• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.9
• /
• pp.377-384
• /
• 2015

In this paper we propose a visualization tool for distortion-free time-series matching. Supporting distortion-free is a very important factor in time-series matching to get more accurate matching results. In this paper, we visualize the result of time-series matching, which removes various time-series distortions such as noise, offset translation, amplitude scaling, and linear trend by using moving average, normalization, linear detrending transformations, respectively. The proposed visualization tool works as a client-server model. The client sends a user-selected time-series, of which distortions are removed, to the server and visualizes the matching results. The server efficiently performs the distortion-free time-series matching on the multi-dimensional R*-tree index. By visualizing the matching result as five different charts, we can more easily and more intuitively understand the matching result.

• Proceedings of the IEEK Conference
• /
• 2000.11d
• /
• pp.17-20
• /
• 2000

This paper describes a shape-based object recognition algorithm using multiple distance images. For the images containing dense edge points and noise, previous Hausdorff distance (HD) measures yield a high ms error for object position and many false matchings for recognition. Extended version of HD measure considering edge position and orientation simultaneously is proposed for accurate matching. Multiple distance images are used to calculate proposed matching measure efficiently. Results are presented for visual images and infrared images.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.8 no.1
• /
• pp.71-87
• /
• 1990

This paper presents a simple algorithm to obtain three dimensional information of an object. In the preprocessing of the stereo matching,feature point informations of stero image must be less sensitive to noise and well liked the correspondance problem. This paper described a simple technique of struture feature extraction of 3-D object and used edge-end point expanding method for unconnected line instade of Hough transform. The feature such as corner point and their angles are used for matching problem. The experimental results show that the described algorithm is a useful method for stereo correspondence problem.

• Proceedings of the IEEK Conference
• /
• 2007.07a
• /
• pp.127-128
• /
• 2007

A dual band LNA is designed to set input matching and noise matching with source transmission feedback for wireless LAN applications. Some design techniques for the transmission line feedback of the dual band LNA have been developed with input and output design equations. The measured results shows close agreement with the simulated performance.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.345-346
• /
• 2006

In this paper, we propose the noise suppressor with the psychoacoustic model and wavelet packet transform. The objective of the scheme is to enhance speech corrupted by colored or non-stationary noise. If corrupted noise is colored, subband approach would be more efficient than whole band one. To avoid serious residual noise and speech distortion, we must adjust the Wavelet Coefficient threshold. In this paper, the subband is designed matching with the critical band. And WCT is adapted by noise masking threshold(NMT) and segmental signal to noise ratio(seg_SNR). Consequently this work improve the PESQ-MOS about 0.23 in the case of coded speech.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.57-60
• /
• 2004

This paper presents multibit Sigma-Delta ADC using Leslie-Singh Structure to Improve nonlinearity of feedback loop. 4-bit flash ADC for multibit Quantization in Sigma Delta modulator offers the following advantages such as lower quantization noise, more accurate white-noise level and more stability over single quantization. For the feedback paths consisting of DAC, the DAC element should have a high matching requirement in order to maintain the linearity performance which can be obtained by the modulator with a multibit quantizer. Thus a Sigma-Delta ADC usually adds the dynamic element matching digital circuit within feedback loop. It occurs complexity of Sigma-Delta Circuit and increase of power dissipation. In this paper using the Leslie-Singh Structure for improving nonliearity of ADC. This structure operate at low oversampling ratio but is difficult to achieve high resolution. So in this paper propose improving loop filter for single-bit feedback multi-bit quantization Sigma-Delta ADC. It obtained 94.3dB signal to noise ratio over 615kHz bandwidth, and 62mW power dissipation at a sampling frequency of 19.6MHz. This Sigma Delta ADC is fabricated in 0.25um CMOS technology with 2.5V supply voltage.

• International Journal of Contents
• /
• v.2 no.1
• /
• pp.29-33
• /
• 2006

The common-source low noise amplifier(LNA) with inductive degeneration using a genetic algorithm is designed and tested for a down converter in an industrial, scientific and medical (ISM) band application and a wireless broadband internet service (WiBro). The genetic algorithm optimizes the reflection coefficients to be well matched the input and output ports between multistage transistor amplifiers, and it generates low voltage standing wave ratio as well as gain flatness of the amplifier. The stability and the gain flatness of the LNA have been improved by combining the matching circuits and the series feedback microstrip lines with inductive degeneration at common-source port. In the frequency range of ISM band and WiBro application operating at $2.3GHz{\sim}2.5GHz$, the measured power gain and maximum voltage standing wave ratio (VSWR) of the LNA are $41{\pm}0.5dB$ and 1.3, and the noise figure of the LNA is lower than 0.85dB. The above results are agreed well with the theoretical values of the amplifiers.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.6
• /
• pp.818-823
• /
• 2014

A high-gain wideband low noise amplifier (LNA) using $0.25-{\mu}m$ Gallium-Nitride (GaN) MMIC technology is presented. The LNA shows 8 GHz to 15 GHz operation by a distributed amplifier architecture and high gain with an additional common source amplifier as a mid-stage. The measurement results show a flat gain of $25.1{\pm}0.8dB$ and input and output matching of -12 dB for all targeted frequencies. The measured minimum noise figure is 2.8 dB at 12.6 GHz and below 3.6 dB across all frequencies. It consumes 98 mA with a 10-V supply. By adjusting the gate voltage of the mid-stage common source amplifier, the overall gain is controlled stably from 13 dB to 24 dB with no significant variations of the input and output matching.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.259-264
• /
• 2006

It is well known that the uncertainty of the covariance parameters of the process noise (Q) and the observation errors (R) has a significant impact on Kalman filtering performance. Q and R influence the weight that the filter applies between the existing process information and the latest measurements. Errors in any of them may result in the filter being suboptimal or even cause it to diverge. The conventional way of determining Q and R requires good a priori knowledge of the process noises and measurement errors, which normally comes from intensive empirical analysis. Many adaptive methods have been developed to overcome the conventional Kalman filter's limitations. Starting from covariance matching principles, an innovative adaptive process noise scaling algorithm has been proposed in this paper. Without artificial or empirical parameters to be set, the proposed adaptive mechanism drives the filter autonomously to the optimal mode. The proposed algorithm has been tested using road test data, showing significant improvements to filtering performance.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.1
• /
• pp.39-45
• /
• 2018

Compressive sensing allows recovering an original signal which has a small dimension of the signal compared to the dimension of the entire signal in a short period of time through a small number of observations. In this paper, we proposed a method for detecting tonal signal which caused by the machinery component of a vessel such as an engine, gearbox, and support elements. The tonal signal can be modeled as the sparse signal in the frequency domain when it compares to whole spectrum range. Thus, the target tonal signal can be estimated by S-OMP (Simultaneous-Orthogonal Matching Pursuit) which is one of the sparse signal recovery algorithms. In simulation section, we showed that S-OMP algorithm estimated more precise frequencies than the conventional FFT (Fast Fourier Transform) thresholding algorithm in low SNR (Signal to Noise Ratio) region.