• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.12
• /
• pp.2374-2379
• /
• 2011

The fundamental frequency of the voiced speech is estimated using the instantaneous frequency based on the symmetric higher order differential energy operator. The instantaneous frequency based on the symmetric higher order energy operator shows better frequency estimation result since it is aligned to the time instance of the signal. The speech is pre-processed by a lowpass filter to remove higher frequency components. Then, it is processed by the instantaneous frequency to obtain the fundamental frequency estimates. The symmetric higher order energy operator has been used as an indicator to determine the voiced/unvoiced speech. The fundamental frequency estimates are further processed by a moving average filter to obtain the monotonically changed estimates. The obtained fundamental frequency estimates have been compared with the spectrogram of the speech to confirm its accuracy.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.51-51
• /
• 2000

The ambiguity resolution is an essential task for the precise carrier phase differential GPS. In practice, however, there are still many problems in resolving the ambiguity in kinematic mode, especially in the urban areas. The multipath in received signal, the frequent change in visible satellites, and the cyclic slips make the ambiguity resolution very difficult task in real-time operation. In this paper, we consider a differential positioning with the float ambiguity that is free from the integer constraint. The float ambiguity estimation if carried out by the Kalman filter. The float and fixed ambiguities are combined together to determine the position in real-time kinematic mode.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.159-162
• /
• 2000

Novel simulated floating inductor (SFI) using fully-differential operational transconductance amplifier (FOTA) is presented. The SFI only consists of two FOTA and a capacitor. A ladder-type third-order elliptic low-pass filter is also presented for the SFI’s application. The theory of operations described and the simulation results are used to verify theoretical predictions. The SFI shows close agreement between predicted behavior and simulation performance. The simulation results that the SFI have The temperature coefficient of-179 ppm/$^{\circ}C$ and Q factor of 120 at 200kHz at supply voltage ${\pm}$5 V.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.6
• /
• pp.51-57
• /
• 1997

Low-voltage, low-power gm-C filter utilizing newly dveloped operational transconductance amplifier (OTA) is described in this paper. The OTA has only two MOS transistors in saturation region between $V_{DD}$ and GND, and thus low voltage operation is possible. To improve the linearity, the OTA is made differential. Common mode feedback, essential in differential circuit, requires no additional implemented in $0.8\mu\textrm{m}$ CMOS process, and the center frequency can be controlled from 15MHz with 3.0V single power supply.

• Journal of Electrical Engineering and information Science
• /
• v.3 no.3
• /
• pp.373-384
• /
• 1998

This paper presents a maneuvering target model with the maneuver dynamics modeled as a jump process of Poisson-type. The jump process represents the deterministic maneuver(or pilot commands) and is described by a stochastic differential equation driven by a Poisson process taking values a set of discrete states. Employing the new maneuver model along with the noisy observations described by linear difference equations, the author has developed a new linear, recursive, unbiased minimum variance filter, which is structurally simple, computationally efficient, and hence real-time implementable. Futhermore, the proposed filter does not involve a computationally burdensome technique to compute the filter gains and corresponding covariance matrices and still be able to track effectively a fast maneuvering target. The performance of the proposed filter is assessed through the numerical results generated from the Monte-Carlo simulation.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.547-548
• /
• 2008

Linearity improvement technique of transconductor is presented in the paper. In order to certify the linearity improvement of proposed transconductor, the 3rd-order Elliptic low-pass Gm-C filter which provides 5MHz cutoff is implemented by using the transconductor. According to the IIP3 measurement result of filters, proposed filter has higher IIP3 than normal source-degeneration filter; the In-band IIP3 of proposed and normal filter are 10.1 dBm and 7.5 dBm respectively. The filter is fabricated in 1P6M $0.18-{\mu}m$ CMOS while consuming the 3.3mW with 1.8 Vdd. The in-band input-referred noise voltage is $62.3{\mu}Vrms$ and the SFDR is 54.1 dB.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.6
• /
• pp.760-768
• /
• 2000

Filter efficiency of electrically charged particle in uncharged fibrous filter was measured. In previous studies, the effect of charged particle on filter efficiency was investigated but there was difficulty in measuring of image effect that is appeared at the charged small particle. We could easily measure the image effect with charging small particles by photoelectric charging. The spark discharge aerosol generator and a differential mobility analyzer (DMA) were used to generate sub-micron monodisperse particles (${\leq}200$ nm). The generated particles were charged in photoelectric charging process using ultraviolet lamp and electric field. The filter efficiency of the charged particles, classified by another DMA, was measured in filter tester using a condensation nucleus counter (CNC) as function of particle diameter, particle charge and airflow velocity. It is shown that the filter efficiency increases with increasing charge number of the particle and is affected by particle size and flow velocity. Single fiber filter efficiency mainly depends on image force parameter and peclet number. The peclet number was not considered at previous other papers. We propose a modi fied experimental correlation as function of image force parameter and peclet number.

• Journal of Biomedical Engineering Research
• /
• v.36 no.1
• /
• pp.22-30
• /
• 2015

Melanoma is originated from the melanocyte producing the melanin which determines the complexion, and it has the highest mortality among skin cancers. Acral lentiginous melanoma(ALM) arises from extremities such as hands, feet or fingernails. Since the appearance of ALM is different from melanoma on the body, conventional auto diagnosis systems for melanoma is inappropriate to detect ALM. Therefore, ALM is typically difficult to distinguish from general nevus, resulting in delayed diagnosis and bad prognosis. In this paper, we firstly introduce a determination method for ALM by dermatologists and propose a method to rotate dermoscopic images automatically as a pre-processing for facilitating the easy determination of ALM and to select the optimal value of the Gaussian differentiation filter parameter which is significant for precise pattern extraction using the scale space analysis. From experimental results, it is shown that there exists the consistency between empirical values of the Gaussian differential filter parameter and optimal values derived from the scale space analysis to distinguish nevus and ALM.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.4
• /
• pp.38-46
• /
• 2011

This paper presents roll angle estimator which used Kalman filter. Recently, the uses of the ELSD (Electronic Limited Slip Differential) and TVD(Torque Vectoring Differential) for vehicle yaw control are studied in many researches. However the roll angle can be negative effect of ELSD and TVD control. Therefore the information of roll angle can be used for vehicle yaw control. Moreover it can be used for rollover prevent control. Recently, most of the vehicles use lateral acceleration and yaw rate sensor. In this paper, design of Kalman filter which used lateral acceleration and yaw rate information is developed. In this paper, in order to verify the estimator ability, the CarSim and Matlab/Simulink are used.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.1
• /
• pp.61-67
• /
• 2011

In this paper, a new method for effective video coding is studied. Picture set filter is proposed for preserving compression ratio and video quality. This filter controls the compression ratio of each frame depending on the correlation to the reference frame by selectively eliminating less important high-resolution areas. Consequently, video quality can be preserved and bit rate can be controlled adaptively. In the simulation, to test the performance of the proposed coding method, comparisons with the full search block matching algorithm and the differential image coding algorithm are made. In the former case, video quality, compression ratio and encoding time is improved. In the latter case, video quality is degraded, but compression ratio and encoding time is improved. Consequently, the proposed method shows a reasonably good performance over existing ones.