• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.99-103
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• 2022

Millimeter-wave tracking radars operate in various environmental restrictions, thus they demand stable power sources with low noise level under high fluctuation of input voltage. This paper presents the design and implementation of the compact power supply with max power of 727 W for Ka-band tracking radar applications. To meet requirements of voltage accuracy and system efficiency for transceiver circuits, upper plates of buck converters are attached on the covers of power supply for efficient heat dissipation. The proposed power supply achieves system efficiency of 88.4 %, output voltage accuracy of ±2 % and noise level of <1% under full load conditions.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.237-246
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• 2022

Among the technologies of the 4th industrial revolution, drones that have grown rapidly and are being used in various industries can be operated by the pilot directly or can be operated automatically through programming. In order to be controlled by a pilot or to operate automatically, it is essential to predict and analyze the optimal path for the drone to move without obstacles. In this paper, after securing and analyzing the pilot training dataset through the unmanned aerial vehicle piloting training platform designed through prior research, the profile of the dataset that should be preceded to search and derive the optimal route of the unmanned aerial vehicle was designed. The drone pilot training data includes the speed, movement distance, and angle of the drone, and the data set is visualized to unify the properties showing the same pattern into one and preprocess the properties showing the outliers. It is expected that the proposed big data-based profile can be used to predict and analyze the optimal movement path of an unmanned aerial vehicle.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.206-212
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• 2013

Information and Communications Technologies(ICT) represented by Multimedia, Virtual Reality and Network could be used as the better ways to preserve and restore the original shape of cultural contents. This paper presents the detailed methods of Multimedia and Virtual Reality technologies to digitally implement the traditional wooden buildings which are called as a typical 'Korean Cultural Content." We implemented a 3D modeling of architectural parts, realized a roof curve, and texture-mapped the material qualities of traditional wooden buildings by using Graphic techniques. In addition, the information, which is implemented by marker-based Augment Reality, for the traditional wooden buildings can be obtained through the mobile appliances such as a smart phone. We, also, presented how to practically use the implemented digital Korea traditional wooden buildings.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1
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• pp.47-53
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• 2004

We propose a new speech enhancement algorithm based on left-right Hidden Markov Model (HMM) with state decision using Log-likelihood Ratio Test (LRT). Since the conventional HMM-based speech enhancement methods try to improve speech quality for all states, they introduce huge computational loads inappropriate to real-time implementation. In the left-right HMM, only the current and the next state are considered for a possible state transition so to reduce the computational complexity. In this paper, we propose a method to decide the current state by using the LRT on the previous state. Experimental results show that the proposed method improves the speed up to 60% with 0.2∼0.4 dB degradation of speech quality compared to the conventional method.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.65-69
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• 2006

Cellular network evolution and development of multi-function cellular phones introduce new mobile business mode. Cellular operators provide mobile internet services using the mobile browser such as ME and WAP and the mobile multimedia platform such as WIPI, J2ME, and BREW. New mobile applications are developed using mobile platforms provided by cellular operators as cellular phones having multimedia solutions such as camera, MP3, MPEG, 3D game engine, DMB, PAN such as bluetooth, IrDA, W-LAN, and location information using GPS are developed. Content providers have problems of redevelopment of a mobile application for different mobile platforms. In this paper, we propose a conversion solution for interoperability of applications developed on different mobile platforms of WIPI and BREW. We analyze APIs of WIPI and BREW and develop conversion solutions.

• 전자공학회논문지 IE
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• v.43 no.1
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• pp.16-24
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• 2006

This paper is aimed to develope of an integrated BCI(Brain Computer Interface System) that make possible for simultaneous multichannel data process and used extra cellular neural activity from the vestibular system instead of electroencephalogram signals for more precision control. The electrical properties pre-amplifier are 47.6 dB of gain, 0.005 % of distortion at 100 Hz, 12M$\Omega$ of input impedance. Window discriminator used two CPU with difference role to increase processing speed so that sampling frequency was 87 kHz. The designed window discriminator has more not only two times in signal resolution power but also ten times in error discrimination power than commericially available discriminator. The proposed method decreases 100 times in amount of integrated data then BCI system during 100 ms.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.191-199
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• 2014

Recently, researches to facilitate utilization by small and medium business (SMB) of cloud computing and big data paradigm, which is the booming adoption of IT area, has been on the increase. As one of these efforts, in this paper, we design and implement the prototype to tentatively build up Hadoop cluster under private cloud infrastructure environments. Prototype implementation are made on each hardware type such as single board, PC, and server and performance is measured. Also, we present the integrated verification results for the data analysis performance of the analysis software system running on top of realized prototypes by employing ASA (American Standard Association) Dataset. For this, we implement the analysis software system using several open sources such as R, Python, D3, and java and perform a test.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.310-318
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• 2015

In this paper, dual-port eFuse OTP (one-time programmable) memory cells with smaller cell sizes are used, a single VREF (reference voltage) is used in the designed eFuse OTP IP (intellectual property), and a BL (bit-line) sensing circuit using a S/A (sense amplifier) based D F/F is proposed. With this proposed sensing technique, the read current can be reduced to 3.887mA from 6.399mA. In addition, the sensing resistances of a programmed eFuse cell in the program-verify-read and read mode are also reduced to $9k{\Omega}$ and $5k{\Omega}$ due to the analog sensing. The layout size of the designed 32-bit eFuse OTP memory is $187.845{\mu}m{\times}113.180{\mu}m$ ($=0.0213{\mu}m2$), which is confirmed to be a small-area implementation.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.245-255
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• 2002

This thesis deals a method to deliver more realistic sound by cancelling the cross-talk which is inherent to the 5.1 channel speaker system. The acoustical model for cross-talk cancellation is the free field model. This model minimizes distortion of sound. I used the bark scale sound quality compensation which based on psycho-acoustic. For the surround channels, band-limited sound quality compensation is performed in the frequency domain. I also performed the sound quality assessment test on the traditional 2 channel stereo and 5.1 channel system. This test is performed in the test chamber which satisfies the ITU-R specifications. I uses the IACC (Inter-Aural Cross-Correlation) to determine the preferences of the amateur and the golden ear experts to asses the trans-aural filter. According to the result from the proposed method, I got more the 38 dB separation rates with the Dolby standard speaker array. The results on the diffusion by the subjective test with the experts shows 0.4 point increased then before.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.313-322
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• 2005

In this paper, we implement and verify performance monitor for parallel signal processing system, using DSP Starter Kit(DSK) of which the basic Processor is TMS302C6711 chip. The key ideas of this performance monitor is, using Real Time Data Exchange(RTDX) for the Purpose of real-time data transfer and function of DSP/BIOS, the ability to measure the Performance measure like DSP workload, memory usage, and bridge traffic. In the simulation, FFT, 2D FFT, Matrix Multiplication, and Fir Filter, which are widely used DSP algorithms, have been employed. Using performance monitor and Code Composer Studio from Texas Instrument(Tl) , the result has been recorded according to different frequencies, data sizes, and buffer sizes for a single wave file. The accuracy of our performance monitor has been verified by comparing those recorded results.