• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.153-158
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• 1996

Delay and jitter are critical factors in the real-time video services over ATM network. Mostly, delay and jitter problem are generated in input buffer when video are multiplexed. In this paper, we analyze delay and jitter of input buffer, and consider efficient control and flexible bandwidth allocation of video traffic. Also, we analyze decision of buffer size related maximum allowable delay.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.2
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• pp.1-9
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• 1993

For frame synchronization in synchronous multiplexer based on SDH (Synchronous Digital Hierarchy), pointer justification mechanism (opinter adjustment) to compensate small frequency differences between the received uline clock and local clock is sed. But these pointer adjustment will introduce jitter onto tributary signal. This paper presents the bit leaking method to reduce those jitter to a level compatible with existing specification, where the simulation shows that this method reduces pointer adjustment jitter.

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.87-94
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• 2006

The purpose of this paper is to measure jitter between two server systems. Given 3 empirical models as user and port parallel server types under some conditions of 100 Mbps and optimal CPU temperature suggested by Lee and Kim(2005), our results are shown; jitter was usually measured above 3000 ms in most empirical cases, jumping points were observed around 250 processing traffics, and port parallel model was optimal in our cases.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.3
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• pp.411-424
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• 2017

An all-digital delay-locked loop (DLL) for a mobile memory interface, which runs at 0.11-2.5 GHz with a phase-shift capability of $180^{\circ}$, has two internal DLLs: a global DLL which uses a time-to-digital converter to assist fast locking, and shuts down after locking to save power; and a local DLL which uses a phase detector with an adaptive phase sampling window (WPD) to reduce jitter accumulation. The WPD in the local DLL adjusts the width of its sampling window adaptively to control the loop bandwidth, thus reducing jitter induced by UP/DN dithering, input clock jitter, and supply/ground noise. Implemented in a 65 nm CMOS process, the DLL operates over 0.11-2.5 GHz. It locks within 6 clock cycles at 0.11 GHz, and within 17 clock cycles at 2.5 GHz. At 2.5 GHz, the integrated jitter is $954fs_{rms}$, and the long-term jitter is $2.33ps_{rms}/23.10ps_{pp}$. The ratio of the RMS jitter at the output to that at the input is about 1.17 at 2.5 GHz, when the sampling window of the WPD is being adjusted adaptively. The DLL consumes 1.77 mW/GHz and occupies $0.075mm^2$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1196-1201
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• 2006

In pointer adjustment systems, 3 byte SDH clocks are controlled for synchronization. Therefore large jitter is generated in that systems. Bit stuffing technique was introduced as method for reducing pointer adjustment jitter. However, the jitter generated in this systems is also not so small. In this paper, the problems in the bit leaking system are analyzed and new bit stuffing technique is introduced to reduce the jitter sufficiently.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2625-2628
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• 2003

Phase locked loops are widely used in many applications such as frequency synthesis, clock/data recovery and clock generation. In nearly all the PLL applications, low jitter and fast locking time is required. Without using adaptive loop filter, this paper proposes very simple method for improving locking time and jitter reduction simultaneously in charge pump PLL(CPPLL) using Daul Phase/Frequency Detector(Dual PFD). Based on the proposed scheme, the lock time is improved by 23.1％, and the jitter is reduced by 45.2％ compared with typical CPPLL.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.522-527
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• 2001

Comprehensive numerical computations are made of side-heated squire cavity which is exposed to zero mean g-jitter. Numerical solutions are acquires to the governing two-dimensional Navier-Stokes equations for a Boussinesq fluid. When the system is exposed to pure sinusoidal g-jitter inclined to the vertical axis, in spite of zero mean gravity there exist non zero net flow fields [8]. The resonance phenomenon are observed in moderate Rayleigh number. And, by comprehensive numerical work, unlike[5], it is found that they are related with the overshoot phenomenon of the sudden gravity up problem.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.38-43
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• 1994

Though normal vocal cords show regular vibration, pathologic vocal cords show irregularity between peaks. Jitter means fluctuation in the time interval between peaks, and Shimmer means cycle to cycle variation in the amplitude of the peaks. We investigated the vocal vibration of Korean normal persons objectively. The fundamental frequency, Jitter, Shimmer and SNR(signal to noise ratio) of normal persons were compared with that of vocal Polyp Patients with CSpeech Program for the possibility of distinguishing the pathologic vocal vibration from normal. The results were as follows ; Comparing the fundamental frequency of vocal Polyp Patients with normal persons, great change was noted only in female cases. But the Jitter and Shimmer of vocal polyp patients were greater than normal significantly in both male and female cases. SNR was lower than normal in vocal polyp patients. In the conclusion, fundamental frequency, Jitter, Shimmer and SNR might be meaningful parameters distinguisuing pathologic vibration from normal.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2E
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• pp.47-54
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• 1997

This paper presents two results on intersymbol interferences in baseband digital communication over an additive white Gaussian noise channel-the interferences due to mismatched square-root raised-cosine filters, in which the filters have different roll-off factors, and / or due to sampling-time jitter. The result for the mismatched filters is that even the jitter-free sampling causes intersymbol interference and it is negligibly small for a wide range of signal-to-noise ratio up to 10dB, for the roll-off factor ranging from 0.2 to 0.5, the mismatch loss being within 0.1dB from the optimum at around 10-6 .For jitter interference an approximation formula for the bit error probability is derived in case of the matched filters, which shows how the roll-off factors and the amount of jitter affect the system performance. The formula is reasonably accurate.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.53-57
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• 2005

In order to measure signal quality of optical disc such as CD or DVD, jitter is used traditionally. The signal attained from a disc by optical pick-up is processed by analog circuits. And then, binary signal can be obtained by using proper silcer. After the signal is changed into binary format, jitter is calculated as a time difference between the binary signal and the reference time. Jitter is used to express the signal quality. In this paper, a new method that is able to offer more precise measurement of the signal quality fur high density optical disc than the jitter is proposed. We named it LPSNR (Level Peak Signal to Noise Ratio). The relationship between bER (bit error rate) and LPSNR is shown in the paper.