• Phonetics and Speech Sciences
• /
• v.5 no.1
• /
• pp.81-90
• /
• 2013

During adolescence the mutational period is characterized by the changes in the laryngeal structure, the length of the vocal cords, and a tone of voice. Usually, adolescents at 15 or 16 reach the voice of adults but the mutational period is sometimes delayed. Therefore, studies on the voice of adolescents between 16 ~ 18 right after the mutational period are required. Accordingly, this paper attempted to provide basic data about the normal standard for patients with voice disorders during this period by evaluating the vocal characteristics of males and females between 16 ~ 18 with an objective device bycomparing and analyzing them by sex and age. The study was conducted on a total of 60 subjects composed of each 10 subjects of each age. The vocal analysis was conducted by MPT (Maximum Phonation Time) measurement, sustained vowels and sentence reading. As for /a/ sustained vowels, fundamental frequency, hereinafter referred to as $F_0$, jitter, shimmer, noise-to-harmonic ratio, hereinafter referred to as NHR were measured by using the Multi-dimensional voice program (MDVP) among the Multi-Speech program of Computerized Speech Lab (Kay Elemetrics). The sentence reading, mean $F_0$, maximum $F_0$ and minimum $F_0$ were measured using the Real-Time Pitch (RTP) Model 5121 among the Multi-Speech program of Computerized Speech Lab (Kay Elemetrics). As a result, according to sex, there were statistically significant differences in $F_0$, jitter, shimmer, mean $F_0$, maximum $F_0$, and minimum $F_0$; and according to age, there were statistically significant differences in MPT. In conclusion, the voice of the adolescents between 16 ~ 18 reached the maturity levels of adults but the voice quality which can be considered on the scale of voice disorders showed transition to the voice of an adult during the mutational period.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.4
• /
• pp.146-153
• /
• 2008

In this paper, a integrated phase-locked loop(PLL) as a clock multiphase generator for a high speed serial link is designed. The designed PLL keeps the same bandwidth and damping factor by using programmable current mirror in the whole operation frequency range. Also, the close-loop transfer function and VCO's phase-noise transfer function of the designed PLL are obtained with circuit netlists. The self impedance on board-mounted chip is calculated according to sizes and positions of decoupling capacitors. Especially, the detailed self-impedance analysis is carried out between frequency ranges represented the maximum gain in the close-loop transfer function and the maximum gain in the VCO's phase noise transfer function. We shows PLL's jitter characteristics by decoupling capacitor's sizes and positions from this result. The designed PLL has the wide operating range of 0.4GHz to 2GHz in operating voltage of 1.8V and it is designed 0.18-um CMOS process. The reference clock is 100MHz and PLL power consumption is 17.28mW in 1.2GHz.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.8 no.1
• /
• pp.44-48
• /
• 1997

Anatomic and physiological changes of the larynx with advancing age result in morphologic changes of the vocal fold and reduced control of the phonatory mechanism in elderly individuals and are reflected in increased unstability of fundamental frequency (Fo). The purpose of this study is to increase current understanding of acoustic and stroboscopic characteristics of normal elderly persons voices. First, phonated /a/ vowel productions by 40 normal adults (20 to 40 years, 20 men and 20 women) and 40 normal elderly persons (60 to 80 years,20 men and 20 women) were analyzed, using CSL (model 4300B) acoustic analysis software, to obtain acoustic measures related to fundamental frequency stability nd vocal resonance characteristics. Second, stroboscopic images of the vocal fold behavior in all subjects were analyzed by experienced specialists. In the men, fundamental frequency variation (vFe) (p＜0.01), jitter. (p＜0.05), and shimmer (p＜0.05) for the older group were significantly higher than the value for the adult group. In the stroboscopic findings, edema of vocal fold had a significant finding in aged men (15%). In the women, vFo (p＜0.05), jitter (p＜0.05), and noise to harmonic ratio (NHR) (p＜0.05) for the older group were significantly higher than the value for e adult group and first formant frequency (F1) (p＜0.01) and second formant frequency (F2) (p＜0.01) for. the older group were significantly lower than the value for the adult group. In the stroboscopic findings, vocal fold atrophy had a significant finding in aged women (25%). Frequency stability, as reflected by vFo, jitter, shimmer, and NHR, decreases with advancing age in men and women and spectral analysis of phonated /a/ vowel productions reveals the lowering of the frequency of F1 and second F2 with advancing age, especially in aged women. Change in the mass of vocal folds, due to atrophy or edema, is considered to be the greatest factor in these acoustic changes.

