• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.2C
• /
• pp.91-99
• /
• 2003

In this paper, We analyze performance of ZFE MUD receiver in DSSS unidirectional wireless transceiver operating in 2.4㎓ ISM band and indoor environment. This system has the shortcomings that many burst error is occurred because of long term deep fade experienced by some user and impossibility of power control. Therefore, the solution to this problem is important because the performance of DS-CDMA system is guaranteed under, the perfect power control. MUD receive. which improves the performance of this system is not required to perform rigorous power control and is able to remove MAI using linear equalization. From the result of performance comparison, we show that ZFE MUD receiver is more adequate for this system than other receivers.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1993.06a
• /
• pp.1159-1162
• /
• 1993

We describe six important defuzzification methods and their respective merits and shortcomings, dependent on the rules, domains, etc. Furthermore, we present an alternative approach, the so called ξ-Quality defuzzification method, for the case that the output fuzzy sets have different shape or are asymmetric.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.5 no.1
• /
• pp.75-81
• /
• 1985

The behavior of a plane buoyant jet within the zone of flow establishment(ZFE) which is discharged vertically upward into a stagnant uniform environment, is analyzed by the integral equations of mass, momentum and tracer conservation. The analysis includes the spreading ratio with Froude number and geometry of the potential core of ZFE and the length of ZFE. The central velocity at the end of ZFE is found to be influenced significantly by buoyancy, especially at low discharge Froude number. The results provide the necessary initial conditions for the investigation of the zone of established flow.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.349-350
• /
• 2006

This paper presents very low bit rate speech coder, ZFE-CELP(ZINC Function Excitation-Code Excited Linear Prediction). The ZFE-CELP speech codec is based on a ZINC function and CELP modeling of the excitation signal respectively according to the frame characteristic such as a voiced speech and an unvoiced speech. And this paper suggest strategies to improve the speech quality of the very low bit rate speech coder.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1993.06a
• /
• pp.1390-1393
• /
• 1993

An 8b Fuzzy Coprocessor (FC) is presented that has eight programmable fuzzy algorithms and up to 256 inputs, 64 outputs and 16,384 rules. The 6.4mm2 chip fabricated in 1.0$\mu\textrm{m}$ CMOS technology can be used as a stand-alone device or as a macrocell for microcontrollers. Operating at 20MHz crystal frequency, it has a peak performance of 7.9M rules/s. Perspectives of future FC generations are also outlined, including a 12-16b resolution, additional fuzzy set operations, and optimized inference and defuzzification strategies.

• The Journal of the Acoustical Society of Korea
• /
• v.25 no.6
• /
• pp.282-290
• /
• 2006

This paper proposes a new Digital Reverberator that models Analog Helical Coil Spring Reverberator for guitar amplifiers. While the conventional digital reverberators are proposed to provide better sound field mainly based on room acoustics, no algorithm or analysis of digital reverberators those model Helical Coil Spring Reverberator was proposed. Considering the fact that approximately $70{\sim}80$ percent of guitar amplifiers are still with Helical Coil Spring Reverberator, research was performed based not on Room Acoustics but on Helical Coil Spring Reverberator itself as an effector. After performing simulations with proposed algorithm, it was confirmed that the Digital Reverberator by proposed algorithm provides perceptually equivalent response to the conventional Analog Helical Coil Spring Reverberators.

• Water Engineering Research
• /
• v.3 no.3
• /
• pp.163-176
• /
• 2002

In this study, laboratory experiments have been performed to investigate characteristics of the velocity fields and turbulence for non-buoyant plane jet in the vicinity of the jet nozzle using PIV system. The experimental results show that, in the transition region, the lateral velocity profile is in good agreement with Gaussian distribution. However, the coefficient of Gaussian distribution, $\K_{u,}$, decreases with longitudinal distance in the transition region. The existing theoretical equation for the centerline velocity tends to overestimate the measured data in the transition region. A new equation for the centerline velocity derived by incorporating varying $k_{u}$ gives better agreement with the measured data than the previous equation. The results of the turbulence characteristics show peak values are concentrated on the shear layers. The Reynolds shear stress profile shows the positive peak in the upper layer and negative peak in the lower layer. The turbulent kinetic energy also provides double peaks at the shear layers. The peak of the Reynolds shear stress and the turbulent kinetic energy increases until x/B=8, and then it decreases afterwards.s.