• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.21-26
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• 2008

In this paper, a novel 622Mbps burst-mode clock and data recovery (CDR) circuit is proposed for passive optical network (PON) applications. The CDR circuits are implemented with 0.35um CMOS process technology. Locking dynamics is accomplished with instantaneous feature and data are sampled at an optimal timing. This is realized by seven different delay configurations, which are generated from precisely-controlled delay buffers. The experimental results show that the proposed CDR circuits are operating as expected, recovering an incoming 622Mbps burst-mode input data without errors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1153-1157
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• 2004

This paper describes a new programmable DLL_based frequency synthesizer. Generally, PLLs have been used for frequency synthesis. Inherent fast locking DLLs are also used for frequency synthesis. However, DLL needs a frequency multiplier for various frequencies. A conventional frequency multiplier used in DLL has a restriction in which a multiple is fixed. However, the proposed DLL can generate clocks which are from 6 times to 10 times of the reference clock. Frequency range of the proposed DLL is from 600MHz to 1GHz. The idea has been confirmed by HSPICE simulations in a $0.35-\mu\textrm{m}$ CMOS process.

• Journal of IKEEE
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• v.22 no.4
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• pp.1158-1162
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• 2018

A fast-lock multiplying delay-locked loop (MDLL)-based digital clock frequency multiplier with an anti-harmonic lock capability is presented. The proposed digital frequency multiplier utilizes a new most-significant bit (MSB)-interval search algorithm to achieve fast-locking time without harmonic lock problems. The proposed digital MDLL frequency multiplier is designed in a 65nm CMOS process, and the operating output frequency range is from 1 GHz to 3 GHz. The digital MDLL provides a programmable fractional-ratio frequency multiplication ratios of N/M, where N = 1, 4, 5, 8, 10 and M = 1, 2, 3, respectively. The proposed MDLL consumes 3.52 mW at 1GHz and achieves a peak-to-peak (p-p) output clock jitter of 14.07 ps.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.171-174
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• 1999

The objective of this study is to investigate the properties of fine particles in the process of producing crushed fine aggregates under various fine particle contents. According to the test results, when fine particles are added as substitution of aggregates by about 10%, it shows that the qualities of interlocking block such as compressive strength, flexural strength and absorption ratio are improved. The application of fine particles provide various advantages in the sides of recycling of materials

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1201-1204
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• 2003

This paper described a replica-delay adaptive lock-acquisition scheme for high-speed DLLs. The proposed scheme provides the fast and correct locking cycle that is variable according to the magnitude of the arbitrary replica delay (fixed delay). The scheme guarantees the wide operation range and the fast lock-aquisition time. It has been confirmed by HSPICE simulations in a 0.35${\mu}{\textrm}{m}$ CMOS process.

• The Journal of Korean Association of Computer Education
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• v.11 no.4
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• pp.71-83
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• 2008

The recent advances of the information technology have motivated lots of research efforts to develop new computer-aided teaching and learning methodologies on various computer science topics, such as data structures, operating system, computer networks, and computer architecture. However, there have been only few studies to educate the database subject although it is one of the most important topics in the computer science. Specifically, among the various issues in the database subject, a learner often suffers to understand the mechanism of the concurrency control and recovery of database transaction in the database because it highly interacts with other functions in the database. Obviously, an intelligent visualization tool can help a learner to understand the process of the concurrency control and the recovery of database transaction. The purpose of this study is to develop an efficient visualization tool which can help users understand the two phase locking protocol (2PLP)-based concurrency control. Specifically, this visualization tool is designed to encourage a users' participation and raise their interest by visualizing the process of transactions and allowing users to specify and manipulate their own transactions.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.333-336
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• 2000

Modem standard CMOS process technology suffer from so large amount of PVT i.e process, voltage and temperature variation over 30% of its desired value that accurate resistor value is hard to be achieved. A filter using switched-capacitor(SC) circuit has a time constant proportional to relative capacitor area ratio rather than its absolute value. If the PLL's loop filter were made out of SC circuit, there could be much less PVT variation problem. Furthermore, programmability on the loop filter can be achieved In this paper, we present the PLL with SC loop filter. The accuracy provided by SC filter would be helpful to enhance PLL's locking behaviour.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.3
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• pp.71-79
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• 2006

ABS is a safety device for preventing wheel locking in a sudden baking. Its control methods are classified into three types; deceleration control, wheel slip control and deceleration/acceleration control. The braking force takes the influence of the friction coefficient between road and tire, which in turn depends on the wheel slip as well as road conditions. In this paper, it has been proposed the wheel slip control system to apply the adaptive control method at the ABS. To maintain wheel slip to desired wheel slip, it have been done the linearization and designed the adaptive controller to apply gradient method based on the reference model. It is illustrated by computer simulations that the proposed control system gives good performances and adaptation to parameter variation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.77-82
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• 2011

The piston-cylinder mechanism is widely adopted in the hydraulic machine components. In these cases, the hydrodynamic pressures are generated in the clearance gap between the piston and cylinder under lubrication action of the piston. Under the eccentric and tilted condition of the piston in the cylinder bore, the non-symmetric pressure distributions in the circumferential direction result in lateral forces. When the lateral forces act as increasing the eccentricity and tilting ratios, excessive wear can be result in cylinder and piston which are well known 'hydraulic locking' phenomena. In this paper, the hydrodynamic pressures generated in the clearance are measured using a stationary piston and moving cylinder apparatus. The experimental results showed that the hydrodynamic pressure distributions are highly affected by the speed and eccentricity of the cylinder and the oil viscosity.

• Clinics in Shoulder and Elbow
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• v.13 no.2
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• pp.260-265
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• 2010

Purpose: To report the clinical results of two cases of coronoid process fractures that were treated with volar plating through a medial approach. Materials and Methods: Two fractures of the coronoid process that needed to be fixed were managed with open reduction and internal fixation through a medial approach using 2.4 mm locking compression plates (Compact Hand set$^{(R)}$, Synthes, Switzerland). The patients were followed up for 14 months and 17 months and were evaluated using the Mayo Elbow Performance Score (MEPS). Results: The MEPS was 95 for Case 1 and 100 for Case 2. Active elbow joint motions were $5^{\circ}-120^{\circ}$ (Case 1) and $0^{\circ}-130^{\circ}$ (Case 2). Supination and pronation fully recovered. Conclusion: Satisfactory results can be obtained in cases of coronoid process fractures because volar plating through a medial approach allows sound fixation and early mobilization of the elbow joint.