• IEIE Transactions on Smart Processing and Computing
• /
• v.5 no.3
• /
• pp.207-214
• /
• 2016

Optical communication systems are rapidly spread following increases in data traffic. In this work, a 32-Gb/s inductorless output buffer circuit with adjustable pre-emphasis is proposed. The proposed circuit consists of an output buffer circuit and an emphasis circuit. The emphasis circuit emphasizes the high frequency components and adds the characteristics of the output buffer circuit. We proposed a design method using a small-signal equivalent-circuit model and designed the compensation characteristics with a 65-nm CMOS process in detail using HSPICE simulation. We also realized adjustable emphasis characteristics by controlling the voltage. To confirm the advantages of the proposed circuit and the design method, we fabricated an output buffer IC with adjustable pre-emphasis. We measured the jitter and eye height with a 32-Gb/s input using the IC. Measurement results of double-emphasis showed that the jitter was 14% lower, and the eye height was 59% larger than single-emphasis, indicating that our proposed configuration can be applied to the design of an output buffer circuit for higher operation speed.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.24 no.1
• /
• pp.5-13
• /
• 2014

Number of components and payload systems installed in satellites were found to be exposed to various disturbance sources such as the reaction wheel assembly, the control moment gyro, coolers, and others. A micro-level of vibration can introduce jitter problems into an optical payload system and cause significant degradation of the image quality. Moreover, the prediction of on-orbit vibration effects on the performance of optical payloads during the development process is always important. However, analyzing interactions between subsystems and predicting the vibration level of the payloads is extremely difficult. Therefore, this paper describes the analytical and experimental approach to microvibration effects on satellite optical payload performance with integrated jitter analysis frame-work, microvibration emulator and satellite structure testbed.

• Proceedings of the IEEK Conference
• /
• 2000.06a
• /
• pp.209-212
• /
• 2000

In this paper, effect of imperfect power control on performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access (DS/CDMA) system. The multipath fading channel is modeled as a two-ray Rayleigh fading model. Power control error is modeled as a log-normally distributed random variable. The tracking performance of DLL (delay-locked-loop) is evaluated in terms of tracking jitter and mean-time-to-lose-lock (MTLL). From the simulation results, it is shown that the PN tracking performance is very sensitive to the power control error.

• Journal of the Korean Data and Information Science Society
• /
• v.16 no.4
• /
• pp.871-877
• /
• 2005

The purpose of this paper is to identify the CPU temperatures on traffic processing between two servers system. To test this model, this research applies multi-generator and resource reservation protocol that produce various types of traffics. The empirical results indicate that $56^{\circ}C\mp9^{\circ}C$ of CPU temperature is suitable when 250-300 traffics with 10-15kb per a packet are supplied. And also, no jitter delay time is showed in these cases.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1986.04a
• /
• pp.14-17
• /
• 1986

In this paper, it is studied on the properties of the transmission signal for being tolerant to the timing jitter at the receiver, when an ideal low pass filter is used as the pulse shaper. A model for the transmission system with minimum bandwidth is presented and the related parameters to the tolerance or stability are explained. It has been proven that the necessary condition for a stable signaling is the same as the sufficient one.

• Journal of IKEEE
• /
• v.19 no.4
• /
• pp.500-505
• /
• 2015

Through Montecarlo simulation, this study compares how accurately the existing three phase deviation models estimate the time-varying variance of a planar oscillator perturbed by Gaussian noises. The comparison reveals that Kaertner model estimates the time-varying variance with about 1000 times higher accuracy than ISF or PP model exhibits. Additionally, it finds that the estimation accuracy of PP model is somewhat higher than that of ISF model.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39A no.8
• /
• pp.481-487
• /
• 2014

In this paper, we have proposed gigabit serial transceiver based on backplane architecture at the satellite communication digital transponder. The transponder supports the full combinational switching function with broadband multi-channel using programmable device - Xilinx space-grade Virtex-5 FPGA. In order to implement the switching function, GTX transceiver solution inside Virtex-5 FPGA is used. Also hardware implementation is simple because of no additional component. In order to use a GTX transceiver, signal integrity(SI) simulation of PCB design is essential. We investigate the characteristics of the S-parameter, eye diagram, channel jitter of GTX transmission line and conform that GTX Transceiver operates without error. Finally the proposed PCB design will be utilized at satellite communication digital transponder EQM-2(Engineering Qualification Model-2).