LPCC at the same time compared with no weighting.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.646-653
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• 2005

This paper proposes that wavelength assignment algorithm maximizes residual links considering more real wavelength conversion in the WDM network. The existing algorithms are inefficient that they ignore wavelength conversion ability in each nodes and fixed uniformly wavelength conversion ability on all nodes. Proposed method makes a ring shape that maximize available residual links considering wavelength conversion ability in each nodes. Maximizing residual links can assign a wavelength for any path require. Then blocking probability is reduced by the maximum 19 percent and wavelength conversion number is improved by about 40 percent. These can be showed in performance evaluation.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.113-117
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• 2011

The frame for automotive assembly can be deformed and remained on the residual stress due to high temperature thermal attacks when in welding. The frame deformation can be made to problems when in assembly with body and the residual stress can affect the negative effect on durability performance of the automobile. In order to analyze the frame deformation, the simplified test frame which had the similar shape (form) of the real automotive frame was fabricated. The contactless optical 3D scanner was used for the shape difference measurement of the frame between before and after the welding. The FE-model of the test frame was composed and the heat transfer and thermal stress simulation were performed. The simulated results were compared with the measured results for the reference of the frame design. The deformation shape of the frame by simulation was in good agreement with that by the experimental measurement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.9
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• pp.862-867
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• 2006

Bi-based nano-varistors and micro-varistors fabricated with each ZnO nano-powder and micro-powder were studied about characteristics on the surge capability in this study. ZnO nano-varistors were sintered in air at $1050^{\circ}C$ for 2 hr. The voltage-current and residual voltage properties of ZnO nano-varistor were compared with their of ZnO micrio-varistor. As a result of these properties, our ZnO nano-varistor has about 3 times at operating voltage as compared with conventional ZnO varistor fabricated with micro-powder and the residual voltage was 8.06 kV at nominal discharge current 101kA in the lighting impulse current test. And then the residual voltage rate 1.72 of our nano-varistor has had better performance than the 1.79 of micro-varistor because ZnO nano-varistor has shown much quick response property because of increasing effective cross-section area. Also, to analysis surge capability took thermal images for pyrexia temperature distribution with each of the varistors after operating varistors. Nano-varistor doesn't have shown local overheating and can confirm accurate temperature grade on the surface of its.

• Earthquakes and Structures
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• v.8 no.6
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• pp.1277-1297
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• 2015

Post-tensioned precast segmental bridge columns have shown high level of strength and ductility, and low residual displacement, which makes them suffer minor damage after earthquake loading; however, there is still lack of confidence on their lateral response against severe seismic loading due in part to their low energy dissipation capacity. This study investigates the influence of major design factors such as post-tensioning force level, strands position, columns aspect ratio, steel jacket and mild steel ratio on seismic performance of self-centring segmental bridge columns in terms of lateral strength, residual displacement and lateral peak displacement. Seismic analyses show that increasing the continuous mild steel ratio improves the lateral peak displacement of the self-centring columns at different levels of post-tensioning (PT) forces. Such an increase in steel ratio reduces the residual drift in segmental columns with higher aspect ratio more considerably. Suggestions are proposed for the design of self-centring segmental columns with various aspect ratios at different target drifts.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.198-208
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• 2001

In this paper, vibration suppression of an elastic beam fixed on a moving cart and carrying a fixed or moving mass is considered. A modified pulse sequence method with RIC(Robust Internal-loop Compensator) is proposed to suppress the single model residual vibration and to get accurate positioning of the beam-mass-cart system. The performance of the proposed input preshaping method is compared with that of the previous ones through simulations and experiments. Using the proposed method, it is able to suppress the initial vibration of the beam-mass-cart system carrying a concentrated mass. Accurate PTP(point-to-point) positioning of the moving mass without residual vibration is also obtained experimentally by modifying the proposed pulse sequence method. Finally, the proposed input preshaping method is applied successfully to the system to follow square trajectories of the moving mass without residual vibration.

• Steel and Composite Structures
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• v.33 no.5
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• pp.641-652
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• 2019

This paper investigates the effect of aftershocks on the seismic performance of self-centering (SC) prestressed concrete frames using the probabilistic seismic demand analysis methodology. For this purpose, a 4-story SC concrete frame and a conventional reinforced concrete (RC) frame are designed and numerically analyzed through nonlinear dynamic analyses based on a set of as-recorded mainshock-aftershock seismic sequences. The peak and residual story drifts are selected as the demand parameters. The probabilistic seismic demand models of the SC and RC frames are compared, and the SC frame is found to have less dispersion of peak and residual story drifts. The results of drift demand hazard analyses reveal that the SC frame experiences lower peak story drift hazards and significantly reduced residual story drift hazards than the RC frame when subjected to the mainshocks only or the mainshock-aftershock sequences, which demonstrates the advantages of the SC frame over the RC frame. For both the SC and RC frames, the influence of as-recorded aftershocks on the drift demand hazards is small. It is shown that artificial aftershocks can produce notably increased drift demand hazards of the RC frame, while the incremental effect of artificial aftershocks on the drift demand hazards of the SC frame is much smaller. It is also found that aftershock polarity does not influence the drift demand hazards of both the SC and RC frames.

• Journal of information and communication convergence engineering
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• v.11 no.1
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• pp.1-6
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• 2013

Suppressing or mitigating signal distortion due to group velocity dispersion and optical Kerr effects is necessary in ultra-high speed and long-haul wavelength division multiplexing (WDM) transmission systems. Dispersion management (DM), optical phase conjugation (OPC), and the combination of these two are promising techniques to compensate for signal distortion. In this paper, to implement a flexible optical WDM network, a new optical link configuration with a randomly distributed single-mode fiber (SMF) length and fixed residual dispersion per span in the combination of DM and OPC is proposed and investigated. The simulation results show that the best net residual dispersion (NRD) in the proposed optical links is +10 ps/nm, which is independent of pre- and postcompensation. The effective launch power of the WDM channel is increased more in the optical links with NRD = +10 ps/nm controlled by only precompensation. Furthermore, the system performance difference between the proposed optical link configuration with the best NRD and the conventional optical link with uniform distribution of the SMF length had little significance. Consequently, it is confirmed that the proposed optical link configuration with the best NRD is effective and useful for implementing a reconfigurable long-haul WDM network.

• KSTLE International Journal
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• v.6 no.2
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• pp.45-50
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• 2005

Plasma ceramic spray that is applied on a machine part under severe work conditions has been investigated for tribological behavior. The application of ceramic coatings by plasma spray has become essential in tribosystems to produce wear resistance and long life in severe conditions. The purpose of this study was to investigate the wear characteristics of $8\%Y_{2}O_3-ZrO_2$ coating, in view of the effect of post-spay heat treatment. The plasma-sprayed $8\%Y_{2}O_3-ZrO_2$ coating was studied to know the relationship between phase transformations and wear behavior related to post-spray heat treatment. Wear test was carried out with ball on disk type on normal loads of 50N,70N and 90N under room temperature. The phase transformation of phase and the value of residual stress were measured by X-ray diffraction method(XRD). Tribological characteristics and wear mechanisms of coatings were observed by SEM. The tribological wear performance was discussed in the focusing of residual stress. Consequently, post-spray heat treatment plays an important role in decreasing residual stress. Residual stress in the coating system has a significant influence on the wear mechanism of coating.

• Structural Engineering and Mechanics
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• v.71 no.6
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• pp.683-697
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• 2019

The reinforced concrete (RC) structures usually suffer large residual displacements under strong motions. The large residual displacements may substantially reduce the anti-seismic capacity of structures during the aftershock and increase the difficulty and cost of structural repair after an earthquake. To reduce the adverse residual displacement, several self-centering energy dissipation braces (SCEBs) have been proposed to be installed to the RC structures. To investigate the seismic responses of the RC structures with SCEBs under the earthquake excitation, an extended Bouc-Wen model with degradation and self-centering effects is developed in this study. The extended model realized by MATLAB/Simulink program is able to capture the hysteretic characteristics of the RC structures with SCEBs, such as the energy dissipation and the degradation, especially the self-centering effect. The predicted hysteretic behavior of the RC structures with SCEBs based on the extended model, which used the unscented Kalman filter (UKF) for parameter identification, is compared with the experimental results. Comparison results show that the predicted hysteretic curves can be in good agreement with the experimental results. The nonlinear dynamic analyses using the extended model are then carried out to explore the seismic performance of the RC structures with SCEBs. The analysis results demonstrate that the SCEB can effectively reduce the residual displacements of the RC structures, but slightly increase the acceleration.